Session T3F
A WEB-BASED MULTI-MEDIA VIRTUAL EXPERIMENT
Sushil Chaturvedi1 , Osman Akan2 , Sebastian Bawab3 , Tarek Abdel-Salam4 , and
Manjunath Venkataramana5
Abstract – A physical experiment from the undergraduate
thermo-fluids laboratory titled “Venturimeter as a Flow
Measuring Device” has been chosen for its mapping into the
virtual domain, as a computer-based experiment. The virtual
experiment described in the present study, combines three
unique aspects simultaneously: use of computer generated
(virtual) data to recreate the physical phenomenon, virtual
experimentation and measurement on a computer screen,
and coupling of the virtual experiment with the LabVIEW
software to introduce students to digital data acquisition and
analysis. The proposed multi-media module has three submodules namely, the physical sub-module, the experimental
details sub-module, and the virtual experiment sub-module,
for introducing students to physical system configuration,
experimental procedure, and detailed instructions for
conducting virtual experimentation, data acquisition and
analysis. The proposed module is expected to impact the
development of virtual engineering laboratories for webbased distance learning undergraduate engineering
programs
Index Terms – Virtual experiment, web-based laboratories,
interactive experimentation, e-devices.
INTRODUCTION
There is a scarcity of undergraduate engineering programs
available through distance learning networks. Resistance to
the implementation of web-based engineering programs
stems from the fact that engineering is perceived, and rightly
so, as a hands-on discipline. As a result, there remains
considerable skepticism among engineering faculty, and
even among students, about offering of undergraduate
engineering programs on distance learning networks. There
are two notable exceptions, however. In 1998, the University
of North Dakota began offering distance learning
undergraduate engineering programs for industry, using
courses delivered to off-campus locations through the
asynchronous video-transmission of lectures [1]. The
laboratory courses are conducted on-campus in two-week
sessions during the summer. Another example is the College
of Engineering and Technology at Old Dominion University,
which
offers
mechanical,
civil,
and
electrical
engineeringtechnology programs via Old Dominion
University’s TELETECHNET distance learning network.
Live televised courses are beamed to several receiving sites
in Virginia and across the country. Laboratory courses are
offered through creation of videotapes and CD-ROMS of all
experiments for viewing by distance students [2-3].
However, the videotape or CD-ROM based delivery
methods fail to incorporate two critical aspects of laboratory
experiments. First, the distance students are a passive
audience, not actively participating or exercising control
generally afforded by a real-life experimental set-up.
Second, there is also absence of teamwork and
communication among students – critical ingredients of an
engineering education – in the video or CD-ROM based
laboratory instruction. The Old Dominion University
engineering technology programs have also used in past a
mobile thermo -fluids laboratory for providing access to
distance students at remote locations. However, this
approach has been abandoned in favor of the CD-ROM and
video-based laboratory instruction due to difficulty of
serving many centers with one mobile laboratory.
STATEMENT O F THE PROBLEM
The virtual absence of undergraduate engineering programs
on distance learning networks can be attributed primarily to
a lack of high quality web-based virtual laboratories capable
of capturing the details of lab experiments, including handson activities and the collaborative work environment that is
normally found in physical laboratories. This has proven to
be a great impediment to offering of undergraduate
engineering degree programs to distance learners. However,
with recent developments in computer, communication and
internet technologies, it has become possible to address
problems inherent in development of web-based virtual
engineering laboratories. Using recent paradigm shifts in
visualization technology, together with advances in
computer solution of physical phenomena and orders of
magnitude increases in computer power, design and
implementation of truly interactive, life -like virtual
experiments has become feasible. The present work
demonstrates this by mapping a physical experiment in the
undergraduate thermo -fluids laboratory into a web-based
virtual experiment.
