Extracting accurate supersonic flight data for arotating hemisphere with offset Pitot tubes

摘要

Accurately determining aerodynamic attitude and velocity in supersonic flight with minimal instrumentation presents a large challenge. Determining this information on a rotating hemisphere is even more difficult. However, two offset and recessed Pitot tubes can provide flight pitch and yaw angles and Mach number with much lower uncertainty than traditional ground-based telemetry. Analytical corrections for tube temperature grradients, bending, crimping, and time-dependent pressures changes are presented. Bergh-Tijdeman wave propagation theory is coupled with oblique shock theory to produce Δα, Δβ < |0.5°| and ΔM < |0.02| uncertainties after post-flight data processing. A prerequistive for this approach is for the angle of rotation B to be independently known to within ±0.5 degrees and the height within 100 feet.