Numerical Analysis of Dusty Supersonic Flow Past Blunt Axisymmetric Bodies


Book Description

An inverse method was developed for treating gas-particle supersonic flow past axisymmetric blunt bodies. This method is based on two transformations (von Mises and an additional one), which are convenient for determining the shock-layer flow fields and the body shapes. In using the present method, the pure gas flow fields around spheres were first solved numerically for the freestream Mach numbers = 10, 6, 4, 3, 2 and 1.5. These were found to be in very good agreement with the available results of Van Dyke and Gordon. Then the gas-solid-particle flow in the shock layer around blunt bodies (nearly spheres) were solved for the freestream Mach numbers = 10 and 1.5, with freesteam loading ratios = 0, 0.2, 0.5 and 1.0 and particle diameters 1, 2, 5 and 10 micrometers respectively.







A Numerical Investigation of Subsonic and Supersonic Flow Around Axisymmetric Bodies


Book Description

A computational fluid dynamics (CFD) approach to predicting high- speed aerodynamic flow fields of interest to the U.S. Army Research Laboratory (ARL) has been carried out The aerodynamic problems of particular interest are: (1) supersonic flow past the aftbody of projectiles with base mass injection, (2) supersonic flow past the M549 projectile, and (3) subsonic, transonic, and supersonic flow past an M864 projectile with base bleed and wake combustion. The commercially available FLUENT (Fluent, Inc. FLUENT. Version 5.1.1, Lebanon, NH, 1999.) CFD code was utilized. The computational effort supports an ongoing ARL- sponsored experimental investigation. Of particular interest in the present investigation is the careful characterization of the various turbulence models employed in the CFD code. Additionally, the ease of use and set-up as well as the computational time will be described. An experimental effort (Dutton, J. C., and A. L. Addy. 'Fluid Dynamic Mechanisms and Interactions Within Separated Flows'. U.S. Army Research Office Research Grant DAAH04-93-G-0226 and the Department of Mechanical and Industrial Engineering, University of illinois, Urbana-Champagne, Urbana, IL, August 1998.) consisting of detailed laser Doppler velocimeter (LDV), particle image velocimeter (PIV), and high-speed wall pressure measurements has been made in axisymmetric and planar subsonic and supersonic flows with embedded separated regions. The present work seeks to predict similar flow fields computationally and to address areas of agreement and disagreement.




Numerical Methods for Predicting Subsonic, Transonic and Supersonic Flow


Book Description

The methods available for numerical computation of subsonic, transonic and supersonic flows are discussed and comments are included on the characteristics of the popular methods. Both inviscid and viscous computation methods are addressed. A brief account of the basic approaches for developing methods initiates the discussion. Also included is a general summary of the state of the art of computational methods along with suggested approaches for solving problems in each area. The report is included with recommendations for future study and development. (Author).




Supersonic Flow Past a Family of Blunt Axisymmetric Bodies


Book Description

Some 100 numerical computations have been carried out for unyawed bodies of revolution with detached bow waves. The gas is assumed perfect with y=5/3, 7/5, or 1. Free-stream Mach numbers are taken as 1.2, 1.5, 2, 3, 4, 6, 10, and [infinity symbol]. The results are summarized with emphasis on the sphere and paraboloid.




Numerical Simulation of Viscous Shock Layer Flows


Book Description

The book is concerned with mathematical modelling of supersonic and hyper sonic flows about bodies. Permanent interest in this topic is stimulated, first of all, by aviation and aerospace engineering. The designing of aircraft and space vehicles requires a more precise prediction of the aerodynamic and heat transfer characteristics. Together with broadening of the flight condition range, this makes it necessary to take into account a number of gas dynamic and physical effects caused by rarefaction, viscous-inviscid interaction, separation, various physical and chemical processes induced by gas heating in the intensive bow shock wave. The flow field around a body moving at supersonic speed can be divided into three parts, namely, shock layer, near wake including base flow, and far wake. The shock layer flow is bounded by the bow shock wave and the front and lat eral parts of the body surface. A conventional approach to calculation of shock layer flows consists in a successive solution of the inviscid gas and boundary layer equations. When the afore-mentioned effects become important, implementation of these models meets difficulties or even becomes impossible. In this case, one has to use a more general approach based on the viscous shock layer concept.