6-Stroke
Project Proposal and Feasibility Study
11 December 2009
Team 14
John Mantel
Andrew DeJong
Tim Opperwall
Marc Eberlein
Jim VanLeeuwen
1
Executive Summary
Fossil fuels are being used at an alarming rate and unconventional methods need to be
considered to help reduce the dependence on these fuels. The goal of this project is to
increase the efficiency of a standard internal combustion engine. This will effectively
reduce fuel consumption, and therefore emissions, without significantly compromising on
power. To accomplish this, a four stroke engine will be modified to a six stroke engine
by adding a steam cycle, such that the engine (1) intakes, (2) compresses, (3) combusts,
(4) recompresses, (5) injects water, (6) exhausts.
The project is split up into three major subcomponents.
 The injection system will be designed and implemented to be able to inject a
precise amount of water at a specific time. An electronic engine control unit
(ECU) will adjust the amount of water injected based on the temperature of the
engine. If the engine is running too hot, more water will be injected.
 The current camshaft and valves will be removed. The ECU will use a crankshaft
position sensor to monitor the engine’s rotation and control the timing on
overhead electronic valves.
 Calculations and experiments will determine the amount of water to inject per
cycle and the relative efficiency of the engine. Power and fuel consumption tests
will be conducted before and after the modification to verify these calculations.
The budget for this project is projected to be approximately $825. However, this is offset
by purchasing the water injection control system through a project in ENGR 315.
Consequently the effective budget for ENGR 339 is $675.
This semester long feasibility study determined the above ECU method as a feasible
project and will be implemented in Engineering 340 to achieve the design goals.
2
Table of Contents
Table of Contents .......................................................................................................................................... 2
1. Introduction ........................................................................................... Error! Bookmark not defined.
1.1
Team Profile .................................................................................................................................. 4
1.1.1.
Tim Opperwall ....................................................................................................................... 4
1.1.2.
Andrew DeJong ..................................................................................................................... 4
1.1.3.
John Mantel .......................................................................................................................... 4
1.1.4.
Jim VanLeeuwen ................................................................................................................... 4
1.1.5.
Marc Eberlein ........................................................................................................................ 4
1.2
Project Motivation ........................................................................................................................ 5
1.3
Project Description........................................................................................................................ 5
2. Project Objectives ................................................................................................................................. 5
2.1
Design Objectives .......................................................................................................................... 5
2.2
Design Norms ................................................................................................................................ 5
2.2.1.
Transparency and Integrity ................................................................................................... 5
2.2.2.
Stewardship .......................................................................................................................... 6
3. History and Research ............................................................................................................................ 6
3.1
Existing Patents ............................................................................................................................. 6
3.1.1.
US Patent 1339176 – May 4, 1920........................................................................................ 6
3.1.2.
US Patent 3964263 – June 22, 1976 ..................................................................................... 6
3.1.3.
US Patent 4736715 – April 12, 1988 ..................................................................................... 6
3.1.4.
US Patent 6253745 – June 3, 2001 ....................................................................................... 6
3.1.5.
US Patent 6311651 – November 6, 2001 .............................................................................. 6
3.2
Recent Work ................................................................................................................................. 6
3.2.1.
Bruce Crower’s Engine .......................................................................................................... 6
4. Testing ................................................................................................................................................... 7
4.1
Dynamometer Testing .................................................................................................................. 7
4.2
Emissions Testing .......................................................................................................................... 7
4.2.1.
Orsat Testing ......................................................................................................................... 7
4.2.2.
Gas Chromatography ............................................................................................................ 8
4.3
Fuel Consumption ......................................................................................................................... 8
5. Thermodynamic Analysis ...................................................................................................................... 8
6. Water Injection System ....................................................................................................................... 10
7. Design Alternatives ............................................................................................................................. 12
7.1
Design A: Camshaft Design ......................................................................................................... 12
7.2
Design B: Electronic Control System ........................................................................................... 14
7.3
Budget Analysis ........................................................................................................................... 16
7.4
Decision Matrix ........................................................................................................................... 16
8. Project Management .......................................................................................................................... 17
8.1
Task Delegations ......................................................................................................................... 17
8.1.1.
Controls ............................................................................................................................... 17
3
8.1.2.
Thermodynamics................................................................................................................. 17
8.1.3.
Cam Analysis ....................................................................................................................... 17
8.1.4.
Testing ................................................................................................................................. 17
8.1.5.
Inventor modeling............................................................................................................... 18
8.1.6.
