High-speed spiked body flows or flows similar to them can appear in a variety of aerospace applications, such as antisymmetric jet inlets with conical centrebody, ballistic missile drag reduction by spike, plasma or hot-gas injection, parachutes for pilot ejection capsules, or the ablation phenomenology associated with reentry problems. It is well known that both steady and unsteady flows can appear over spike body geometries depending on the spike length and the applied flow conditions. The driving mechanism of the unsteady flow mode pulsation arising over axisymmetric spiked bodies has been analyzed by using computational fluid dynamics as a tool. Laminar, axisymmetric flow at Mach 2.21 and Reynolds number (based on the blunt-body diameter) of 0.12 x 106 was simulated by a spatially and temporally second-order-accurate finite volume method. The model geometry was a forward facing cylinder of diameter D equipped with a spike of length L/D = 1.00. After reviewing previous pulsation hypotheses, the numerical results were analyzed in detail. A new driving mechanism was proposed, its main features being the creation of a vortical region in the vicinity of the foreshock-aftershock intersection causing mass influx into the dead-air region, the existence of supersonic flow within the dead-air region, the liftoff of the shear layer from the spike tip, and the collision of the recirculated and penetrating flows within the expanded separated region.
Driving mechanisms of high-speed unsteady spiked body flows, Part 1: Pulsation mode
Instationäre Überschallströmung an Rotationskörpern mit Spike, Teil 1: Pulsierende Strömung
AIAA Journal ; 42 , 1 ; 95-106
2004
12 Seiten, 23 Bilder, 29 Quellen
Article (Journal)
English
FLUID DYNAMICS - Driving Mechanisms of High-Speed Unsteady Spiked Body Flows, Part 1: Pulsation Mode
Online Contents | 2004
|Driving mechanisms of high-speed unsteady spiked body flows, Part 2: Oscillation mode
Tema Archive | 2004
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