Accession Number : ADA259464


Title :   Numerical Solution of Three-Dimensional Unsteady Viscous Flows


Descriptive Note : Final rept. 1 Dec 88-30 Nov 92,


Corporate Author : GEORGIA INST OF TECH ATLANTA SCHOOL OF AEROSPACE ENGINEERING


Personal Author(s) : Sankar, Lakshmi N ; Park, Wam-Gyu


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a259464.pdf


Report Date : Dec 1992


Pagination or Media Count : 104


Abstract : The behavior of free shear layers within ramjet dump combustors is studied through the numerical solution of unsteady compressible Navier-Stokes equations. Three configurations are considered: (a) a short combustor with an open downstream boundary, (b) a long combustor with an open downstream boundary, and (c) a short combustor with a partially blocked downstream boundary. Vorticity contours of the computed flow fields in all the three cases reveal oscillations of the shear layer, roll up and shedding of organized vortices. A Fourier analysis of the computed flow fields indicates that the natural acoustic frequency of the system, and the natural shear layer instability frequency are the two dominant frequencies of the flow field. It is also observed that the boundary conditions play a crucial role in the behavior of the combustor flow field.


Descriptors :   *COMBUSTORS , *UNSTEADY FLOW , *NAVIER STOKES EQUATIONS , FREQUENCY , ROLL , LAYERS , FLOW FIELDS , ACOUSTICS , VISCOUS FLOW , CONTOURS , FOURIER ANALYSIS , RECREATION , INSTABILITY , OSCILLATION , EQUATIONS , BEHAVIOR , CONFIGURATIONS , VORTICES , BOUNDARIES , THREE DIMENSIONAL


Subject Categories : Fluid Mechanics


Distribution Statement : APPROVED FOR PUBLIC RELEASE