1
Sushil Chaturvedi, Chairman and Professor, Old Dominion University, Mechanical Engineering Department, Norfolk, VA 23529 schaturv@odu.edu
Osman Akan, Chairman and Professor, Old Dominion University, Civil and Environmental Engineering Department, Norfolk, VA 23529 oakan@odu.edu
3
Sebastian Bawab, Associate Professor, Old Dominion University, Mechanical Engineering Department, Norfolk, VA 23529 sbawab@lions.odu.edu
4
Tarek Abdel-Salam, Old Dominion University, Mechanical Engineering Department, Norfolk, VA 23529 tabdelsa@odu.edu
5
Manjunath Venkataramana, Graduate Assistant, Old Dominion University, Mechanical Engineering Department, Norfolk, VA 23529 mvenk001@odu.edu
2
0-7803-7961-6/03/$17.00 © 2003 IEEE
November 5-8, 2003, Boulder, CO
33 rd ASEE/IEEE Frontiers in Education Conference
T3F-3
Session T3F
This project will bridge a critical gap that in authors’
opinion will make offering of web-based undergraduate
programs more commonplace in the near future. A second,
but an equally important, benefit will be that an instructor
will be able to bring virtual experiments to lecture classes in
conventional on-campus courses for clarification of concepts
and reinforcement of physical principles. Instead of taking
students to a laboratory demonstration during a lecture, an
instructor will be able to use computer-based virtual
experiment modules in classroom to illuminate and reinforce
basic concepts. We can even say that this virtual tool will
make it possible for an instructor to bring the (virtual)
laboratory to lecture classes, something that is generally not
possible in the physical doma in. Last but not least, virtual
experiments will facilitate development of hybrid
laboratories in future that would employ an optimal mix of
physical and virtual experiments to provide students handson experience both in physical as well as virtual domains.
The present study incorporates two factors that are
expected to facilitate development of high quality web-based
laboratories that would mimic physical laboratories quite
closely. These factors are:
(i) Recreation of Physical Phenomena in the Virtual
Domain – there is a need to map the underlying
phenomena in physical experiments into the virtual
domain by using the computational fluid dynamics
(CFD) codes. The computed data is created and stored
in virtual data modules a priori. These virtual data
modules are activated by an experimenter, through an
animation program, to recreate the physical phenomena
on the computer screen.
(ii) Hands-on Activities – Currently available laboratory
courses for distance learners do not provide them the
same environment and experience as an on-campus
student encounters in campus-based physical
laboratories. For instance, distance students are
generally not able to manipulate valves (in a fluids
experiment), change flow parameters, and make
measurements on a computer screen as students can do
in a physical setting. The authors have developed an
interactive virtual experimentation methodology that
would enable distance learner to perform a virtual
experiment interactively on a computer screen. The
website www.mem.odu.edu/simulations, developed by
authors, gives a demonstration of this methodology.
M ETHODOLOGY
The Proposed Thermo-Fluids Virtual Experiment
physical configuration of the experiment is shown in Fig. 1.
The undergraduate thermo -fluids laboratory course (ME
305) has been chosen for transformation to a web-based
virtual laboratory (Fig. 2). The laboratory has seven
experiments, and it is expected that the virtual laboratory
will be operational within two years. In addition to receiving
an introduction to thermodynamics and fluid mechanics
experimentation techniques, students in this course are also
exposed to digital data acquisition using software, such as
LabVIEW, and statistical treatment of data and errors.
FIGURE 1
PHYSICAL CONFIGURATION FOR THE VENTURIMETER EXPERIMENT
The virtual experiment module is uploaded on the
college computer server at the web address
www.mem.odu.edu/simulations. The infrastructure set-up is
shown in Fig. 3. The server through the internet can support
several users simultaneously. It is to be noted that in its
current configuration, the module permits distance learners
to perform the experiment interactively on the computer
screen but not collaboratively. Aspects dealing with virtual
collaboration among geographically distributed users will be
discussed in a subsequent paper.
Computational Environment and
Virtual Data Modules
The underlying physical phenomenon in the venturimeter
experiment is visualized in the virtual domain by using the
Computational Fluid Dynamics (CFD) code “Fluent” [4].
