A Study on the Measurement for the Pitch Dynamic Stability Derivatives of Standard Dynamic Model

This paper presents the measuring method for dynamic stability derivatives in the pure pitching motion of a standard dynamic model using the free oscillation technique in the low-speed md tunnel. It was released for standard dynamic model to be oscillated without any excitations after initial displacement by the compressed air jet. Angular displacements were measured by the dynamic stability balance, and the data was processed to determine the pitch dynamic stability derivatives using the method of logarithmic decrement. Test results are compared with the one in the literature. It confirms the validity of experimental technique and data reduction procedure and it also shows the reliability for the stability derivatives up to 36 degrees of the angle of attack