Website ............................................................................................................................... 18
9. Conclusion ........................................................................................................................................... 18
10.
Special Thanks ................................................................................................................................. 19
10.1 Ren Tubergen .............................................................................................................................. 19
10.2 Ned Nielsen ................................................................................................................................. 19
10.3 Nick Hendriksma ......................................................................................................................... 19
10.4 Paulo Ribeiro ............................................................................................................................... 19
10.5 David Benson .............................................................................................................................. 19
10.6 Gary Geukes ................................................................................................................................ 19
11.
Appendix A ......................................................................................... Error! Bookmark not defined.
12.
References ...................................................................................................................................... 24
4
1.
Team Introduction
From left: Tim Opperwall, John Mantel, Andrew DeJong, Marc Eberlein, and Jim VanLeeuwen.
1.1
Team Profile
1.1.1. Tim Opperwall
Timothy Opperwall is from Grandville, Michigan and will be graduating with a
Bachelors degree in Engineering with a mechanical concentration. He is looking into
Mid-West graduate programs as well as employment in the West Michigan area.
1.1.2. John Mantel
John Mantel is from Chelsea, Michigan and will be graduating with a Bachelors degree in
Engineering with a mechanical concentration. He is pursuing professional basketball
opportunities in Europe but has plans to return to the engineering field in the future.
1.1.3. Andrew DeJong
Andrew DeJong is from Grand Rapids, Michigan and will be graduating with a Bachelors
degree in Engineering with a mechanical concentration. He is pursuing graduate school in
the Washington, D.C. area.
1.1.4. Marc Eberlein
Marc Eberlein is from Jamestown Township, Michigan and will be graduating with a
Bachelors degree in Engineering with a mechanical concentration. He is currently
employed at Highlight Industries and hopes to continue working there full time after
graduation.
1.1.5. Jim VanLeeuwen
5
Jim VanLeeuwen is from Jenison, Michigan and will be graduating with a Bachelors
degree in Engineering with a mechanical concentration. He is actively seeking full time
employment opportunities in both manufacturing and design.
2.
Project Introduction
2.1
Project Motivation
The modern world is driven by fossil fuels. Consequently, society has been consuming
exhaustible resources at an ever increasing rate. There are many possible long term
solutions including nuclear, hydroelectric, solar and geothermal energy sources.
However, these solutions cannot be realistically implemented quickly and effectively. In
the short term, unconventional and hybrid solutions must be implemented to reduce the
consumption of fossil fuels and provide more valuable time for the long term solutions to
be implemented. The goal of this project is to increase the efficiency of a standard
internal combustion engine. This will effectively reduce fuel consumption, and therefore
emissions, without compromising on power.
Project Description
To further the research in short-term, unconventional solutions, a one cylinder, fourcycle, 16-horsepower, internal combustion engine will be modified with the goal of
higher efficiency. The modified engine will run six cycles by adding a water injection
and an exhaust cycle to the end of the traditional four cycles. The first four strokes will be
an intake, compression, combustion, and exhaust identical to the original engine. In the
fifth stroke, water will be injected into the hot cylinder and will expand into steam. In the
sixth stroke, the steam and leftover combustion gases will be exhausted. The modified
engine will be more efficient because the fifth stroke is a second power stroke that uses
heat otherwise lost to the atmosphere.
2.2
3.
Project Objectives
3.1
Design Objectives
The main objective for this project is a working six-stroke internal combustion engine.
The desired outcome is to observe decreased fuel consumption for the same power
output. Along the way, a number of intermediate goals will be set to track progress and
analyze risks. The specifics of these goals are further discussed in the Camshaft Design
and Electrical Control System sections.
Design Norms
As Christian engineers, this team needs to consider more than just time and money in the
decision making process. Design norms, such as transparency, integrity, and stewardship
will be included in every decision.
3.2.1. Transparency and Integrity
3.2
6
This project is part of larger research with the goal of greater efficiency. Withholding
data and calculations, or reporting falsified or incomplete data, is not conducive to
advancing research. Researchers and users of this technology need to know that it will
work. Consequently, a large part of this project will be thoroughly documenting all the
calculations and modifications. All our progress and data will be documented and made
public.
3.2.2. Stewardship
It is the responsibility of all Christians (including Calvin College, its students, and this
team) to use natural resources in way that honors God. The way fuels are currently used
can be improved to better protect resources. Increasing fuel efficiency is one way the
team can respond to this calling.
4.