Due to advances in computer hardware and software, the
methodology of numerical prediction of a physical
phenomenon on computers has become very reliable and, in
many cases, an alternative to experiments. The Fluent code
uses a finite volume numerical scheme to discretize the
physical laws governing the phenomenon on a numerical
grid [5]. It should be noted that due to non-linearity of
governing equations, the CFD code generally requires
The present study has developed a virtual experiment
module that allows a distance learner to access it through the
internet, and conduct the experiment much in the way an oncampus student performs it in a real laboratory. We chose
the experiment titled “Venturimeter as a Flow Measuring
Device” for transformation to the virtual domain. The
0-7803-7961-6/03/$17.00 © 2003 IEEE
November 5-8, 2003, Boulder, CO
33 rd ASEE/IEEE Frontiers in Education Conference
T3F-4
Session T3F
FIGURE 2
WEB-BASED VIRTUAL THERMO - FLUIDS LABORATORY
considerable CPU time, ranging from a few minutes to a few
hours, depending on the grid refinement and the capabilities
of the personal computers. As a result, all possible cases that
an experimenter is going to execute during this virtual
experiment are pre-calculated and stored in virtual data files.
For instance, in the present case, results are calculated and
stored for seven free stream velocities for subsequent
visualization during the execution of the virtual experiment.
STRUCTURE OF THE VIRTUAL EXPERIMENT
M ODULE
The structure of the virtual module shown in Fig. 4. The
physical sub-module, using audio and video capabilities,
acquaints students with the physical layout of the actual
experiment. It also contains a four minute long video movie,
describing the experimental procedure. The experimental
procedure sub-module contains in the text form information
about objectives, procedures, equations and analysis. The
virtual experiment sub-module contains all virtual data
modules needed to perform the experiment, as well as a stepby-step procedure for conducting the virtual experiment,
which is shown on the left side of the window in Fig. 5.
DETAILS OF VIRTUAL EXPERIMENT PROCEDURE
FIGURE 3
I NFRASTRUCTURE SET- UP FOR VIRTUAL EXPERIMENT
It should be noted that in its current configuration the
proposed module replicates only the core features of the
experiment. The physical experiment involves measurement
of two quantities, namely the flowrate and the pressure drop
from the maximum to the minimum cross-section of the
venturimeter. In the physical experiment, the flowrate is
determined by measuring time taken to collect a given
volume of water in a tank attached to the hydraulic bench
0-7803-7961-6/03/$17.00 © 2003 IEEE
November 5-8, 2003, Boulder, CO
33 rd ASEE/IEEE Frontiers in Education Conference
T3F-5
Session T3F
FIGURE 4
STRUCTURE OF THE WEB- BASED VIRTUAL EXPERIMENT MODULE
FIGURE 5
VIRTUAL EXPERIMENT SUB- MODULE
0-7803-7961-6/03/$17.00 © 2003 IEEE
November 5-8, 2003, Boulder, CO
33 rd ASEE/IEEE Frontiers in Education Conference
T3F-6
Session T3F
(Fig. 1). The pressure drop is measured in terms of water
height difference in the piezometer tubes attached to the
maximum and minimum cross-sections of the venturimeter.
The height difference is gaged by a differential pressure
transducer whose readings are transferred to the LabVIEW R
software through an analog to digital (A/D) card. The
pressure differential reading appears on the computer screen
as water level heights in piezometric tubes. Students use the
LabVIEW R software to write a program to convert the
pressure drop and flowrate into the coefficient of
venturimeter (cv), and plot it as a function of Reynolds
number (Re) for a number of volumetric flowrates.
Although the virtual experiment captures most of the
details of the physical experiment, one difference should be
noted. Unlike the physical experiment which is closed loop,
and involves volume flowrate measurement through
measurement of volume and time, the virtual experiment is
depicted as an open loop system, and the flowrate is read
from an e-flowmeter located on the inlet part of the virtual
experiment set-up (Fig. 5). The flowrate is manipulated by
an e-valve with seven flowrate settings, and the e-flowmeter,
e-valve and e-venturi are all programmed to act in a
consistent manner. For instance, clicking the mouse on the evalve at setting 1 would open the valve, and the indicator on
the dial of the e-flowmeter will move to a preset value. Also,
the water level in piezometric tubes will adjust to levels
predicted by the CFD program for that valve setting and
flowrate (Fig. 6). We avoided replicating the collection tank
process because it would have involved significant
additional animation complexities without adding much to
the enhancement of the quality of the virtual experiment.
