Pressure and Dilatation Effects in High-Speed Turbulence
- 328 Downloads
This paper examines the pressure and dilatation effects in high-speed turbulence on the basis of direct numerical simulation (DNS) databases of three-dimensional compressible mixing layers at convective Mach numbers M c = 0.8, 1.1 and 1.2. Fluctuating pressure effects are found to be significant for local turbulence energy balance and scalar transport. However, due to its acoustic nature, fluctuating pressure is mainly responsible for energy redistribution rather than energy creation or destruction. Models for velocity- and scalar-pressure gradients are developed and tested, which give satisfactory agreement with DNS data. Eddy shocklets are observed at M c = 1.1 and above. Their effects are spatially and temporally localized but have been substantially over-predicted by all existing models.
KeywordsMach Number Direct Numerical Simulation Premix Flame Pressure Work Direct Numerical Simulation Data
Unable to display preview. Download preview PDF.
- Bray, K. N. C., Libby, P. A. and Williams, F. A. (1994) High-speed turbulent combustion, in Turbulent Reactive Flows (P. A. Libby and F. A. Williams, Ed.), Academic Press, pp. 609–638.Google Scholar
- Jones, W. P. (1994) Turbulence modelling and numerical solution methods for variable density and combusting flows, in Turbulent Reactive Flows (P. A. Libby and F. A. Williams, Ed.), Academic Press, pp. 309–374.Google Scholar
- Lin, C. C. (1953) On the stability of the laminar mixing region between two parallel streams in a gas, NACA Technical Note, No. 2887, pp. 1–50.Google Scholar
- Luo, K. H. and Sandham, N. D. (1994) On the formation of small scales in a compressible mixing layer, in Fluid Mechanics and its Applications: Direct and Large-Eddy Simulation I (P. R. Voke, L. Kleiser and J.-P. Chollet, Ed.), Kluwer Academic Publishers, 26, pp. 335–346.Google Scholar