摘要:

An explicit three-dimensional, finite-volume Navier-Stokes solver with finile-rate H2/air combustion kinetics has been developed and calibrated to accurately and efficiently compute installed engine performance for complete single-stage-rocket (SSR) configurations. The Navier-Stokes formulation directly couples the global fluid dynamic, species continuity and transport equations for turbulent kinetic energy and dissipation resulting in increased solution robustness and accuracy. Comparisons of predicted and measured installed performance quantities are made for an SSR plug-nozzle configuration. Pretest installed performance predictions for embedded bell-nozzle vehicles are also included.

ISSN:1061-8562    

DOI:10.1080/10618569408904485

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Finite difference like discretizations are developed for the time dependent Navier-Stokes equations and the thermal energy equation. The flow is assumed to be thermally expandable, that is, the density varies only with temperature. A new pointwise first order upwind scheme for convection is presented which is of nonnegative type. Also presented are new approaches to reconstructing the velocity vector field from the covolume primitive variables. The resulting difference equations reproduce linear flow fields.

ISSN:1061-8562    

DOI:10.1080/10618569408904486

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

This research seeks to increase our understanding on the laminar-turbulent transition under an external body force. Direct numerical simulation by the spectral method with a weak formulation is used to solve the transient 3-D Navier-Stokes equations. Initial disturbances consist of the finite-amplitude 2-D Tollmien-Schlichting wave and two 3-D oblique waves. Competitions among different modes were computed during transition for different Richardson numbers.

ISSN:1061-8562    

DOI:10.1080/10618569408904487

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

This study intends to improve the predictability of the existing second-order closure turbulence models without tuning the model constants. For this purpose, a Reynolds stress model with a cross diffusion of κ in theϵequation is derived based on the physically more realistic assumption that small turbulent eddies can be anisotropic. The proposed Reynolds stress model differs from the existing Reynolds stress model in two aspects; an anisotropic dissipation model,, is adopted, and an additional cross diffusion term,Cϵ 3ϵ/ κ ∂(κ2/ ϵ ∂κ/∂ Xt)/∂ Xtis included in theϵequation. The proposed Reynolds stress turbulence model (RSMX), the existing Reynolds stress model (RSM) and a two-equation eddy viscosity model, theκ - ϵmodel, are then tested in three turbulent free shear flows, namely plane jet, round jet, and plane mixing layer flows. It is shown that the proposed RSMX of turbulence model performs better than the existing turbulence models in all the three free shear flows concerned.

ISSN:1061-8562    

DOI:10.1080/10618569408904488

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor