Combined Experimental and Numerical Diagnostics for Near-field Flow around a Supersonic Flight Model

Abstract

A system for evaluating the near-field pressure distribution around a supersonic flight model by combining experimental and numerical diagnostics has been developed. Experimental measurement is conducted using a ballistic range with four kinds of axi-symmetric flight models. Schlieren flow visualization is recorded using a high-speed framing camera and near-field pressure histories are measured using piezoelectric pressure transducers flush-mounted on the surface of flat plates in the test section. The numerical diagnostics is done using FaSTAR, a numerical simulation tool developed by the Japan Aerospace Exploration Agency (JAXA). The experimental and numerical data are compared to each other, and the numerical results well validated. Based on the numerical results, it becomes possible to estimate the accuracy of experimental conditions including the flight path and angle of attack, which cannot readily be determined only from experimental data, and to discuss the relationship between peak overpressure and aerodynamic performance. Satisfactory agreement between the experimental and numerical results at a flight Mach number of 1.66 ± 0.02 and important insights related to rear boom strength are obtained.

Validation of measurement accuracy for near-field pressure around supersonic projectiles in a ballistic range

“…Near-field pressure measurement experiments in a ballistic range were initially conducted by NASA in the 1960s [17]. Since then, the experiments have been performed by many researchers in universities and at NASA [16,[18][19][20]. A ballistic range at the Institute of Fluid Science, Tohoku University was constructed in 2002.…”

“…In ballistic range experiments, the near-field pressure is generally measured by a flash-mounted pressure transducer in a plate [16,18,19]. In this case, shock waves generated from a free-flight projectile are reflected and diffracted at the plate, and these reflected/diffracted shock waves interfere with the measured pressure waveforms.…”