History and Research
4.1
Existing Patents
4.1.1. US Patent 1339176 – May 4, 1920
Leonard H Dyer patented the basic idea of using a water injecting fifth stroke to increase
efficiency and simplify the cooling of an internal combustion engine.1
4.1.2. US Patent 3964263 – June 22, 1976
Robert C Tibbs expanded on Dyer’s patent to include a piston with a higher heat capacity
and an exhaust system that condenses and filters the water after it is exhausted from the
cylinder.2
4.1.3. US Patent 4736715 – April 12, 1988
Gregory J. Larsen patented a 6-stroke engine that supercharges and reheats the intake air.
The two intake ports for the cylinder are cam actuated. 3
4.1.4. US Patent 6253745 – June 3, 2001
US Patent 6311651 – David M Prater patented a six stroke engine that contains the combustion
products in a separate heat regenerator, injects water into the regenerator, and then opens the
regenerator to the cylinder, providing another power stroke.4
4.1.5. US Patent 6311651 – November 6, 2001
Satnarine Singh patented a six stroke engine with a computer controlled water injection
system. The patent calls for a turbine that removes additional energy from the exhaust
steam and a condenser that recycles the used water.5
4.2
Recent Work
4.2.1. Bruce Crower’s Engine
7
Bruce Crower, owner of Crower Cams and Equipment Company, modified a four-stroke
diesel engine to run a six-stroke cycle similar to the one proposed in this project. His ran
for over an hour and was only warm to the touch.6 Crower was not available for comment
due to medical issues.
5.
Testing
5.1
Dynamometer Testing
To determine if power is maintained, increased, or reduced, testing of the engine will be
conducted on the unmodified and modified engine cycles. This testing aids in
determining the level of success of the project.
In an attempt to do preliminary testing of the unmodified engine, the group contacted
Gary Geukes at Fastbikes USA, a local business that was willing to test the engine on its
motorcycle dynamometer. To test the engine, the team attached a small tire to the engine
and built a frame to hold the engine steady during the testing.
Unfortunately, since this dynamometer was designed for high-power motorcycle engines,
the unmodified engine was unable to provide enough torque to spin the dynamometer at a
speed high enough to prevent stalling. Consequently, the unmodified engine stalled every
time it contacted the dynamometer.
Ren Tubergen, the industrial consultant for this project, provided contact information for
John Farris in the Grand Valley State University engineering department. Mr. Farris has
access to a small engine dynamometer used to test engines in the Baja. Mr. Farris has not
responded to the team’s attempts to contact him.
At this time, attempts to test the unmodified engine have been placed on hold to allow
other areas of the project to continue moving forward.
5.2
Emissions Testing
To analyze the efficiency of combustion in the engine, the concentrations of the
combustion products in the exhaust gases must be determined. The two methods
explored to accomplish this were Orsat testing and gas chromatography.
5.2.1. Orsat Testing
In Orsat testing, the exhaust gasses are piped through separate containers filled with
different solutions (potassium hydroxide, pyrogallol, etc). As the gasses pass through the
solutions, specific combustion products (carbon monoxide, oxygen, etc) are absorbed into
the solutions, reducing the volume of the emission gases.7 From this we can calculate the
composition of the emission gases. Professor Sykes suggested that Materials Testing
Consultants might be able to conduct an Orsat test on the unmodified engine. However,
they do not have the facilities for this type of test. Research into other possible venues for
this test has been unsuccessful.
8
5.2.2. Gas Chromatography
After contacting Calvin’s chemistry department, Professor David Benson has suggested
that gas chromatography could be used to analyze the exhaust gases. He was also
optimistic that this test could be performed using Calvin’s existing equipment. Gas
chromatography passes the exhaust gases through a capillary tube containing a silicone
solid. As the gases are forced through the solid, the components separate out in a
predictable order. Gas chromatography is most often used for environmental monitoring
and industrial chemical fields.8,9,10
5.3
Fuel Consumption
To determine the change in fuel consumption, tests will be run before and after the engine
modifications. These tests will observe the amount of fuel consumed to achieve a certain
amount of work. A likely way to do this would be to drive a water pump to move water
from one place to another. This would require a quantifiable amount of work and the
power could be controlled by a valve on the water flow. Another way would be to simply
measure the fuel consumption at a known power during the dynamometer testing.
6.
Thermodynamic Analysis
Each of the six stages of the six-stroke operation will be broken down into
thermodynamic states to find critical unknowns in the design process. These occur after
each of the six strokes. Because the engine is an open system, the thermodynamic state
before the intake must be examined to take into account atmospheric conditions. So there
are seven thermodynamic states to be examined.
