Theory of the hypersonic viscous shock layer at high Reynolds numbers and intensive injection of foreign gases

Gershbein, É. A.

doi:10.1016/0021-8928(75)90091-x

Cited by 13 publications

(5 citation statements)

References 5 publications

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“…Strong radiative processes from the shock layer ( Figure 4) that contribute significantly to the heating of the meteoroid body and vaporization process behind the shock layer have been extensively considered by several authors (Nemchinov et al, 1963;Stulov, 1972;Gershbein, 1974;Zel'dovich and Raizer, 2002). Additionally, radiation also affects the value of γ (Zel'dovich and Raizer, 2002) and consequently influences the shock layer thickness and mean free path by dissociation of molecules that initially might have passed through the shock front undissociated.…”

Section: Figurementioning

confidence: 99%

Physics of meteor generated shock waves in the Earth’s atmosphere – A review

Silber

Boslough

Hocking

et al. 2018

Advances in Space Research

105

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Shock waves and the associated phenomena generated by strongly ablating meteoroids with sizes greater than a few millimeters in the lower transitional flow regime of the Earth's atmosphere are the least explored aspect of meteor science. In this paper, we present a comprehensive review of literature covering meteor generated shock wave phenomena, from the aspect of both meteor science and hypersonic gas dynamics. The primary emphasis of this review is placed on the mechanisms and dynamics of the meteor shock waves. We discuss key aspects of both shock generation and propagation, including the great importance of the hydrodynamic shielding that develops around the meteoroid. In addition to this in-depth review, the discussion is extended to an overview of meteoroid fragmentation, followed by airburst type events associated with large, deep penetrating meteoroids. This class of objects has a significant potential to cause extensive material damage and even human casualties on the ground, and as such is of great interest to the planetary defense community. To date, no comprehensive model exists that accurately describes the flow field and shock wave formation of a strongly ablating meteoroid in the non-continuum flow regime. Thus, we briefly present the current state of numerical models that describe the comparatively slower flow of air over non-ablating bodies in the rarefied regime. In respect to the elusive nature of meteor generated shock wave detection, we also discuss relevant aspects and applications of meteor radar and infrasound studies as tools that can be utilized to study meteor shock waves and related phenomena. In particular, infrasound data can provide energy release estimates of meteoroids entering the Earth's atmosphere. We conclude with a summary of unresolved questions in the domain of meteor generated shock waves; topics which should be a focus of future investigations in the field.

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Section: Figurementioning

confidence: 99%

Physics of meteor generated shock waves in the Earth’s atmosphere – A review

Silber

Boslough

Hocking

et al. 2018

Advances in Space Research

105

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“…Curve 4 represents the thickness of the injection layer calculated in accordance with the formulas of [7] . The analytical solution of [7] has good accuracy for 0< 6 < _ _ 0 .1, but with increase in the injection strength (for 6>0 .1) it overestimates y,, -by approximately by 6% as compared with the experimental data and the …”

Section: Results Of Calculations In the Neighborhood Of The Stagnatmentioning

confidence: 86%

“…The main parameters governing the flow in the injection layer [6,7] are the relative mass flow rate G,,,(pw, vw) and the momentum density ratio 6 of the injected and oncoming gases, where pH, and Pw are the characteristic density and velocity in the injected gas …”

Section: Problem Formulation and Numerical Methods Of Solutionmentioning

confidence: 99%

“…Thus, a comparison of the approximate similitude relations and the numerical solutions makes it possible to clarify the range of applicability of these relations, while the similitude parameters proposed in [2,6,13] turn out to be useful in the processing of the results of numerical calculations .…”

mentioning

confidence: 98%

“…Similitude relations for the shock wave stand-off distance, the drag and friction coefficients, the convective and radiative heat transfer to impermeable bodies, which are of practical importance, have been obtained in the last few years on the basis of these solutions [2][3][4][5] . In the case of the intense subsonic injection of a foreign gas from the body surface, another small parameter appears, namely, the momentum ratio for the injected and oncoming gases [6,7] . In this case it is also possible to construct an asymptotic solution and to obtain, for example, the shape of the contact surface separating two flows [7] .…”

mentioning

confidence: 99%

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On the applicability of some approximate similitude laws in hypersonic aerodynamics

Pilyugin¹,

Talipov²,

Utyuzhnikov³

1994

Fluid Dyn

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The range of applicability of some similitude laws for heat transfer, friction and drag coefficients is discussed on the basis of numerical solutions of the complete viscous shock layer equations describing hypersonic flow past blunt bodies .The method of matched asymptotic expansions [1] is used widely in the theory of hypersonic flow past bodies ; this method enables one to solve simplified gasdynamic equations in the first terms of the expansion of the unknown functions in asymptotic series in terms of a small parameter [2][3][4] . Similitude relations for the shock wave stand-off distance, the drag and friction coefficients, the convective and radiative heat transfer to impermeable bodies, which are of practical importance, have been obtained in the last few years on the basis of these solutions [2][3][4][5] . In the case of the intense subsonic injection of a foreign gas from the body surface, another small parameter appears, namely, the momentum ratio for the injected and oncoming gases [6,7] . In this case it is also possible to construct an asymptotic solution and to obtain, for example, the shape of the contact surface separating two flows [7] .The results of asymptotic and numerical studies of supersonic viscous nonuniform wake-type flows past blunt bodies with and without gas injection from the body surface were reviewed in [8] .Since the convergence of asymptotic solutions in the general case of nonlinear gasdynamic equations has not been proved strictly from the mathematical standpoint, the problem of the accuracy and the applicability range of the approximate similitude relations thus obtained arises . In order to arrive at an answer to this problem, it would be well to carry out a systematic comparison with the results of either specifically designed aerodynamical experiments or numerical solutions of the more accurate (non-simplified) gasdynamic equations .In recent years a numerical method of solving the complete viscous layer equations has been developed [9] . This makes it possible to calculate the distributions of all the gasdynamic parameters in the shock layer adjacent to a blunt cone with or without gas injection from the body surface, in uniform and nonuniform oncoming streams [10][11][12] . Comparison of the numerical solutions for flow past a sphere and a blunt cone obtained by this method with the experimental data and other numerical and asymptotic solutions [10][11][12] shows that the method possesses high accuracy and requires less computation time than time-dependent methods for the Navier-Stokes equations . On the basis of the approximate asymptotic solutions, a general similarity law was derived in [13] for convective heat transfer to the side surface of a slender blunt body in laminar hypersonic flow, as well as for other gasdynamic parameters . The similitude laws for inviscid flow past blunt slender bodies and viscous flow past sharp slender bodies follow from this law as special cases .

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