Final Report
May 5th, 2014
Team 2A
Submitted by: Michael George, Dylan Heimbach, Thomas Tiarks, Basil Odulukwe
Executive Summary
The objective for this project is to design and build a working turbine driven electrical generator.
The turbine generator must be designed for use with a common household kitchen faucet. The
design must be small, safe and inexpensive. In addition, it needs to be aesthetically pleasing and
practically useful. In our initial research, it was found that three turbines were by far the most
widely used across all industries: the Francis, Kaplan, and Pelton Wheel. It is desirable that the
device is as versatile as possible; our final product has been designed to perform properly in
many different situations. The chosen design is a multiple inlet Pelton wheel. We believe this
design is optimal for the conditions we expect to encounter as it is compact and inexpensive to
manufacture. At this stage our design has been finalized and the final prototype is under
construction. Our current performance efficiency is estimated at 15%. Further testing and
experimentation will continue upon its completion, leading up to production ramp up. According
to our NPV analysis, if we sell at a price of $50 our NPV by the end of year four will be roughly
5 million dollars. Our final turbine will charge battery packs and cell phones directly.
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Table of Contents
1. Introduction................................................................................................................................................. 4
1.1 Problem Statement .................................................................................................................................. 4
1.2 Background Information ......................................................................................................................... 4
1.3 Project Planning ..................................................................................................................................... 4
2. Customer Needs & Specifications ............................................................................................................. 5
2.1 Identification of Customer Needs ........................................................................................................... 5
2.2 Design Specifications.............................................................................................................................. 5
3. Concept Development ................................................................................................................................. 6
3.1 External Search ...................................................................................................................................... 6
3.2 Problem Decomposition ......................................................................................................................... 7
3.3 Concept Generation ................................................................................................................................ 7
3.4 Concept Selection ................................................................................................................................... 8
4. System Level Design ................................................................................................................................... 8
4.1 Modifications to Proposal Sections ........................................................................................................ 8
4.2 Overall Description ................................................................................................................................ 8
4.3 Detailed Drawings .................................................................................................................................. 9
4.4 Final Theoretical Analysis .................................................................................................................... 10
4.5 Component and Material Selection Process for Mass Production ....................................................... 11
4.6 Fabrication Processes for Mass Production ........................................................................................ 11
4.7 Industrial Design .................................................................................................................................. 12
4.8 Economic Analysis ................................................................................................................................ 13
4.8.1 Unit Production Cost ..................................................................................................................... 13
4.8.2 Business Case Justification ............................................................................................................ 13
4.9 Safety..................................................................................................................................................... 13
4.10 Actual Construction Process of Final Prototype ................................................................................ 14
5. Testing........................................................................................................................................................ 15
5.1 Test Procedure and Plan ...................................................................................................................... 15
5.2 Test Results and Discussion of Results ................................................................................................. 16
6. Conclusion and Recommendation ........................................................................................................... 16
7. References .................................................................................................................................................. 18
8. Appendices................................................................................................................................................. 19
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Appendix A: Project Management .............................................................................................................. 19
Appendix B: NPV Analysis ......................................................................................................................... 20
Appendix C: Patent Search ......................................................................................................................... 21
Appendix D: Customer Needs Survey ......................................................................................................... 22
Appendix E: QFD Matrix and Customer Needs AHP Matrix ..................................................................... 23
Appendix F: Concept Screening and Weighted Matrices ........................................................................... 24
Appendix G: Additional Drawings ............................................................................................................. 26
Appendix H: Gantt Chart............................................................................................................................ 31
Appendix I: Analysis Plots .......................................................................................................................... 32
Appendix J: Attestation of Work ................................................................................................................. 38
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1. Introduction
1.1 Problem Statement
The objective for this project is to design and build a working turbine driven electrical generator.
The turbine generator must be designed for use with a common household kitchen faucet. The
design must be small, safe and inexpensive. In addition, it needs to be aesthetically pleasing and
practically useful. The final product must not be more than 4 inches in length from inlet to outlet,
must have an inlet and outlet 3/8 NPT pipe thread, and must be completely self-contained.
1.2 Background Information
While there are a few similar products on the market, nearly all of them focus exclusively on
showerhead and lighting applications. We believe our product can utilize existing technology in
a new way and easily slip into this largely untapped market.
Our team performed extensive research on different turbine designs for this project. We learned
at the outset of the two primary categories of turbine: reaction and impulse. The only impulse
design looked into extensively was the Pelton wheel design; the concept behind a Pelton wheel
has been around for centuries, but the “modern” design was invented in the late nineteenth
century. Fluid strikes the turbine blades and is rapidly directed away in order to achieve
maximum efficiency. [1] Also considered were two reaction turbine designs, the Francis and
Kaplan turbines. Developed around the same time as the Pelton wheel, Francis turbines are
highly efficient and versatile; they force water at controlled pressures around a horizontally
mounted turbine and down an outlet in the center. [2] The Kaplan turbine was developed later on
as a modification of the Francis turbine, designed for high-flow, low-head situations. [3]
1.3 Project Planning
The design process laid out in the Product Design and Development text [4] was used,
summarized as follows into 6 phases: Planning, Concept Development, System-Level Design,
Detail Design, Testing and Refinement, and Production Ramp-Up.