These thermodynamic calculations will determine the amount of water injected during
the fifth stroke. The appropriate heat reduction and steam content are crucial variables.
Having the correct amount of water injected into the system will insure that the right
amount of heat is removed by turning the water into steam. This sudden expansion
provides additional power.
For the thermodynamic state directly before intake, atmospheric conditions are assumed
(22 °C and 101 kPa). This defines the first thermodynamic state.
Directly after intake, the pressure is assumed to still be atmospheric. The volume of the
air will be determined from the dimensions of the cylinder. The amount of gasoline in the
cylinder will be determined by the fuel consumption test. By measuring fuel consumption
over a specific amount of time over a constant, known, drive shaft speed the fuel
consumption per cycle will be calculated. This defines the second thermodynamic state.
9
For the third thermodynamic state, after compression, three variables are known: the
volume and pressure of the air in the cylinder, and the mass of the gasoline in the
cylinder. The volume and pressure will be calculated assuming ideal gas properties and
using the compression ratio for the cylinder. The mass of gasoline used was known after
the second thermodynamic state and this amount will not have changed with
compression. The variable that will be unknown is the temperature of the air inside the
cylinder. The proposed method for finding this temperature is to place two thermocouples
in the head at known distances from the inside face of the cylinder. Since there will be a
linear regression from the temperature inside the cylinder to the temperature of the
outside air, the two known temperatures will be calibrated to find the unknown
temperature inside the cylinder. This defines the third thermodynamic state.
The fourth thermodynamic state is the expansion of the cylinder due to combustion. For
this state, the known variables are the composition of combustion products from the
exhaust gas test, and the volume of the products. The exhaust gas test will measure the
composition of the combustion products and how much fuel was actually ignited in the
engine. From this information, the mass of fuel used, and therefore, heat added to the
engine will be determined. The two thermocouples method will be used to find the
temperature inside the cylinder. This defines the fourth thermodynamic state.
The fifth thermodynamic state is after the first exhaust stage. The combustion products
could either be exhausted to the atmosphere or recompressed to retain additional heat.
However, recompressing the products would be a loss of work and could cause the
engine to stall, especially during start up. Additionally, recompressed products would
result in a high cylinder pressure which would require the water injection pressure to be
extremely high. Higher injection pressures require a larger pump and present greater
safety risks. Consequently, the combustion products will be exhausted to a heat
exchanger that will pre-heat the water before injection. This retains the heat inside the
cycle without reducing power. The temperature will be measured by a thermocouple in
the exhaust stream. The composition of the gas remaining the cylinder is known from the
exhaust gas test. This defines the fifth thermodynamic state.
The sixth thermodynamic state is after the water injection. A small amount of water is
injected into the cylinder which lowers the engine operating temperature by making
steam. This sudden expansion drives the piston down and provides power for the crank
shaft. The temperature of the injected water will be measured with a thermocouple. The
amount of water is determined by the water injection control unit such that the water
removes just enough heat to maintain the optimal operating temperature. The temperature
of the steam will be determined by the two thermocouple method. This defines the sixth
thermodynamic state.
10
The seventh thermodynamic state is after the final exhaust. The pressure and temperature
of the surrounding atmosphere are the known variables. The composition is again known
from the exhaust gas tests. This defines the seventh thermodynamic state. The full
thermodynamic calculations so far can be seen in Appendix A
The most important part of this energy balance analysis is the power output by the
driveshaft. The desired outcome of this project is to increase the amount of power output
per gasoline consumed.
7.
Water Injection System
To inject the water during the 5th stroke, a water injection system will be installed to the
head of the cylinder. The proposed system will pump water from an open water tank to a
solenoid triggered fuel injector positioned on the head of the engine. For the final
prototype, it would be best if the amount of water injected could be adjusted to maintain
an optimum engine temperature. To do this, a control system was designed by Tim
Opperwall and Andrew DeJong in Engineering 315 during the 2009 fall semester. This
proposed system is diagramed in Figure 1. The controller is a flexible, open-source
prototyping board made by Arduino, shown in Figure 2. The board is programmed using
a C based computer language and transforms the resistance of a thermocouple located on
the engine into a variable power supply to the pump. As the engine heats, the controller
increases the power to the pump, which forces more water into the engine every cycle to
cool the engine. This design will be used to set and maintain an optimal operating
temperature in the engine cylinder.
