Collected Works of H. S. Tsien (1938-1956)

The Transfer Functions of Rocket Nozzles

H.S. Tsien

(Daniel and Florence Guggenheim Jet Propulsion Center, California Institute of Technology, Pasadena, Calif.)

The transfer function is defined as the fractional oscillating mass flow rate divided by the fractional sinusoidal pressure oscillation in the rocket combustion chamber. This is calculated as a function of the frequency of oscillation. For very small frequencies, the transfer function is approximately 1 with a small “lead component.” For very large frequencies, the transfer function is considerably larger than 1, and is approximately 1 + (γM₁)^—1 where γ is the ratio of specific heats ...