For this project, we have decided to function as equals without a single authoritative figure
making the final decisions. In order to maximize the efficiency of the team, we have established
a Gantt chart (Appendix H) specifying the dates of completion for individual portions of this
design process as well as projected due dates for reports, memos and presentations. For larger
tasks, the workload has been divided equally between all team members according to the
strengths and weaknesses spelled out in our Team Contract, summarized in Appendix A.
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2. Customer Needs & Specifications
2.1 Identification of Customer Needs
For this product, the target consumers included include homeowners, farmers, and ranchers.
Brainstorming, internet browsing, and surveying data from similar consumer products allow us
to compile the potential consumer needs. This was done through the use of a survey given to 17
Penn state faculty homeowners. From this compilation, seven needs were identified. (Appendix
D) The device had to be small and could not obstruct sink space, in other words if the device
took up too much space it would be too bulky for the user. The device had to be quiet and the
noise generated had to be low. The device had to be aesthetically pleasing; it had to not affect
water speed. It had to be easy to use, inexpensive and portable. Based on the stated importance
and ranking that the customers provided, we were able to rank the least important to most
important needs shown in a bar graph below (Figure 1).
Customer Needs
Quiet
Aesthetically Pleasing
Maintains usable water speeds
Easy to use
Inexpensive
Portability
Size
Safety
0%
5%
10%
15%
20%
25%
30%
Level of Importance
Figure 1: Customer Needs Chart
2.2 Design Specifications
Our most important customer needs were found to be the size and price of the final product.
Because of this, throughout the design process the heaviest focus was put on making the device
out of as few parts as possible to decrease the final cost while simultaneously making it as
compact and small as possible.
Please refer to Appendix E for the AHP matrix [4] and other related design matrices; in the end
our design consideration criteria were the ease of gearing the system, how compact the entire
product was, its operating volume (in decibels), the total flow rate through the system, the total
cost, and how aesthetically pleasing the design was. In the end, the two top considerations were
the compactness of the design and the flow rate through the system with 30% and 35% of the
total weighting score, respectively.
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3. Concept Development
3.1 External Search
During our research, we came across many similar products that are currently on
the market. While these products may not all have the same function, they are all
powered by water turbines. The EcoPower Faucet, made by Toto, is a faucet that
uses a motion sensor to turn the faucet on. When the water is running, it first
passes through a reaction turbine and a generator that are stored underneath the
sink. The generator is housed in a separate compartment to separate it from the
water flow. The power generated is stored in rechargeable cells that are also
under the sink. This power is then used to power the motion sensor. These
faucets retailed for between about $900 up to $1900. [5]
Figure 2: EcoPower Faucet
Another similar product we found was the Sylvania LED Shower Light. This
product attaches to a shower head and uses the water flow to power a light.
The system is mounted before the actual shower head and contains a turbine
and generator. When the shower is turned on, the water first passes through
the turbine before it comes out of the shower head. This turbine is attached
to a generator and creates power for the light. [6]
Figure 3: Sylvania LED Shower Light
A third product which is not currently for sale yet is the HydroBee. This
product uses flowing water to charge batteries that are then used to
power a USB port. The water source is not only limited to household
faucets though, this device can be used in rivers or anywhere that there is
moving water. An advantage of this device is that
it is not limited to just one purpose, meaning it can be used to charge any
USB powered device. [7]
Figure 4: HydroBee
The design concepts that we generated all used one of three types of
turbines: Kaplan, Francis, or the Pelton wheel. All of these turbines have been around for a long
time, the most recent being the Kaplan Turbine which was developed in 1913. Due to the age of all
of these turbines, their patents have expired leaving us free to use the designs. For a detailed list of
researched patents, refer to Appendix C. All of the patents researched related to our product on an
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elementary basis and do not violate the more recent and complex patents. The closest ones also use
multiple inlet Pelton wheel designs, but all of the interfering patents have either expired or are
easily purchasable at this point in time.
3.2 Problem Decomposition
A block diagram of the system was implemented to
better visualize the total system process. Each step
is labeled with its inputs and outputs. Our defined
subsystems in our water turbine are the water,
turbine, gears, generator, and the application for
which our turbine is used. When following this
diagram in order and reading the inputs and
outputs, it becomes much easier to understand what
is actually happening. The water enters our device
and spins the turbine. That water then exits the
housing and is usable for the consumer. The
rotating turbine can be directly connected to the
Figure 5: System Block Diagram
generator or to gears that will increase the RPM
that is transmitted to the generator. The generator
will then produce a voltage that is measurable by a Digital Multimeter. The power produced by the
generator will then be used to charge the attached battery pack.
3.3 Concept Generation
The large number of ideas generated in the concept development phase was quickly
whittled down to four primary ideas using a sticky note selection method. Our first concept
used a Kaplan style reaction turbine with the generator situated next to the turbine: the plan
was to use the horizontal gap between the two axes for a belt, creating more vertical space
that our turbine could fill up. However, this concept directed the water stream over a
portion of the blades instead of utilizing all of the available area. [3]
Our second concept was a simple Pelton wheel, oriented such that the axis of rotation was
parallel to the ground. This was our simplest concept by far - the Pelton wheel turbine is a
tried and true design with a lot of available literature for further study. In the end the height
restriction would severely limit the size of the turbine and the lack of multiple inputs
would severely cut into the efficiency. [1]
The third concept used a Francis style reaction turbine, splitting the water stream at the
inlet and directing it into the blades perpendicular to the axial direction. This concept had a
compact design and seemed appropriate for the flow properties we expected, but it had a
very complex design and would require a completely sealed housing which would be
expensive to manufacture. [2]
The fourth concept used a Pelton wheel, much like the second, except oriented with the
axis of rotation perpendicular to the ground. Similar to the third concept, this one split the
water stream at the inlet and directed it into the blades on opposite sides of the central axis.
