DOI: 10.1615/TSFP7
COMPRESSION OF A TUMBLING VORTEX: A LES AND PANS STUDY
要約
In this paper we report on parallel LES (Large Eddy
Simulation) and PANS (Partial-Averaged Navier-Stokes)
study of the flow and turbulence in the process of the
tumbling vortex generation and their response to the
consequently imposed compression. Reference database
was provided by Borée et al. (2002) who designed a square-piston
compression machine to investigate experimentally
the generation and breakdown of a tumbling motion. The
computational approach whose validation represents the
main objective of the present work is the so-called PANS
method, proposed recently by Girimaji (2006), which
provides a seamless transition from Unsteady RANS to the
direct numerical solution (DNS) as the unresolved-to-total
ratios of kinetic energy and its dissipation are varied.
Whereas the results obtained by both methods exhibit
reasonable agreement of the mean velocity field with
reference database during both the intake and compression
strokes, the predicted turbulence enhancement during the
compression stroke is somewhat retarded.