11
Figure 1: Proposed water injection system.
Figure 2. The Arduino prototype board.
12
Preliminary experimenting has been conducted to determine the unmodified engine’s
normal operating temperature. For the purpose of the controller, the operating
temperature of the engine can be represented by an exterior temperature. Figure 3 shows
exterior temperature of the unmodified engine during a warm start. The temperature
converges to 105°C which will be calibrated to the internal temperature. A desired
temperature will be chosen based on thermodynamic calculations. Then the controller
will be programmed to begin injecting water into the cylinder when the engine
temperature reaches the desired temperature. The amount of water injected will slowly be
adjusted to maintain an equilibrium at the desired temperature.
120
Temperature (*C)
100
80
Exterior Engine Temp
60
Ambient Temperature
Desired Ext Temp
40
20
0
0
20
40
60
Time (s)
80
100
120
Figure 3: Preliminary Engine Temperature Data.
8.
8.1
Design Alternatives
Based on research and professional advice, there are two main alternatives being
considered.
Design A: Camshaft Design
The first option, Design A, utilizes a mechanical control of the engine cycles. The engine
will need a new camshaft that is geared to turn one revolution every three revolutions of
the crankshaft instead of the current speed of one revolution every two revolutions of the
crankshaft. Being a pushrod engine, the camshaft is geared directly to the crankshaft.
This makes it impossible to change the number of teeth on each shaft to achieve the
correct speed due to size issues. Because of this, a third shaft will be installed and a
double reduction gearing system will be used. This is shown in Figure 4.
13
Crankshaft
Camshaft
Reduction Shaft
Figure 4: Reduction gearing for camshaft.
The existing cam design consists of a 29 tooth beveled gear on the crankshaft mating to a
58 tooth beveled gear on the camshaft. The proposed design will remove the existing
gears and use straight-toothed gears on all three shafts. The reduction ratio at each shaft
has not been determined yet, but will be close to a 29-58 tooth pair of gears for a 1:2
reduction between the crankshaft and the reduction shaft and 20-30 tooth pair of gears for
a 2:3 reduction between the reduction shaft and the camshaft. This will give an overall
gear reduction of 1:3 between the crankshaft and the camshaft.
The proposed design consideration of an idler shaft as previously described would cause
the camshaft to turn in the opposite direction as before the modification. This, however,
would not be a problem because a new cam will be designed and the lobes on the cam
will be designed 2/3 the size of, and at opposite angles of the previous cam. There should
not be any issues with vibration and balance of the engine because the camshaft is quite
symmetrical about its axis of rotation because the only asymmetrical protrusions are the
lobes. The cam design will be done in Autodesk Inventor and the 3D model will be used
to verify the lift and duration of the valves throughout the entire six strokes.
Instead of paying a lot of money to have this camshaft made, a home-made camshaft
design will be considered. This will be done because it will save money and allow several
attempts at achieving the correct timing. A steel shaft will be used as the base and
machined down so that it fits in the existing bearings in the crankcase. The lobes will be
designed in Inventor and laser cut from steel slightly oversize and then ground down for
more accuracy. Mr. Tubergen has generously offered later cutting services for this
project. The lobes will then be welded onto the shaft at the proper angle. The gear will be
placed on the shaft and will use a key to lock it into position and a pair of setscrews to
keep it there. This will allow for easy removal in case another camshaft needs to be
fabricated.
14
The lower end of the engine will need to be heavily modified for the new camshaft design
to be implemented. This will include building a new cover for the lower end that extends
out and allows room for the idler shaft. This is shown in Figure 5.
Crankshaft
Added Crankcase Cover
Original
Crankcase
Idler Shaft
Idler Shaft Bearing Support
Figure 5: Cutaway view of crankcase modification.
Because the cover needs to extend out, a new bearing will be placed in it for the
crankshaft. This is because the diameter of the crankshaft is reduced inside the new
cover. Also, to have enough of the crankshaft left to attach to driven mechanisms, a
coupling will be used and the crankshaft will be extended. The idler shaft will be
supported by two bearings mounted in the new cover. These bearing will be slotted and
room will be left in the design to shim them for greater accuracy. For ease of fabrication,
the cover will be made from steel plate, welded together as accurately as possible and
then machined for accuracy. The machining will start on the bottom of the cover that the
idler shaft will be mounted on and all bearing holes and mounting holes will be machined
from that reference point. The stock gasket will be used to prevent oil leakage or a new
gasket can be cut from gasket material if the stock gasket wears out.
