The measurement and control of the model attitude angle in airfoil wind tunnel test

This paper describes the characteristics of model attitude angle measurement and control system for normal and dynamic test,and the effective methods for advancing the precision and accuracy of angle measurement in NF-3 low speed airfoil wind tunnel.Used a DC servo system based-micro computer,we have achieved the precision of the model attitude angle in±3′,by means of motor position and velocity closed loop.For higher performance of the measurement and control to 2-dimensional test,used a round inductive synchronous transducer fixed on airfoil axis measuring model actual angle and acting as feed back signal.This all position closed loop system can arrive at angle precision in ±0.0083°.To 3-dimonsional test,used an accelerometer fixed in model measuring in time the model actual attack angle,and preprocessed to test results,so that diminished those errors as a consequence of the aeroelastic angle.