CSUN_Engineering_ForSPectra2.jpgDrones, once synonymous with remote military recognizance and strikes, have gained mainstream ground over recent years. Hobbyist drones are now readily available online and at big box stores, and the drones of Google’s Project Wing and Amazon’s Prime Air are being field tested to deliver packages.

Advances in technology have brought a push for better and smaller and more capable drones, explains Vibhav Durgesh, assistant professor of mechanical engineering, but in order to design these improved aircraft, it’s critical to know how they behave when they fly, in myriad conditions. Existing literature uses data for airfoils (wings) generated by government agencies and research labs for large airplanes, which fly much, much faster than drones. Limited comparable data currently exists for airfoils at low Reynolds numbers. (Reynolds number refers to an important dimensionless quantity in fluid mechanics that is used to help predict flow patterns in different fluid flow situations. It is widely used in many applications ranging from liquid flow in a pipe to the passage of air over an aircraft wing.)

“Making measurements at very low speeds is very tricky, and you have to design the experimental capability,” says Durghesh. “Fortunately, here at CSUN, we already have it.”

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In fact, Durgesh has spent two years developing the capability in the college’s Experimental Fluids and Aerodynamics Laboratory to test airfoils at slow speeds. This includes a state-of-the-art water tunnel and sophisticated instruments such as stereoscopic particle image velocimetry (PIV) and hydrogen bubble flow visualization systems to take the measurements.

Durgesh, who has two graduate students working with him on the research, has submitted his first conference paper with his flow visualization results, which can be used to explain certain lift characteristics of an airfoil.

“Unmanned aircraft systems have potential in both military and civilian applications and will continue to grow in coming years,” he says. “It’s one of the driving forces for this research.”