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This design did not need to be pressurized and saved space where our other Pelton wheel
concept could not. However, the possibility of stagnant water buildup in the bottom of the
housing meant this concept might not be as compact horizontally as the others. [1]
3.4 Concept Selection
Our four primary concepts were tested by running them through a series of screening
matrices. First, an un-weighted measurement matrix was made using the Kaplan Turbine as
a reference. Next, a Weighted Criteria Matrix was used to decide the importance of each
criterion relative to the other criteria. Finally, by combining these two matrices into a final
rating matrix, it was established that our two best designs were the Kaplan Turbine and the
Pelton Design with two inlets. After extensively reviewing both designs, it was decided that
the latter would become our proposed design. It provides high efficiency and is inexpensive
to manufacture due to its relatively simple design. The Kaplan design was not chosen
because of its difficulty meeting the height restriction and its increased complexity which
would drive up design and manufacturing costs. The decision matrices can be found in
Appendix F.
4. System Level Design
4.1 Modifications to Proposal Sections
When modifying our initial product proposal, several updates were made to the theoretical and
economic analysis sections. Updated nozzle analysis and efficiency calculations and graphs may be
found in section 4.4 while the new economic estimates may be found in section 4.9. Several
changes to the design were also implemented: we have greatly simplified the turbine design due to
efficiency and manufacturing tradeoffs, and the faucet attachment system has been changed to
incorporate less expensive parts and reduce the overall height of the final product.
Figure 6: Final Design
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4.2 Overall Description
The design (Figure 6) consists of five major systems: the
turbine housing, the generator housing, the turbine, the
generator, and the plumbing.
The turbine housing system includes the turbine housing
and the turbine lid. The separation of these two
components allows for easy assembly of the device. The
housing is designed to be sufficiently big enough to ensure
that water does not build up and slow down the turbine
while also remaining small enough to be aesthetically
pleasing and practical. The funnel shape of the housing is
designed to facilitate water flow to ensure that water does
not become stagnant at any point in the process. The
turbine housing lid is glued to the turbine housing. The
plumbing system is incorporated into the turbine
housing system. At the inlet, the device is attached to
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the sink via a swivel fitting to ensure that the generator housing does not interfere with
installation. The swivel fitting is connected directly to the inlet which is molded into the turbine
lid and turbine housing. From the inlet, the flow splits in two and is directed around the perimeter
of the device to transport water to the nozzles which direct the flow tangent to the outer radius of
the turbine. The nozzles are also directly molded into the turbine housing.
The generator housing is mounted on top of the turbine lid and is secured in place via glue and the
self-aligning feature of the turbine lid. The bottom compartment of the housing acts as the seal
between the turbine housing and the generator. The compartment is packed full with grease to
ensure that water cannot make its way up to the generator. The top compartment of the generator
housing contains the generator which is mounted via two M3 x 0.5 Hex Head Socket Bolts located
at the interface between the two compartments of the generator housing. The generator lid is glued
to the generator housing.
This device employs an impulse turbine which was designed to be simple in order to minimize
design cost and allow for injection molding. The turbine is given generous room within the turbine
housing to ensure that water does not become stagnant within its vicinity and decrease efficiency.
The turbine is press fit onto the metal shaft of the generator.
See Appendix G for additional views.
4.3 Detailed Drawings
An exploded view of the assembly can be seen
in Figure 7. The major dimensions of the
product are a height of 4.6875” and an overall
radius of 3.7”.
The height from inlet to outlet is 3.625” which
meets the target specification of 4” with
generous room to spare. Individual dimensioned
parts with all dimensions can be found in
Appendix G.
These parts include those that are not
Commercial Off The Shelf (COTS) parts, such
as the Generator Lid, Generator Housing,
Turbine Lid, Turbine, and Turbine Housing.
Figure 7: Exploded View
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4.4 Final Theoretical Analysis
To analyze the system, the independent variables need to be determined. The nozzle diameter,
turbine diameter, and generator to be selected are the three independent parameters which
determine the overall system performance. A conservation of energy analysis was performed to
relate the nozzle diameters to the inflow sink pressure and the nozzle flow rate. The resultant
equation is expressed below.
𝜋
2𝑃1
𝑣̇2 = 𝐷22 (
)
4
4𝐷24
𝜌𝛼 (1 − 4 )
𝐷1
Eq. 1: Conservation of Energy Derivation
Here, 𝑣̇2 is the volumetric flow rate from one of the outlets, 𝐷2 is the nozzle diameter, 𝐷1 is the
inlet diameter, 𝑃1 is the pressure in the sink, and 𝜌𝛼 is constant for this specific flow. Note that
position 1 is defined as before the flow enters the dividing “tee” junction and that position 2 is
defined at the outlet of the nozzle where the fluid experiences only atmospheric pressure. P1 is
therefore a gauge pressure and not an absolute pressure. From this equation, using a series of four
different nozzle diameters (ranging from an eighth to a half an inch) and the volumetric flow rate
and pressure data taken from the lab sink, a corresponding plot was created. (See Appendix I for all
analysis plots.) Here, the blue curve labeled “sink inflow” represents the pressure and volumetric
flow rate data we took from the lab sink, and the four other curves were generated from the
equation above. We can determine the operating volume flow rate of the different diameter nozzles
by finding the point at which these curves intersect with the sink inflow.
