Wind TunnelsIn this report, I will talk about the wind tunnel. I will describe what they are used for. The different types of wind tunnels, from slow speed subsonic tunnels to high speed hypersonic tunnels. I will also give some examples of wind tunnels used today. The wind tunnel is a device used by many people, from high school students to NASA engineers. The wind tunnel is a device used to test aircraft to see how they perform under certain conditions. The plane can be as big as a full-size 747 or as small as a matchstick. To understand how a wind tunnel is used to assist in the design process, you need to know how a wind tunnel works. How Wind Tunnels Work A wind tunnel is a machine used to fly aircraft, missiles, engines and rockets to the ground under prerequisites. set conditions. With a blower, you can choose air speed, pressure, altitude, and temperature, to name a few things. A wind tunnel usually has the appearance of a tube with which the wind is produced by a large fan to circulate on what they are testing (airplane, missiles, rockets, etc.) or on a model thereof. The object in the wind tunnel is fixed and placed in the test section of the tunnel and instruments are placed on the model to record the aerodynamic forces acting on the model. Types of Wind Tunnels There are four basic types of wind tunnels. Which are weakly subsonic, transonic, supersonic and hypersonic. Wind tunnels are classified according to the speed they can produce. Subsonic has a speed less than the speed of sound. The transonic has a speed approximately equal to the speed of sound (Mach 1,760 miles per hour at sea level). . The supersonic (Mach 2.75 to 4.96) has a speed of about five times the speed of sound and the fastest of these is the hypersonic (Mach 39.5) which has a speed of over 30 000 miles per hour. Wind tunnel testing There are basically two types of wind tunnel testing which are static stability and pressure testing. With these two tests you can determine the aerodynamic characteristics of the aircraft. The static stability test measures the moments of force due to the external characteristic. These forces include axial, lateral and normal forces, rolling, pitching and yaw moments. These forces are determined using a strain gauge located on the external part of the plane. It measures external flow fields. Then the shadowgraph is used to show the shock waves and flow fields at a certain speed or viewing angle.