Thermal protection and drag reduction with use of spike in hypersonic flow

Motoyama, Noboru; Mihara, Ken; Miyajima, Ryo; Watanuki, Tadaharu; Kubota, Hirotoshi

doi:10.2514/6.2001-1828

Cited by 70 publications

(41 citation statements)

References 3 publications

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“…As a consequence, the technique has been the subject of extensive studies [14][15][16][17] . The main feature is the existence of a free stagnation point upstream of the orifice and most works have been carried out with the aim of designing shapes which would allow a steady flow to be maintained with ejected gas remaining attached to surface and turned through by nearly 180 degrees and free stagnation point fixed at a location in subsonic part of the flow behind detached curved shockwave typical of blunt body flows.…”

Section: Introductionmentioning

confidence: 99%

A novel means of dissipation of shock wave induced heat in a high speed flow

Zheng

Ahmed

2013

43rd Fluid Dynamics Conference

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The present paper proposes a novel means of heat dissipation in high speed flows where shock waves are formed by transferring heat along shock wave without transferring heat to body itself. This may be achieved through controlled oscillation of the shock wave without making it and the flow surrounding it unstable. From an experimental investigation on a 1/30 scale Apollo module using the supersonic wind tunnel at the Aerodynamics Laboratory of the University of New South Wales at Mach 3, counter flow jet injection and deploying into upstream flow behind the detached bow shock wave are formed to examine this concept. Results obtained are very promising and provide clear evidence to support this concept. The findings have the potential of achieving heat reduction with lower energy requirement. A greater understanding of the various interacting flow mechanism and optimization of different design parameters may open up the possibility of incorporating the concept into a viable and cost effective thermal protection systems for high speed vehicles.

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Section: Introductionmentioning

confidence: 99%

A novel means of dissipation of shock wave induced heat in a high speed flow

Zheng

Ahmed

2013

43rd Fluid Dynamics Conference

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“…However, because of the reattachment of the shear layer on the shoulder of the hemispherical body, the pressure near that reattachment point becomes large. Motoyama et al [15] have experimentally investigated the aerodynamic and heat transfer characteristics of conical, hemispherical, flat-faced aero-spike, and hemispherical and flat-faced disk attached to the aero-spike for a freestream Mach number 7, freestream Reynolds number 4x10 5 /m, for L/D = 0.5 and 1.0, and angle-of-attack 0 to 8 deg, where L is the spike length and D is the cylinder diameter. They found that the aero-disk spike (L/D = 1.0 and aero-disk diameter of 10 mm), has a superior drag reduction capability as compared to the other aero-spikes.…”

Section: Introductionmentioning

confidence: 98%

Heat Transfer Analysis over Disc and Hemispherical Spike Attached to Blunt-Nosed Body at Mach 6

Mehta¹

2011

17th AIAA International Space Planes and Hypersonic Systems and Technologies Conference

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Aero-spike attached to a blunt body significantly alters its flow field and influences aerodynamic drag at high speeds. The dynamic pressure in the recirculation area is highly reduced and this leads to the decrease in the aerodynamic drag. Consequently, the geometry of the aero-spike has to be simulated in order to obtain a large conical recirculation region in front of the blunt body to get beneficial drag reduction. Axisymmetric compressible NavierStokes equations are solved using a finite volume discretization in conjunction with a multistage Runge-Kutta time stepping scheme. The effect of the various types of aero-spike configurations on the reduction of aerodynamic drag is evaluated numerically at Mach 6 at a zero angle of attack. The computed density contours agree well with the schlieren pictures. Additional modification to the tip of the spike to get the different type of flow field such as formation of shock wave, separation area and reattachment point are examined flat-disk spike and hemispherical disk spike attached to the blunt nosed body. One of the critical heating areas is at the stagnation point of a blunt body, where the incoming hypersonic flow is brought to rest by a normal shock and adiabatic compression. Therefore the problem of computing the heat transfer rate near the stagnation point needs a solution of the entire flow field from the shock to the spike body. The bow shock distance ahead of the hemispherical and flat-disc is compared with the analytical solution and an agreement found between them. The influence of the shock wave generated from the spike is used to analysis the pressure distribution, the coefficient of skin friction and the wall heat flux facing the spike surface to the flow direction. The numerical analysis gives complete flow field information over the spike surface including the stand-off distance shock, sonic line, and velocity gradient along the surface of the spike. Nomenclaturelength of the spike M = Mach number q = wall heat flux Pr = Prandtl number p = pressure pa = ambient pressure s = distance along the surface of the spike R, S = vicous flux t = time u, v = velocity components 2 W = conservative vector γ = ratio of specific heats µ = viscosity ρ = density σ = normall stress µ = shear stress Subscripts w = wall ∞ = freestream condition

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“…An aerodisk mounted at the tip of a spike of a fixed length has the role of providing further reduction in both drag [14] and aerodynamic heating [15] over a wider range of Mach numbers [16] and incidence angles [12]. It can also compensate the drag reduction in cases when a shorter spike is necessary for design [10].…”

mentioning

confidence: 99%

“…It is known that the performance of spikes and the flow stability depend upon both the blunt body geometry and spike designs [20]. It is also proved that the spike's efficiency does not improve monotonically with the spike length [12,16,21] or the aerodisk size [15]. For more details about the physics of the flow around spiked bodies, the interested reader is advised to refer to the author's work in this respect [22].…”

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confidence: 99%

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Surrogate-Based Multi-Objective Aerothermodynamic Design Optimization of Hypersonic Spiked Bodies

Ahmed

Qin

2012

AIAA Journal

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In this work, a stability-constrained biobjective (aerodynamic drag and heating) design optimization for the hypersonic spiked bodies is conducted. The shape optimization includes both the forebody shape and the spike/ aerodisk shape through a generic parametric representation of the geometry. The NSGA-II multi-objective algorithm is coupled with the kriging surrogates that are constructed based on numerical solutions of laminar viscous flows around the geometries. The optimization reveals that the two objectives, minimum drag and minimum heating, are competing for spiked forebodies such that a set of Pareto front solutions are obtained. On the minimum-drag and maximum-aeroheating extreme, the optimal designs are characterized by highly blunt, nearly flat forebodies with the possibility of flow unsteadiness. On the other extreme, the optimal designs are commonly of slender forebodies with small bluntness. Between the two extremes, a variety of nondominant designs can be found.

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Thermal protection and drag reduction with use of spike in hypersonic flow

Cited by 70 publications

References 3 publications

A novel means of dissipation of shock wave induced heat in a high speed flow

A novel means of dissipation of shock wave induced heat in a high speed flow

Heat Transfer Analysis over Disc and Hemispherical Spike Attached to Blunt-Nosed Body at Mach 6

Surrogate-Based Multi-Objective Aerothermodynamic Design Optimization of Hypersonic Spiked Bodies

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