8.2
Design B: Electronic Control System
The second option, Design B, is to completely remove the cam and actuate the valves
electrically. This will most likely include the use of solenoids and springs as the actuators
to open and close the valves. A whole new head will be designed for this purpose instead
of modifying the current head. This method is already implanted in most modern
automotive engines. The proposed design and equipment will heavily draw from these
previous solutions.
15
This design has many options. First, the decision must be made on whether to use two
solenoids for each valve or only one. Based on the spring rate of the current valve springs
an approximate estimate of the force needed to open the valves is known. Another design
consideration is whether to use springs to assist the solenoids. This would take some of
the load off the solenoid, but still allow the system to be completely controlled
electrically. Because the system will need to be adjusted to allow for slight delay times,
the valves will need to be designed so they do not interfere with the piston even if the
valve timing is off. This will allow modifications to the timing until the engine runs the
most efficiently without breaking valves and causing damage to the engine.
The valves will be actuated using the same ECU as the water injection system. The same
board will be programmed to actuate the solenoids as well as the injector. The proposed
expanded control system is diagramed in Figure 6.
Figure 6: The expanded engine control unit.
A four-stroke cycle program will be written based on the current four-stroke cycle, and
the lift and duration of the valves will mimic that cycle as closely as possible. For the sixstroke cycle, the program will be changed to two thirds the speed and a water injection
cycle will be added.
16
8.3
A huge benefit to having electromechanical valves is the ability to change the engine
from a four stroke to a six stroke with no mechanical changes. All that will need to be
done is to switch programs. Hopefully this can be done on the fly so the engine can be
started up and warmed up in four-stroke mode and then changed over to six-stroke mode
after it is up to temperature.
Building a new head also provides a lot of flexibility in the design. It allows the design to
include a spot for the water injector rather than try to fit it into the current head with
major modifications. Also, with more completely redesigned parts and less modifications,
there is less of a chance of ruining the engine. Another benefit to this design is that it is a
good project in itself. If the six-stroke cycle does not materialize as calculated, the
building of an engine head with an electromechanical drive train that runs on the original
four-stroke cycle will be a great success.
Budget Analysis
The budget shown in Table 1 outlines the estimated costs associated with each design
alternative.
Table 1. Estimated budgets for design alternatives.
Item
Camshaft
Idler Gear
Electric Valves
Crankshaft Position Sensor
Engine
Water injection
Diesel Fuel Injector
Fuel Pump
Pressure Regulator
Control system
Instrumentation
Thermocouples
Pressure sensor
Testing
Dynomometer
Orsat
Total
ENGR 339 Total
8.4
Decision Matrix
Design A Costs
$200
$100
Design B Costs Notes
$0
$200
$300
$0
Provided by Engr. Dept.
$50
$75
$25
$100
$50
$75
$25
$100
Paid for by ENGR 315
$50
$25
$50
$25
$0
$0
$625
$475
$825
$675
Paid for by ENGR 315
17
Various design norms, objectives, and concerns have been combined into a decision
matrix between Design A and B to aid in deciding a design path. Table 1 outlines this
decision matrix. The cost is a proportionality based on the proposed budget in Table 1.
Design B is perceived to be safer than Design A because it has fewer moving parts and is
more easily controlled. Design A is perceived to be more difficult to construct because it
involves moving parts with high stresses and very small tolerances. Design A posses no
adjustability in the physical parts because of the high cost associated with custom
camshafts; whereas Design B can easily be modified by changing the ECU programming.
Design A has higher transparency because of its physical nature. It is generally easier to
conceive how a physical object works than lines of code. Design B is more sustainable
because the parts can be re-used in later research or projects; Design A involves custom
materials that will only work for this one engine under specific circumstances.
Table 2. Decision matrix for the design alternatives.
Criteria
Cost
Safety
Ease of Construction
Adjustability
Transparency
Sustainability
Total
Weight
20
40
10
20
5
5
100
Design A
0.59
0.3
0.4
0
0.6
0.4
33
Design B
0.41
0.7
0.6
1
0.4
0.6
67
Via the decision matrix, the proposed design for the engine modifications is Design B,
the electrical control system. This design offers the best chance of success as well as
fulfilling the design norms.
9.
9.1
Project Management
Heavy consideration has been given to each team member’s personal strengths and
weaknesses. The tasks are divided based on the strengths and skills set of each member.
