There isn't a standard set of "three tests" in wind tunnels, but here are three common types of tests conducted in a wind tunnel:
1. Aerodynamic Force and Moment Measurement: This involves measuring the forces (lift, drag, side force) and moments (pitching, rolling, yawing) acting on a model placed in the airflow. This helps engineers understand how the air interacts with the object and design it for optimal performance.
2. Flow Visualization: This uses techniques like smoke or tufts to visualize the airflow patterns around the model. This can help identify areas of separation, turbulence, or other flow phenomena that could impact the object's performance.
3. Pressure Measurement: This involves measuring the pressure distribution on the model's surface. This information can help engineers understand the forces acting on the object, identify areas of high pressure (which can lead to drag) and areas of low pressure (which can lead to lift).
In addition to these basic tests, wind tunnels can be used for a variety of other purposes, such as testing the effects of rain, ice, or snow on an object's performance.
Let me know if you had something different in mind!