The experiment is commenced by clicking the valve to the
selected open position, and clicking the pump on. This
creates a rush of rising water, and eventual stabilization of
water level in the piezometer tubes (Fig. 6). Since in the real
experiment, the tube water level generally fluctuates around
a mean value, a fluctuating motion of the water meniscus
around the mean height was also incorporated to achieve
more realistic animation. The pressure reading in the
piezometer tubes connected to the inlet and the throat
sections of the venturimeter are recorded for the selected
flowrate. The coefficient of the venturimeter (cv ) is related to
measured flowrate, and pressure drop by the following
equation.
Q& Actual = cv A2
where
2(P − P21 )
ρ
A 
1 −  2 
 A1 
2
(1)
QActual is the measured flowrate, A1 and A2 are inlet
FIGURE 6
P IEZOMETER TUBE READINGS FOR HIGHER FLOWRATE CASE
Using flowrate and pressure drop data, and the Eq. (1),
students can determine the values of cv and Reynolds
number, Re, for a graphical representation on a cv-Re
diagram. After completing one set of experiment, a higher
flowrate case can be implemented by following the virtual
experiment procedure. It should be noted here that to enable
the virtual module to yield data, two approaches can be used.
First, experimental data from the physical experiment can be
used in the animation program as the virtual data for the
computer simulated experiment. Alternatively, computational fluid dynamics techniques can be used to predict
pressure drop and venturimeter coefficient for the chosen
venturimeter geometry for a number of flowrates (Reynolds
number). The data from the virtual experiment is coupled to
the LabVIEW R software through a link that students can
actuate to record and process the data. Students can also,
using programming facilitated by LabVIEW R, can calculate
and plot cv versus Re (Fig. 7). In this regard, the virtual
experiment, preserves an important feature of the physical
experiment that allows students to acquire and process data
using LabVIEW R.
CONCLUSIONS
A physical laboratory experiment in the undergraduate
thermo -fluids laboratory has been transformed into a webbased virtual experiment. The web-based module can be
accessed by distance learners through the internet to perform
experiments interactively on a computer screen. The virtual
experiment has also been coupled to the LabVIEW R to
enable students to record data digitally, and to perform data
analysis, using programming features in the LabVIEW R
software. Based on instructor’s observation, the res ults from
this project have been very encouraging, and the virtual
experiment has been well received by students in the
and throat areas respectively, ρ is water density, and (P1 –
P2 ) is the pressure drop from the inlet to throat section.
0-7803-7961-6/03/$17.00 © 2003 IEEE
November 5-8, 2003, Boulder, CO
33 rd ASEE/IEEE Frontiers in Education Conference
T3F-7
Session T3F
thermo -fluid laboratory course. The on-campus students
have used the module as a primer before they perform the
physical experiment, and they have used the LabVIEW R
linkage to do data analysis. The results, so far, have met our
expectation, and we are continuing efforts to transform
additional physical experiments into web-based virtual
experiments.
REFERENCES
[1]
Benjamin, N. N., et al., “The Development of an Undergraduate
Distance Learning Degree for Industry – A University/Industry
Collaboration,” Journal of Engineering Education, Vol. 87, No. 3, pp.
277-282.
[2]
Crossman, G. R., “A CD-ROM Based Laboratory Course in Fluid
Mechanics,” Proceedings of the 2001 American Society of
Engineering Education Annual Conference and Exposition Session
2247.
[3]
Considine, C. L. and Lewis, Jr., V. W., “Assessment Methods for
Virtual Technology,” Proceedings of the 2001 American Society of
Engineering Education Annual Conference and Exposition Session
2247.
[4]
“Fluent,” Fluent Corporation, New Hampshire, 2002.
[5] Patankar, S. V., “Numerical Heat Transfer and Fluid Flow,” McGrawHill, Inc., New York, 1980.
FIGURE 7
V ARIATION OF C V WITH REYNOLDS NUMBER
0-7803-7961-6/03/$17.00 © 2003 IEEE
November 5-8, 2003, Boulder, CO
33 rd ASEE/IEEE Frontiers in Education Conference
T3F-8