While teaching at an Aviation High School, Jack Gilbert found that the study of aerodynamic principles fascinated his students. Many of his students could grasp math and science concepts if there was a real world connection to the formulas. Surprisingly, many aerodynamic formulas only require simple algebra. But how many schools can afford a wind tunnel? None needs to now, as Gilbert and his company MechNet have developed an educational initiative where students design and operate their own wind tunnel experiments using remote Internet control of MechNet’s tunnels.
MechNet Inc., of Mentor, Ohio, is starting a new and innovative service to allow schools and universities to operate research grade wind tunnels via the internet to support STEM (Science, Technology, Engineering and Math) education. Using a wind tunnel may not seem like an obvious tool to teach basic math formulas but surprisingly many of the formulas only require simple algebra: for instance, the continuity equation used with a venturi is as simple as V1 x A1 = V2 x A2. This gains the students interest and gives them the confidence to continue with more and more complex math. Some of the more advanced lessons are calculus-based.
The important thing is that now the math becomes a tool to solve a problem. True engineering involves first asking the question, “What do I want to achieve?” - followed quickly by the question, “What do I need to learn before I can answer the first question?” At this point many students may see a true need for learning how to do a particular math formula even though they are not currently achieving at a high level in math class – as a first step to understanding why the math is important.
In order to be successful, an engineer must not only have the knowledge of many separate concepts, but also the ability to integrate these concepts into a practical understanding. Considering and applying these concepts provides students with an understanding of science and engineering so they can make an informed choice about the suitability of a career in that field. This type of instruction also makes engineering fun, making it more likely they would consider a career in science and engineering.
To provide data with the degree of accuracy required to conduct math formulas requires that the wind tunnel and data acquisition system are of research quality. The wind tunnel must produce a laminar, low turbulence air flow and all of the instrumentation must be extremely accurate. Unfortunately the cost and difficulty to operate these systems makes the operation of a wind tunnel on site infeasible for many schools. Operating the wind tunnels remotely solves this issue since the schools will only pay a low hourly fee for the time they are actually operating the wind tunnel. Plus the wind tunnel will be completely configured for the test they have requested. The schools will not be required to change models and reconnect all of the complex instrumentation tubing required.
Multiple FLOTEK wind tunnels by GDJ Inc. (www.gdjinc.com) will be equipped with a wide range of models such as wind turbine blades, different NACA profile airfoils, venturis, golf balls, and so on. An instructor will be able the show the difference in lift data between a NACA 4415, NACA2415 and NACA0015 airfoil by just logging into a different IP address. They actually could operate two wind tunnels at once and show the data difference on two monitors simultaneously.
The wind tunnels will interface to a state-of-the-art system based on National Instruments hardware and LabVIEW, which will control the wind tunnel and display performance data. The application was developed by Viewpoint Systems.
With this system the experience of operating the wind tunnel remotely, will be the same for the students as if they where in the same room as the wind tunnel. Interactivity will include adjustable test section velocity and airfoil angle attack giving the student complete control of the experiment. By adding audio and video the students will be able to actually see the effects of stall on airfoil as the angle of attack is increased. A side benefit of this process is that the ability to remotely control a device located in another distant location may well be more exciting to the student than a device that is immediately in front of them.
Wind tunnels will also be made available for students to send models to Mech-Net for testing. Students will make their own wind turbine blades, 1/10th scale car bodies and other experiments. Once the experiment is mounted they will log in and conduct the experiment in real time on their own model.
Wind Tunnel Design
The tunnel hardware was designed in conjunction with NASA Glenn Research Center in Cleveland, Ohio to provide ultra-low turbulence, straight-line (laminar) air flow, permitting true aerodynamic engineering, data acquisition and analysis. FLOTEK wind tunnels bring advanced aeronautic design principles to the high school and college laboratory. The standard models are the FLOTEK 1440 wind tunnel with 12’ x 12” x 36” test section where air flow velocity can reach up to 185 mph and the Flotek 360, with a 6” x 6” x 18” test section.. The tunnel is fitted with a 20-tube manometer for enhanced visual reference with a two-component balance-beam for measurement of drag and side force. Larger custom wind tunnels will be used for student based model testing. A wind tunnel with a round test section is being developed for wind turbine blade testing.
Data Acquisition and Control System
The National Instruments platform selected for data acquisition and control was the CompactRIO. This platform was perfectly suited since it offered the requisite size, channel count, signal conditioning, and realtime control capabilities. The NI CompactRIO programmable automation controller (PAC) is a low-cost reconfigurable control and acquisition system designed for applications that require high performance and reliability. The system combines an open embedded architecture with small size, extreme ruggedness, and hotswappable industrial I/O modules. CompactRIO is powered by reconfigurable I/O (RIO) fieldprogrammable gate array (FPGA) technology.
See the National Instruments article on
R and D
The software was written in LabVIEW Realtime and LabVIEW FPGA by Viewpoint Systems, of Rochester, New York, a Select Partner of the National Instruments Alliance program (www.viewpointusa.com). We had looked at some other solutions for remote lab control, but they didn’t provide the tight closed loop control needed for other applications we provide, such as engine dynamometers.
The application allows real-time display of up to 16 readings of pressure and velocity over the test model while controlling the angle of attack and fan RPM. An airfoil stepper motor controller allows for computer control of the airfoil angle of attack from a slide bar on the Remote Panel and an additional stepper motor will be used to raise and lower a yarn streamer for visual enhancement. All sensors and control actuators are calibrated for accuracy.
Operating the wind tunnels over the Internet allows access to expensive research grade equipment at a very affordable cost. Schools will not have to maintain the equipment or change models. By combining the powerful feature-set of the CompactRIO and FPGA technology and the NI Remote Panel capability, the system is able to meet the needs of STEMbased education. Educators and students from all over the world can now log-on and deliver classroom instruction with real-time data and presentation of a model wind tunnel operating without the hassle of owning and maintaining one. This system also provides an excellent opportunity for a business to provide an outreach program for their local school. A business can provide cutting edge technology to their local school with little or no actual time investment on their part.