The Problem of Pneumatic Pressure Lag: Part 2—Unsteady Flow in a Tubing System Closed at One End

Abstract

The results of the steady-state analysis presented in Part 1 are applied to a quasi-steady analysis isothermal flow in constant diameter tubes (with straight-through unions at the extremities) connected to a closed sensing volume. The ranges of transient pressure inputs and geometric variables were chosen to simulate typical missile pressure sensing systems. The effect of high inlet temperature during descent was not studied, all tests being at room temperature. The correlation of theory with experiment for three types of input (impulse, continuous, and shock) is shown to be quantitative over the range of variables studied. It is concluded that the empirical analysis presented herein provides an adequate working theory for pressure lag during transient flight.