The largest wind tunnel in the world is at the National Full-Scale Aerodynamics Complex at NASA Ames Research Center . Wind tunnels aren't just used to test airplanes. Anything that has air blowing around or past it can be tested in a wind tunnel. Some engineers have put models of spacecraft, cars, trucks, trains, even road signs, buildings, or entire cities in wind tunnels to see how to improve their designs. Here are the different aircraft and spacecraft that have been tested in NASA's Unitary Plan Wind Tunnels .
Computation is when scientists use computers to solve math and science problems.
As supercomputers become faster and more powerful, they are able to save researchers a lot of time by doing complicated airplane design calculations quickly and accurately. Computers can predict things like how air will flow around an airplane or how the structures inside the airplane will support its weight - before the airplane is actually built. The computer first needs to create a mathematical model of the airplane being tested. Next, a computer program is run that calculates specific numerical values at different points on the model. For example, if the program is written to figure out the pressure around an airplane model, it finds the individual pressures at several points on the model to make a good prediction at what the overall pressure looks like.