Vortex breakdown simulationIn this paper, steady, axisymmetric inviscid, and viscous (laminar) swirling flows representing vortex breakdown phenomena are simulated using a stream function-vorticity-circulation formulation and two numerical methods. The first is based on an inverse iteration, where a norm of the solution is prescribed and the swirling parameter is calculated as a part of the output. The second is based on direct Newton iterations, where the linearized equations, for all the unknowns, are solved simultaneously by an efficient banded Gaussian elimination procedure. Several numerical solutions for inviscid and viscous flows are demonstrated, followed by a discussion of the results. Some improvements on previous work have been achieved: first order upwind differences are replaced by second order schemes, line relaxation procedure (with linear convergence rate) is replaced by Newton's iterations (which converge quadratically), and Reynolds numbers are extended from 200 up to 1000.
Document ID
19870057660
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Hafez, M. (California Univ. Davis, CA, United States)
Ahmad, J. (California, University Davis, United States)
Kuruvila, G. (California Univ. Davis, CA, United States)
Salas, M. D. (NASA Langley Research Center Hampton, VA, United States)