Task Delegations
9.1.1. Controls
There are two main aspects of controls that need to be addressed. Water control will be
handled mostly by Tim and Andrew as part of their controls class final project. Marc
Eberlein will also help them with the overall engine control system due to his expansive
knowledge of engines.
9.1.2. Thermodynamics
The thermodynamics calculations will be completed by John Mantel and Jim
VanLeeuwen because of their general interest in that particular topic.
9.1.3. Cam Analysis
Along with the modifications to the engine comes an analysis of the camshaft. The
camshaft needs to be addressed either by construction of a new camshaft and gear system
or by an electronic control system. Marc, Jim, and Tim are in charge of this project.
9.1.4. Testing
18
Various emissions, temperature, and power tests need to be carried out on the engine to
collect data before and after modifications have been made. This is a total team effort
simply because of the scope of the task.
9.1.5. Inventor modeling
Detailed model of the engine, cam shaft, cylinder, etc. is to be completed by Andrew and
Marc because of their proficiency in Autodesk Inventor.
9.1.6. Website
Website design and construction will be completed by Tim and Andrew because of their
general interest in that particular topic.
A full Gantt chart with task specifications can be found in Appendix B.
10.
Progress
10.1
Camshaft Reverse Engineering
The timing of the current cam shaft must be known to program the electronic control
system. This was accomplished by attaching a wheel marked with 360 degrees to the
crankshaft. A fixed needle was then placed pointing at the wheel and the crankshaft was
rotated through its two full revolutions while measuring the angle of rotation from top
dead center, and also measuring the movement of the intake and exhaust valves with the
end of a calipers.
Figure 7:Cam timing from top dead center
10.2
Water Injection Control System
The water injection control system as mentioned before was successfully built and test as
part of Engineering 315 Control Systems. The full report on this project can be seen in
Appendix C in the IEEE format it was required in.
19
11.
Conclusion
Through the decision matrix and feasibility report it was decided that, Design B, the
electrically controlled system is the superior method of modifying the engine. This is
because it offers the best chance of success as defined by the decision matrix. The course
of actions resulting from this decision would include buying solenoid valves, conducting
further research, and assembling the electrical control unit. This semester long feasibility
study determined Design A as unfeasible and concluded that Design B will be
implemented in Engineering 340 to achieve the design goals.
12.
Special Thanks
12.1
Ren Tubergen
Mr. Tubergen is owner of Gumbo Product Development and has agreed to work with the
team as an industrial consultant. He has been especially valuable in pointing out risks and
opportunities in our project as well as in providing team and project management advice.
Ned Nielsen
Professor Nielsen is the faculty advisor to Team 14. With experience in automotive
engineering, he is a valuable resource for advice on project issues and has helped us find
contacts for specific help.
Nick Hendriksma
Mr. Hendriksma is an engineer working for the General Motors in the company formerly
known as Delphi. He is extremely knowledgeable on fuel injectors and has agreed to act
as a mentor for our team.
Paulo Ribeiro
Professor Ribeiro has helped the team through his knowledge of control systems. He is
working with several team members on the engine control unit as part of a project for his
Engineering 315 controls class.
David Benson
Professor Benson has provided some guidance for the team for future exhaust gas
composition testing. He is also a valuable contact in the Calvin College Chemistry
Department who has volunteered some of his time and knowledge to help the team.
Gary Geukes
Mr. Geukes is founder of FastBikes – USA who generously allowed the team to attempt
dynamometer tests on his motorcycle dynamometer. Despite the unsuccessful result of
those tests, his help is much appreciated.
12.2
12.3
12.4
12.5
12.6
20
13.
Appendix A – Thermodynamic Calculations
"Analysis of thermodynamic states after each of the six engine cycles."
