This is from the NASA website. It talks about swimsuit design for the US olympic team. The previous post talks about the similarities of water and air flow, so I posted it to show "Studious" types are aware of the similarities!

One area Wilkinson focuses on is drag reduction … how to make something propel though air or water faster and more efficiently. That was Wilkinson's task for Speedo … to test swimsuit material for drag.

"We evaluated the surface roughness effects of nearly 60 fabrics or patterns in one of our small low speed wind tunnels," said Wilkinson. "We were assessing which fabrics and weaves had the lowest drag. The tests have generally shown the smoother the fabric, the lower the drag."

But how can you test a material that's supposed to be used in water in a wind tunnel that uses air? It turns out that air and water obey the same physical laws of motion, so a wind tunnel can simulate similar drag a fabric would experience in water. Testing in air is also less expensive, simpler and offers more testing options than testing in water.