As consultants who specialize in simulation, we continue to expand our physical testing capabilities. For example, the image below depicts the results from both testing and CFD on a Raspberry Pi unit, which are very compact Linux machines we use for data acquisition and other tasks.
Physical testing of a Raspberry Pi board using an IR camera (left) closely matches the results of a CFD simulation (right).
There are several reasons why we are investing in physical testing equipment. First, we use test results as a means of continually benchmarking our simulation software and techniques. Physical testing is essentially a simulation feedback loop; we take the findings and apply them to future studies to get better results more quickly.
Physical testing is also used to confirm actual design performance. FEA and CFD simulations can significantly reduce the need for testing and wasted prototypes; however they do not necessarily eliminate a final physical test. Some inputs required for simulation, such as emissivities or thermal resistances can be difficult to obtain; a physical test provides the final validation of what the trends in simulation have revealed. Recently, we were contracted to perform a CFD simulation of an older industrial building. Certain parameters, such as ventilation fan flow rates were unknown at the time. As a result, physical testing was first required to obtain these critical inputs before the simulation runs could be initiated.
Some performance parameters, such as these natural convection currents, can be challenging to measure and visualize with physical testing.
Finally, although we remain passionate about virtual simulation, we still like to "get our hands dirty". When we are not busy running CFD or FEA simulations, we are usually out in the garage wrenching on trucks or dirt bikes. Physical testing challenges our design fabrication skills, whether its building wind tunnels and flow benches or using our programming and soldering skills when developing custom data aquisition systems.