Research On Model Construction And Control Of Mach Number For Wind Tunnel

With the development of aerial and air space technology, the design and research of allkinds of aircrafts more and more depends on the Wind-tunnel test. The quantity of data fromWind-tunnel flow test, especially the transonic-supersonic characteristic, influences theaerodynamic character of the aircraft directly. The main task of control system of Wind-tunnelis how to increase the controlling accuracy, to improve the character of flow field ofWind-tunnel, and to obtain more precise data. It is also the base of designing aircraft. Thethesis has studied the design of controller of the parameter of XX sonic wind tunnel, and it’sadaptive control system.XX sonic wind tunnel is injector driven transonic wind tunnel, so it demands shortsetting—up time for steady flowing field, supernal control precision and well distributedairflow. The Mach number in test section and the total pressure are difficult to control becauseof the unpredictable changes in wind tunnel process dynamics and restriction for air storagevolume. To cope with the problem, a modeling and simulation method is presented. Themethod is proved to be effective in practice.The main works include:（1）According to the characteristic of wind tunnel, an identification experiment forMach number in test section and the total pressure is designed；（2）With the help of the leads of CAAA (China Academry of Aerospace Aerodynamics),the experiment is used in the wind tunnel, and plenty of experimental data is abstained. ASISO model is established based on the experiment data, using least—square method；（3）APID controller is designed using SPAM (specified phase and amplitude margins)method. The controller is used in adjusting phase to guarantee ideal steady precision. To copewith the problem that there is strong coupling between Mach number, a decoupling controlleris proposed using feedforward method；（4） An open—closed associating method is proposed using optimum control and tandemPID control. This method is effective in the staring—up phase in the wind tunnel.