To determine the appropriate turbine diameter, a modified turbo-machine equation and efficiency
postulate were used in conjunction with one another. [8]
𝜔=
𝑣̇2
2𝑅𝐴𝑛
Eq. 2: Pelton Wheel Efficiency Postulate
Here, 𝜔 is the angular velocity of the turbine, R is the turbine radius and 𝐴𝑛 is the nozzle stream
cross-sectional area.
𝑇𝑠ℎ𝑎𝑓𝑡 = 𝜌𝑣̇(𝑟2 𝑣̇2,𝑡 − 𝑟1 𝑣̇1,𝑡 )
Eq. 3: Euler Turbo-Machine Equation
Here, 𝑇𝑠ℎ𝑎𝑓𝑡 is defined as the torque delivered by the turbine shaft, 𝑣̇ is the flow rate into the
turbine system, and r and v are the radius and velocity of the turbine at positions 1 and 2, defined at
different points along its diameter. From these equations, an equation expressing the maximum
possible shaft torque was derived:
𝑇𝑠ℎ𝑎𝑓𝑡,𝑚𝑎𝑥
𝑟𝑣̇2 2
= 𝜌
𝐴𝑛
Eq. 4: Maximum Shaft Torque Equation
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All variables maintain their earlier definitions. Using this equation, a corresponding plot was
created through the application of three different turbine diameters. To determine the final
unknown independent variable, several generators were tested and torque-angular velocity data was
derived from the results. All of this data has been represented graphically in Appendix I.
By overlaying the plots of different generators onto the turbine diameter data, the intersection
points could be determined and the operating angular velocities were found. (Note: these plots have
not been reproduced here; in total there are 15 possible combinations of these two plots and the
intersection calculations are trivial.) By working backwards from the derived generator efficiency
curves we were able to determine the most efficient generator, turbine diameter and nozzle
diameter combination that we could achieve with our available range of flow rates and pressures.
Some turbine and nozzle diameters could also be eliminated simply on the basis of mechanical
incompatibility or other physical constraints, but their data is presented here nonetheless. Because
of losses in the turbine due to instability and inaccuracies in efficiency calculations, we estimate
the total efficiency of our system at about 15%. With more precise equipment and technicians, the
turbine and the whole design could be much smaller and hold the water pressure more tightly,
allowing for a faster operational rotational speed. Based on the analysis, it was determined that the
turbine should be 1.5” in diameter, the nozzles should be 1/8” in diameter when using the 238473
generator.
4.5 Component and Material Selection Process for Mass Production
Our final product was designed to use only COTS and injection molded parts. Our water delivery
system is incorporated into the injection molded turbine lid and turbine housing. The swivel fitting,
used to attach the housing to the sink, is the only COTS part for the water delivery system. The
only other COTS parts used for the final product are the generator and two hex head bolts used to
secure it. The final product does not have to perform under extreme conditions of temperature,
pressure or applied stresses, so we were able to design for ease of manufacturing and low cost. The
turbine housing, turbine lid, generator housing, generator lid, and turbine will all be injection
molded out of plastic, allowing cost to be minimized and ease of manufacture to be maximized.
The injection molded plastics, which constitute the majority of the product, do not need to be
constrained by strength; therefore, they can be selected based on cost and their recyclability in
order to minimize the product’s impact on the environment. Since the injection molded pieces of
the product will be glued together, the product cannot be easily disassembled but the plastics can be
recycled. The COTS parts which will be implemented should be able to be reused in other
applications after the product is disposed of since they will not have undergone much wear and tear
during their lifetime.
4.6 Fabrication Processes for Mass Production
The final production version of the product will consist of 9 different parts, not including the
adhesive and grease. The turbine housing consists of the circular base that houses the turbine, the
cone, the output pipe thread, and the plumbing which includes the piping and nozzles. The entire
turbine housing would be injection molded so it would be one piece. The turbine lid, generator
housing, generator lid, and turbine will also be injection molded to ease in the manufacturing of the
product. All other parts are COTS parts which include the 3/8 -18 NPT Internal Pipe Thread Swivel
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Fitting, the Generator, and 2 M3x0.5x5.0 Hex Head Socket Bolts. These parts will be bought in
bulk to minimize cost. Assembly of the final product is easy and straightforward. To begin, the
generator will first be secured in the generator housing with the two bolts provided. The bottom
compartment of the generator housing will then be packed with grease to seal the generator. The
generator housing is then glued into place on the turbine lid and the turbine is press fit onto the
generator shaft. The turbine lid is then glued to the turbine housing and the generator lid is glued to
the generator housing after the generator is properly wired. The assembly process is then finished
by installing the swivel fitting. Loctite will be used to glue the injection molded housings and their
respective lids together. All components are designed to be self-aligning. The only tools needed are
an M3 Allen Wrench to install the bolts for the generator and a 5/8” wrench to install the swivel
fitting.
