Radiative energy transfer in compressible turbulence
Francoise Batailley? and Ye Zhouy
Institute for Computer Applications in Science and Engineering
NASA Langley Research Center, Hampton, VA 23681, USA
Laboratoire de Mecanique des Fluides et d'Acoustique, URA CNRS 263 36, av. Guy de Collongue, 69130 ECULLY, FRANCE
This Letter investigates the compressible energy transfer process. We extend a methodology developed originally for incompressible turbulence and use databases from numerical simulations of a weak compressible turbulence based on Eddy-DampedQuasi-Normal-Markovian (EDQNM) closure. In order to analyze the compressible mode directly, the well known Helmholtz decomposition is used. While the compressible component has very little influence on the solenoidal part, we found that almost all of compressible turbulence energy is received from its solenoidal counterpart. We focus on the most fundamental building block of the energy transfer process, the triadic interactions. This analysis leads us to conclude that, at low turbulent Mach number, the compressible energy transfer process is dominated by a local radiative transfer (absorption) in both inertial and energy containing ranges.
?The research was supported for the first author by the French Government, Ministere des Affaires
yThis research was partially supported by the National Aeronautics and Space Administration under NASA Contract No. NAS1-19480 while the first and second authors were in residence at the Institute for Computer Applications in Science and Engineering (ICASE), NASA Langley Research Center, Hampton, VA 23681-0001.