Aerodynamic and Frequency Dependent Errors in an Air Blast Gage

摘要

Tests were conducted in the supersonic and hypersonic wind tunnel to determine the aerodynamic error due to mass flow around a pancake type gage. This air blast gage was used extensively to measure the transient side-on pressure generated by an explosive charge. Data on flat surfaces are also presented. The error due to mass flow is a function of both Mach number and Reynolds number. Error is largest near Mach one. Measurements of impulse on gages with various shapes of pulses are considered. If there is no negative phase, impulse is independent of the gage size; the negative phase results in a low value of impulse for a gage longer than 1/10 the length of the positive phase. (Author)