4.7 Industrial Design
The final production model is designed to be as sleek and smooth as possible in order to attract
customers. The turbine housing is by far the bulkiest of the design; however, it has been designed
with generous fillets and symmetry to give it smooth contours to increase its aesthetics. The
generator housing was also given a large fillet to continue our goal of achieving a smooth contour
to increase its appeal to customers. No tools will be needed to install the product to the sink, for it
comes with a swivel fitting to ensure easy installation of the product. It does not need to be
installed with a wrench because the swivel fitting contains an O-ring which doesn’t require much
force to seal. Therefore, it can be installed simply by the user’s hands, and due to its sleek and
cone-shaped design, it can easily be griped and installed by the user. The power switch is located
on the generator housing and only has two options: on and off. This makes it very easy for the
customer to use. The grease contained in the greasebox is water safe to ensure that it will not leak
out and harm any of the customers. A greasebox is used to ensure that water does not reach the
generator and affect its performance and lifetime. The product comes in a variety of colors
including red, orange, yellow, green, blue, purple, black, and white. The sleek and safe design of
this product along with its many color options will draw the attention of many potential customers.
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4.8 Economic Analysis
4.8.1 Unit Production Cost
Below is the BOM. The NPV analysis can be found in Appendix B.
4.8.2 Business Case Justification
From the NPV analysis shown in Appendix B, investing in this mini-hydroelectric generator is a
very profitable, with a very high return, if we sell at a price of $50 starting in year 2 our NPV by
the end of year four will be roughly 5 million dollars. This assumes that we are able to sell 100,000
units every year. For the analysis we included components that would be used in fabricating parts
and parts that were already premade that would be assembled to get the final component.
Overhead costs such as marketing and developing costs are only shown during the first year of the
NPV analysis since those costs are only incurred in the development of the product.
4.9 Safety
To ensure the safety and welfare of our consumers, our final product needed to meet the safety
regulations set by International Electrotechnical Commission (IEC). Such standards met include
IEC 60027 [9] standard, which govern the letter symbols used, our entire system for measuring
physical parameters such as output voltage and current to measurements of physical geometries
follow the SI system (The International System of Units ). The next criterion the IEC 60028 [10]
which governs the International Standard of resistance was also met. We use 12 AWG wire with a
max current output of 9.3 Amps which is more than enough for the apparatus[11]. This apparatus
also met the IEC-60062 [12] standard, as the resistors that will be embedded to help regulate the
current flow will use color codes prescribed by the standards. Though there are many UL standards
out there, there were two that were relevant to our product. The UL 1581 references standards for
electrical wires, cables , and flexible cords, which includes standard die cut sizes relevant to our
design, and it also complies with the enclosure for electrical equipment UL 50 which is intended to
be installed and used in non-hazardous locations like the water faucets. There are no relevant CPSC
standards for our particular design.
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Some potential failure methods that have been considered can be attributed to water leakage; such
problems can be solved using sealant to seal up the holes for the plastic tubes and the U-bolt that
enter the internal housing. Another safety concern was whether the system could be pressurized
without cracking, but initial testing allowed us to find that even at the weakest points where failing
could occur such as the sealing around the tubes, our design held just fine under the pressure. Last
but not least is the failing of the generator; this could be caused by a short from the electric wires
and/or wetting of the generator, which would increase the internal resistance. Proper insulation of
the wires and housing the generator can solve this problem.
4.10 Actual Construction Process of Final Prototype
The creation of the beta prototype was a five-week process. It began by cutting off a two inch long
piece of PVC piping with an inner diameter of 3 inches. This served as the housing for the turbine.
A funnel was then sanded down so it had a maximum diameter of three inches. The bottom spout
of the funnel was also sanded down and then a plastic 5/8 NPT external pipe thread was glued in its
place. The funnel was then press fit into the PVC pipe until it was ¼ inch from the bottom. Hot
glue was then used to seal the funnel in place. A Solidworks model of an impulse turbine was then
created with a 1.5-inch diameter. The model also had a ¼ inch hole in the center. A water jet was
used to cut the turbine out of 3/8 inch PVC. The PVC pipe then had a hole drilled on each side
offset ¾ inch from the center using a mill. Two holes were also drilled next to each other
perpendicularly relative to the last two holes that were drilled. A U-bolt was used in these holes to
mount a T-fitting. The vertical opening of the T-fitting had a brass male-male 5/8 NPT external
pipe thread screwed into it. The horizontal openings of the T both had brass hose connecting
fittings. Half inch external tubing was pushed onto each of the fittings. A small piece of 3/8 inch
external tubing was then pressed into the half-inch tubing. Then longer tubes with a ¼ inch outer
diameter were pressed into those tubes. Pipe clamps were used to make sure that the tubes stayed
together. Then a plastic rod with a diameter of ¼ inch was cut into two one-inch pieces. These
pieces were then placed in a lathe and had a 1/8-inch diameter hole drilled through them. They
were then press fit into the ¼ inch outer diameter tubes that were connected to the T-fitting. The
purpose of the rods was to act as nozzles for the tubing. These nozzles were then press fit into the
holes that were drilled into the housing earlier. Another one inch piece of that plastic rod was then
cut. This piece was also placed in a lathe, but this one had a .08-inch diameter hole drilled a ½ inch
into it. The side without the hole was then press fit into the turbine that was created earlier. Next,
the top of the housing was laser cut out of 1/8-inch acrylic. A hole was also laser cut out of the
center of the top to make room for the shaft. Then a two-inch piece and a ¼ inch piece of 1.5 inch
PVC pipe were cut. The ¼ inch piece was glued to the top piece of the housing so that its center
was right over the hole. Then a circle of 1.5-inch diameter was laser cut out of acrylic. A hole was
made in the center for the shaft and two holes were also made on either side of the center whole so
the generator could be mounted. The generator was then mounted to that piece of acrylic. Next, the
turbine with the plastic rod was put through the top acrylic piece of the housing. The generator was
then press fit into the .08-inch diameter hole on the other side of the plastic rod. That ¼ inch PVC
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pipe was then filled with grease to act as a sealant for the acrylic that the generator was then
mounted to. Wires were then soldered to the leads of the generator and then the two-inch piece of
PVC pipe was glued to the acrylic so that the generator was inside of it. Another 1.5-inch diameter
piece of acrylic was then cut with two holes in it where the switch and barrel adapter were
mounted. They were then wired in series with the generator and the acrylic was then glued to the
top of the PVC. Everything was then sealed with hot glue and the prototype was complete.