"Specs"
diameter_bore=90[mm]
Stroke_bore=66[mm]
r=8
r=V_open/V_comp
V_open-V_comp=pi*(diameter_bore/2)^2*Stroke_bore
"Thermodynamic state 1: Intake"
T_outside=25[C]
P_inside=P_atm
V_air=V_open
T_cylinder_2=100[C]
P_atm=101.3[kPa]
m_dot_fuel=(2/3)[gal/hour]
m_dot_N2=1
m_dot_O2=1
h_O2=enthalpy(O2,t=T_outside)
h_N2=enthalpy(N2,t=T_outside)
h_fuel=enthalpy(C8H18,t=T_outside)
m_dot_air=0.79*m_dot_N2+0.21*m__dotO2
E_dot_air=m_dot_O2*h_O2+m_dot_N2*h_N2
E_dot_fuel=m_dot_fuel*h_fuel
E_dot_intake=E_dot_air+E_dot_fuel
"PRESSURE WASHER FROM HOME"
"Thermodynamic state 2: Compression"
P_2=P_inside*8
s_2=entropy(air, t=T_cylinder_2, p=P_2)
T_cylinder_2=T_cylinder_1
V_air_2=V_air_1
m_fuel_2=m_fuel_1
h_air_2=enthalpy(air, t=T_cylinder_2)
h_fuel_2=.87*enthalpy(n-OCTANE, p=P_2, t=T_cylinder_2)+.13*enthalpy(n-HEPTANE, p=P_2,
t=T_cylinder_2)
E_dot_air_2=m_dot_air_2*h_air_2
E_dot_fuel_2=m_dot_fuel_2*h_fuel_2
21
E_dot_compression=E_dot_air+E_dot_gas
"Thermodynamic state 3: Combustion"
m_exhaust=1
V_exhaust=1
T_cylinder_3=1
Power_shaft_1=1
s_3=s_2
AF_actual=35
"Estimation based on IC lab from last year."
"Combustion Equation"
"C8H18(liquid) + (n_O2)*O2 + (3.76*n_O2)*N2 = (a)*C8H18(vapor) + (b)*CO2 + (c)*H2O + (d)*O2 +
(e)*N2"
"Combustion Equation"
2*n_O2=2*b+c+2*d
8=8*a+b
18=18*a+2*c
2*3.76*n_O2=2*e
composition."
n_O2=(1-a)*12.5
n_O2*4.76=AF_actual
"Value of 3.76 given by assumption of air
"Thermodynamic state 4: Recompression"
P_4=8*P_3
T_cylinder_4=1
m_exhaust_4=1
V_exhaust_4=1
"Thermodynamic state 5: Re-expansion"
m_water=1
T_cylinder_5=1
Power_shaft_2=1
V_steam=1
T_water=20[C]
C_p_water=1
E_dot_steam=m_dot_water*C_p_water*(T_cylinder-T_water)
E_reexpansion=E_dot_steam+Power_shaft_2
22
"Thermodynamic state 6: Exhaust"
T_steam=275[C]
m_dot_exhaust=m_dot_fuel+m_dot_air
P_atm_6=P_atm
h_fuel_6=enthalpy(C8H18,t=T_steam)
h_CO2_6=enthalpy(CO2,t=T_steam)
h_H2O_6=enthalpy(H2O,t=T_steam)
h_O2_6=enthalpy(O2,t=T_steam)
h_N2_6=enthalpy(N2,t=T_steam)
E_dot_fuel=m_dot_exhaust*((y_fuel*h_fuel_6)/MW_fuel)
E_dot_CO2=m_dot_CO2*((y_CO2*h_CO2_6)/MW_CO2)
E_dot_H2O=m_dot_H2O*((y_H2O*h_H2O_6)/MW_H2O)
E_dot_O2=m_dot_O2*((y_O2*h_O2_6)/MW_O2)
E_dot_N2=m_dot_N2*((y_N2*h_N2_6)/MW_N2)
E_dot_exhaust=E_dot_fuel+E_dot_CO2+E_dot_H2O+E_dot_O2+E_dot_N
23
14.
Appendix B – Gantt Chart
24
15.
1
References
United States Patent and Trademark Office. <http://patft.uspto.gov>
Ibid.
3
Ibid.
4
Ibid.
5
Ibid.
6
“Inside Bruce Crower’s Six-Stroke Engine.” Autoweek.com.
<http://www.autoweek.com/article/20060227/FREE/302270007>
7
Cumming, Alexander C. and Sydney Alexander Kay. A Text-book of Quantitative Chemical
Analysis. (New York: John Wiley and Sons, 1913), 269-272.
8
"Gas Chromatography." Wake Forest University Chemistry Department, n.d. Web. 22 Nov.
2009. <http://www.wfu.edu/chem/courses/organic/GC/index.html>.
9
Colorado University Organic Chemistry Lab Manual, n.d. Web. 22 Nov. 2009.
<http://orgchem.colorado.edu/hndbksupport/GC/GC.html>.
10
Tissue, Brian M. "Gas Chromatography." Virginia Tech University Chemistry Department,
n.d. Web. 22 Nov. 2009. <http://www.files.chem.vt.edu/chem-ed/sep/gc/gc.html>.
2