Turbulence modeling in a hypersonic inlet

Ng, W. F.; Ajmani, Kumud; Taylor, Arthur C.

doi:10.2514/3.10271

Cited by 5 publications

(4 citation statements)

References 6 publications

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“…In the case of the P8 inlet, the pressure rose by a factor of 2 across the cowl shock, and an additional factor of 4 of compression was obtained by a compression wave system generated by the curvature of the cowl. Extensive experimental data were gathered by Gnos et al 9 Since then, several researchers 10,11 have performed two-dimensional Navier -Stokes simulations of these inlets, the earliest being Knight.…”

mentioning

confidence: 99%

Automated Design Optimization for the P2 and P8 Hypersonic Inlets

Shukla

Gelsey

Schwabacher

et al. 1997

Journal of Aircraft

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An automated design methodology incorporating industry-standard Navier -Stokes codes and a gradient-based optimizer has been developed. This system is used to redesign the well-known NASA P2 and P8 hypersonic inlets. First, the Navier -Stokes simulations of the original P 2 and P8 inlet designs are validated using numerical convergence studies and comparison with wind-tunnel experimental data for the original inlets published by NASA in the early 1970s. Second, the P 2 and P8 inlets are redesigned with the objective of canceling the cowl shock (and, in the case of the P8 inlet, the additional cowlgenerated compression) at the centerbody by appropriate contouring of the centerbody boundary. The original inlets were intended to achieve these same objectives, but detailed experimental measurements indicated that a substantial re ected shock system was present. The choice of the objective function, which is used to drive the optimization, has a signi cant impact on the nal design. Several different formulations for the objective function have been employed, and improvements of 60 -90% in the objective function have been achieved. This automated design system represents one of the rst successful combinations of numerical optimization methods with Reynolds-averaged Navier -Stokes uid dynamics simulation for high-speed inlets, and demonstrates a new area in which high-performance computing may have considerable impact on problems of military and industrial signi cance. Nomenclature

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mentioning

confidence: 99%

Automated Design Optimization for the P2 and P8 Hypersonic Inlets

Shukla

Gelsey

Schwabacher

et al. 1997

Journal of Aircraft

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“…It was then reflected from the cowl and interacted again with the centerbody turbulent boundary layer before it left the inlet. 4 also reported the presence of a separation bubble when they used the Baldwin-Lomax model. This indicates that the Baldwin-Lomax model fails in regions of shock-wave/boundary-layer interaction at hypersonic speeds.…”

Section: Resultsmentioning

confidence: 99%

Comparative study of turbulence models in predicting hypersonic inlet flows

Kapoor

Anderson

Shaw

1992

28th Joint Propulsion Conference and Exhibit

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A numerical study was conducted to analyze the performance of different turbulence models when applied to the hypersonic NASA P8 inlet. Computational results from the PARC21) code, which solves the full two-dimensional Reynolds-averaged Navier-Stokes equations, have been compared with experimental data. The zero-equation models considered for the study were the Baldwin-Lomax model, the Thomas model, and a combination of the Baldwin-Lomax and Thomas models; the two-equation models considered were the Chien model, the Speziale model (both low Reynolds number), and the Launder and Spalding model (high Reynolds number). The Thomas model performed best among the zero-equation models, and predicted good pressure distributions. The Chien and Speziale models compared very well with the experimental data, and performed better than the Thomas model near the walls.

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“…Kumar 1981;Hunter and Kent 1986;Reddy et al 1989;Gielda and Agarwal 1989;Povinelli 1990) or a turbulence kinetic energy one equation model (e.g. Ng et al 1989) when the flow becomes turbulent. The advantage of algebraic eddy viscosity models is their relative simplicity and straightforward implementation in the computational method used.…”

Section: Introductionmentioning

confidence: 99%

“…Povinelli 1990;Ng et al 1989;Marvin 1983) that proper turbulence modeling is important if computational fluid dynamics techniques are to be a viable tool for aerospace vehicle design and development. Several workers (e.g.…”

Section: Introductionmentioning

confidence: 99%

Shock waves and turbulence in a hypersonic inlet

1995

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Abstract.A numerical investigation for an axisymmetric hypersonic turbulent inlet flow field of a perfect gas is presented for a three-shock configuration consisting of a biconic and a cowl. An upwind parabolized Navier-Stokes solver based on Roe's scheme is used to compute an oncoming flow Mach number Moo = 8, temperature Too = 216 K, and pressure Poo = 5.5293 x 103 N/m 2. In order to assess the flow quantities, the interaction between shock and turbulence, and the inlet efficiency, three different flow calculations -laminar, turbulent with incompressible and compressible two-equation k-e turbulence models -have been performed in this work.Computational results show that turbulence is markedly enhanced across an oblique shock with step-like increases in turbulence kinetic energy and dissipation rate. This enhancement is at the expense of the mean kinetic energy of the flow. Therefore, the velocity behind the shock is smaller in turbulent flow and hence the shock becomes stronger. The entropy increase through a shock is caused not only by the amplification of random molecular motion, but also by the enhancement of the chaotic turbulent flow motion. However, only the compressible k-e turbulence model can properly predict a decrease in turbulence length scale across a shock. Our numerical simulation reveals that the incompressible k-e turbulence model exaggerates the interaction between shock and turbulence with turbulence kinetic energy and dissipation rate remaining high and almost undissipated far beyond the shock region. It is shown that proper modeling of turbulence is essential for a realistic prediction of hypersonic inlet flowfield. The performed study shows that the viscous effect is not restricted in the boundary layer but extends into the main flow behind a shock wave. The loss of the available energy in the inlet performance therefore needs to be determined from the shock-turbulence interaction. The present study predicts that the inlet efficiency becomes relatively lower when turbulence is taken into account.

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Turbulence modeling in a hypersonic inlet

Cited by 5 publications

References 6 publications

Automated Design Optimization for the P2 and P8 Hypersonic Inlets

Automated Design Optimization for the P2 and P8 Hypersonic Inlets

Comparative study of turbulence models in predicting hypersonic inlet flows

Shock waves and turbulence in a hypersonic inlet

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