5. Testing
5.1 Test Procedure and Plan
Our beta prototype did not meet all of the specifications for our final product. Despite this, much
was learned through extensive testing and simple observation of its operation. Before testing our
prototype, it was observed that the generator extended too far away from the housing and prevented
the device from being attached to the sink. After temporarily solving this problem by modifying the
sink’s attached pressure gauge setup, we began our first real test, which proceeded as follows:
Initially we attached the prototype to the laboratory sink underneath the pressure gauge and ran it at
about 40 psi; a very slow initial flow rate. The turbine began to spin after overcoming the initial
frictional kinetic energy barrier and a peak voltage slightly less than one volt was achieved. The
turbine housing did not fill up completely with water, and the outflow rate was essentially the same
as the inflow rate. From this point, we slowly turned the water pressure down by opening the valve,
allowing higher and higher flow rates to enter the system, observing the apparent rotational
velocity and noting the peak voltage output. Until we reached about 10-15 psi (a nearly completely
opened faucet at full throttle) the turbine housing did not completely fill up – gradually water
began to collect in the funnel underneath the actual turbine, but the turbine itself was unaffected.
When we completely opened the faucet tap and disengaged the pressure gauge (0 psi), the turbine
compartment completed flooded. Our lid was attached with screws and no true sealant was used in
any part of the prototype, so water began spraying out of the top of the prototype very quickly after
turning on the faucet. Since this “pressure relief area” was unsealed and not even glued to the rest
of the housing, all other glued and attached components remained leak free. These operating
conditions resulted in a peak voltage of about 1.9 volts with a steady state output of about 1.1 volts.
In its current condition, not much more can be learned from the prototype. Modifications must be
made to seal the turbine chamber, and after similar small unforeseen problems are taken care of
(such as the height problem) we can proceed with analytical testing.
To obtain the maximum amount of helpful and accurate data from our prototype through its testing,
the prototype planning methods outlined in Ulrich and Egginger’s Product Design and
Development text will be implemented [4]. The first step in this process is to define the purpose of
our prototype. Our prototype has been designed to test some basic aspects of the final product by
fulfilling the majority of its design specifications. The stated purpose is to determine an optimal
combination of turbine diameter, nozzle diameter and generator while observing small, simple,
unforeseen issues such as the flooding of the turbine chamber or leakage. Next the prototype’s
level of approximation must be assessed. Since our prototype and final product did not need to be
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optimized for harsh operating environments or conditions, the material selection and ease of
manufacturing did not need to be considered when the beta prototype was constructed. We utilized
simple materials and methods of manufacture to fabricate our prototype. However, the specific
dimensions of the turbine itself as well as the nozzles and sealed chamber were all necessary to
adequately gather data. Thirdly an experimental plan needed to be outlined.
The equipment needed to carry out the testing procedures include a bucket with a known or
measureable volume, a stopwatch, a digital multimeter, a resistor and wiring, a pressure gauge, and
a laboratory sink capable of meeting the standard pressure and volume flow rates from a typical
kitchen sink. By procuring multiple nozzle diameters and turbine diameters and holding the
generator constant, we will test the results of our analysis to ensure that we have truly chosen the
most efficient combination of the three independent design variables. Due to expense, additional
generators were not vital to further experimentation but could have been added to increase the
number of experiments necessary. Running the device at different pressures will allow us to
gradually narrow down the optimal operating pressure. The outflow rate will be measured with the
bucket and stopwatch, the pressure would be set with the attached pressure gauge, and the output
voltage willbe measured with the multimeter and resistor. Finally a schedule for procurement,
construction and testing needed to be established. Our beta prototype was completed on 4/2/14,
with procurement of materials and construction beginning on 3/31/14. Our testing officially
concluded on 4/21/14 when the final prototype was completed and presented.
5.2 Test Results and Discussion of Results
The final prototype was tested according to the procedure outlined above. Flow rate and pressure
data were obtained from the test, and can be found plotted in Appendix I. In the end, our peak
voltage output was 1.8 volts, higher than our stated metric of 1.5 volts. Our maximum voltage
output occurred at the minimum induced pressure on the inflowing water at the maximum flow
rate, meaning that the energy stored in the inflow was approximately 18 watts. Given that our
voltage was recorded over a 10 ohm resistor, our power out is equal to approximately 0.324 watts,
netting us an efficiency of 1.8%. (Further efficiency plots may be found in Appendix I). This falls
short of the initial estimate of 15% efficiency; these losses can be attributed to problems with the
generator resisting rotational motion during testing and vortices created in the exit funnel of the
turbine chamber. The nozzles and turbine were not tested as independent variables for this round of
testing because of the difficulties with reconstructing the final prototype accurately had these
components been replaced.
