This product is used for conducting theoretical analysis and experimental research on gas flow and nozzle calculations in the disciplines of Engineering Thermodynamics and Aerodynamics; The equipment as a whole consists of a gas source, a testing section, pressure measurement, and a regulating valve group. Through the cooperation of the air pump and the valve, the pressure distribution curve of the converging diverging nozzle (Laval nozzle) can be measured, and the inlet pressure and back pressure of the nozzle can be adjusted.