Control of Wind Tunnel Test Temperature Using a Mathematical Model

An example of mathematical-model based control is presented, in which a mathematical model for the behavior of a low-speed wind tunnel is used to determine the control inputs necessary to control the test-section temperature during rapid changes in test windspeed. Development of the mathematical model from basic fluid-mechanic equations is shown, as well as the experimental measurements that were performed to determine the values of various model parameters that produce a high-fidelity simulation of the behavior of the actual wind tunnel. The results show that the mathematical model, when properly benchmarked against the actual wind-tunnel performance, can be used for accurate feedforward control of the wind-tunnel temperature, even without a complementing PID loop to reduce residual error.