6. Conclusion and Recommendation
By researching and surveying potential customers, it was determined that the top needs that the
device must meet is low cost, small size, be aesthetically pleasing, and safe to use. The final design
concept that was chosen meets all of these requirements. When creating the alpha and beta
prototype, these specifications were kept in mind. The beta prototype created has a unique design
the appeals to the consumer. While the prototype is wide, it is still smaller than the 4 inch input to
output specification that was given. Many parts are off the shelf and can be bought in bulk, which
will decrease the price of production thus making the retail price less expensive. The design
employs a historically proven two nozzle impulse turbine with a $35 per unit cost which leaves
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room for a large profit margin of $15 per unit. This device is unique because its purpose is to
charge rechargeable batteries. Throughout the researching and benchmarking phase of designing
this turbine, there were no products found that are currently on the market that have this same
function. This creates an untapped marked that will intrigue the customers, which could make this
product very successful. Compared to similar products currently on the market, our turbine is
quieter and functions at similar efficiencies when operated under different applied water pressures.
In future iterations of the product, we hope to improve its performance dramatically by changing
the outlet configuration to provide less turbulent outflow and increase the total efficiency by
changing the internal pressure. We feel as though the aesthetics of the current product are
sufficiently attractive, and will preserve that image as we proceed in development. Reducing the
overall diameter would be possible with higher tolerance parts and machining capabilities would
reduce the overall size and cost of the product, and is something we can experiment with moving
forward.
Working on this turbine taught us a lot about the design process in general as we learned about the
intricacies of water turbine design. Our team worked well together, and even though there were
some stressful moments the overall experience was positive. We learned a lot about the details of
writing effective reports and keeping our notes and data up to date at all times. We also found that
keeping track of every little detail when we machined the parts proved invaluable later on.
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7. References
[1] "Pelton Wheel." Princeton University. N.p., n.d. Web. 03 Mar. 2014.
http://www.princeton.edu/~achaney/tmve/wiki100k/docs/Pelton_wheel.html
[2] “Lowell Notes: James B. Francis.” U.S. Department of the Interior. N.p., n.d. PDF. 03 Mar.
2014. http://www.nps.gov/lowe/historyculture/upload/JB%20Francis_%20Lowell%20Notes.pdf
[3] “Hydropower project Tocoma.” IMPSA. N.p., n.d. PDF. 03 Mar. 2014.
http://www.impsa.com/en/downloads/HYDRO/TOCOMA.pdf
[4] Ulrich, Karl T., and Steven D. Eppinger. Product Design and Development. New York:
McGraw-Hill, 1995. Print.
[5] EcoPower Faucet. Diagram. n.d. Web. 03 Mar. 2014.
http://www.totousa.com/Green/Products/EcoPowerFaucets.aspx
[6] Sylvania LED Shower Light. n.d. Web. 03 Mar. 2014.
http://www.techmall.com/v/vspfiles/photos/57919-6.jpg
[7] Hydro Bee. n.d. Web. 03 Mar. 2014.
http://www.xconomy.com/wordpress/wp-content/images/2013/11/Hydrobee-model.jpg
[8] “Fluid Mechanics: Fundamentals and Applications.” Cengel, Yunus A., and John M. Cimbala.
Boston: McGraw-Hill Higher Education, 2010. Print.
[9] “Letter symbols to be used in electrical technology,” IEC 60027, 1977
[10] American Wire Gauge (AWG) Sizes and Current Limits,” Web. 02 May 2014
http://www.keywolf.com/American_Wire_Gauge.php
[11] “International standard of resistance for copper,” IEC 60028, 1977
[12] “Marking codes for resistors and capacitors,” IEC 60062, 1977
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8. Appendices
Appendix A: Project Management
Breakdown of individual skills:
Michael George
Strengths: Technical writing and sketch mock ups
Areas for Improvement: Solidworks and manufacturing experience
Dylan Heimbach
Strengths: SolidWorks Modeling and Machining
Areas for Improvement: Technical Writing
Thomas Tiarks
Strengths: Machining and CAD experience
Areas for Improvement: Technical writing
Basil Odulukwe
Strengths: Machining and Electrical Engineering experience
Areas for Improvement: CAD experience
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Appendix B: NPV Analysis
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Appendix C: Patent Search
Power generating water turbine: US 4076448 A (Pub. Feb 28, 1978)
This power generating water turbine has two turbines mounted vertically on the same shaft. The
water input is split into multiple channels, which allows the water to be directed and hit the
turbines in multiple spots. This turbine is designed for use in streams with a slow moving current.
Water turbine-wheel: US 1065208 A (Pub. Jun 17, 1913)
This water turbine-wheel uses a horizontally mounted helical turbine. This design allows the
turbine to use all of the force that comes from the water. It is designed for high head usage but can
be modified for either high or low pressure.
Bidirectional water turbine: US 8596956 B2 (Pub. Dec 3, 2013)
This bidirectional water turbine has an upstream rotor and a downstream rotor. The blades rotate in
the opposite directions of each other. This turbine is designed for use in a tidal barge. The turbine is
rotated by the tidal current.
Water turbine with water circulation: EP 2166221 A3 (Pub. Feb 20, 2013)
This water turbine uses a paddle wheel design. It is rotated by water in a channel and by water from
a high-pressured water jet that comes from a pressurized pump that hits the paddles head on. The
water is released back into the channel on the opposite side of the paddle wheel.
Multi-nozzle impact-type water turbine base: CN 203098127 U (Pub. Jul 31, 2013)
This multi-nozzle water turbine uses a Pelton wheel. Water hits the turbine at multiple points from
nozzles that speed up the flow of the water. The nozzles are able to be adjusted so they can hit the
turbine in the appropriate spot to generate the most power. This design is similar to ours because
our design uses two inlets that are nozzled down.
Low-head impulse water turbine set for hydroelectric generation: CN 101915195 A (Pub. Dec
15, 2010)
This turbine is designed to be used at a low head, approximately 10~100 m. It uses an impulse
turbine, specifically a Pelton turbine. The low-head design allows the turbine to efficiently use the
wide domain. The back of the housing is open so the water can freely exit.
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Appendix D: Customer Needs Survey
Customer Survey
Rank the following features on a scale from 1 to 7, 1 being the most important and 7 being the
least important.
Device is small / does not obstruct sink space
Device is quiet
Device is aesthetically pleasing
Device does not affect water speed
Device is easy to use
Device is inexpensive
Device is portable
What can you see yourself using this device for in your house?
Would you be inclined to purchase this device if it could function as a light source for your sink
area? Why or why not?
Would you be inclined to purchase this device if it could recharge your batteries? Why or why
not?
Would you be inclined to purchase this device if could act as a USB power source? Why or why
not?
Would you be inclined to purchase this device if it attached to a shower head to show how hot or
cold the water was? Why or why not?
How often do you see yourself using this product?
Would you recommend this product to your friends or family? Why or why not?
Do you already use a product that attaches to your sink faucet, such as a water filtering device? If
so, what do you like about this device? What are some potential flaws with this device
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Appendix E: QFD Matrix and Customer Needs AHP Matrix
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Appendix F: Concept Screening and Weighted Matrices
Cost
Size
Portability
Easy to Use
Flow Rate
Aesthetics
Noise
Total
Rank
Criteria
Weight
Cost
20%
Size
25%
Portability
5%
Easy to
Use
5%
Flow Rate
10%
Aesthetics
20%
Noise
15%
Total Score
Rank
Kaplan
Impulse: 1
Nozzle
0
0
0
0
0
0
0
0
+
0
+
+
0
Impulse: 2
Nozzles
Francis
+
+
0
+
+
+
4
1
Table 3: Concept Screening Matrix
0
+
0
0
0
0
0
Kap
Impulse: 1
Impulse: 2
Franci
llanl
Nozzle Score Rating
Nozzle Score Rating s Score
Rating
Score Rating
3 an 0.6
4
0.8
4
0.8
2
0.4
3
0.75
3
0.75
4
1
3
0.75
3
0.15
3
0.15
3
0.15
3
0.15
3
3
3
3
0.15
0.3
0.6
0.45
3
2
3
3
2
2
0.15
0.3
0.4
0.3
2.85
4
4
4
2
3.65
1
0.2
0.4
0.8
0.3
3
3
2
3
0.15
0.3
0.4
0.45
2.6
Table 4:
Weighted
Matrix
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Figure 8: AHP Matrix
Figure 9: Concept Screening Matrix
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Appendix G: Additional Drawings
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Appendix H: Gantt Chart
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Appendix I: Analysis Plots
Figure 10: Overlaid Pressure vs. Volume Flow Rate Plot
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Figure 11: Turbine Analysis: Output Torque vs. Angular Velocity
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Figure 12: Generator Analysis: Input Torque vs. Angular Velocity
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Figure 13: Generator Analysis: Efficiency Diagram
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Figure 14: Final Prototype Pressure vs. Volumetric Flow Rate Plot
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Figure 15: Final Prototype Efficiency Plot
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Appendix J: Attestation of Work
Michael George:
I attest that I have contributed primarily to sections 1.2, 1.3, 2.2, 3.3, 4.1, 4.4, 4.5, 5.1, 5.2 and
parts of section 6 in this document, including the references and sketches contained therein. I
conducted turbine research both early on in the semester and recently in order to contribute to the
“background information” section. I completed the entirety of the analysis on my own,
developing all of the equations and plots presented. I created the majority of the Appendices
(with secondary help from Thomas Tiarks).
Dylan Heimbach:
My responsibilities within this design report include sections 4.2, 4.3, and the BOM information
for 4.8.1. I did all the SolidWorks models and drawings found within the document. I also
contributed to other sections during the design process such as obtaining customer needs and
performing matrices.
Thomas Tiarks:
I have contributed sections 3.1, 3.2, 3.4, 4.6, 4.7, 4.9 and parts of section 6 to this document. This
includes doing external research, including the patent research seen in the appendix, creating a
block diagram, and summarizing our document in the conclusion. I was involved in creating the
decision matrices that were used to select the final design concept. I also assisted Michael
George in the creation of the Appendices.
Basil Odulukwe:
My responsibilities for this proposal include sections 1.1, 2.1, 4.8.1, 4.8.2, and 4.9 on this
document. This includes conducting the problem statement, customer needs and specifications,
economic analysis which includes the fabrication and quantitative components of the BOM,
safety analysis with relevant IEC standards, and contributed to some of the information seen on
the Appendices. I was involved in the design of the QFD chart, and created the NPV chart. I was
also in charge of conducting the surveys and provided key preliminary economic analysis and
complete economic analysis to ensure the economic vitality of our product.
All team members were involved in proofreading, group editing and formatting the final
document.
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