A turbulence model for buoyant and combusting flows
Abstract
Turbulent mixing and unmixing, including Rayleigh-Taylor and other instabilities are discussed. A two-fluid model of turbulence, and its relation to Prandtl's mixing-length hypothesis are outlined. Couette flows with and without curvature; channel flow with and without heating; and a combustion example are considered. The two-fluid model can be regarded as an extension of Prandtl's concept to include pressure-gradient-induced sifting. Unlike Prandtl, the model is not forced to replace differential equations by algebraic ones. Initial findings are encouraging: phenomena are explained which conventional turbulence models cannot comprehend, e.g., negative viscosity, flame-turbulence interactions.
- Publication:
-
NASA STI/Recon Technical Report N
- Pub Date:
- July 1985
- Bibcode:
- 1985STIN...8622909S
- Keywords:
-
- Buoyancy;
- Combustible Flow;
- Turbulence Models;
- Turbulent Flow;
- Two Fluid Models;
- Channel Flow;
- Couette Flow;
- Flow Stability;
- Mixing Length Flow Theory;
- Pressure Gradients;
- Fluid Mechanics and Heat Transfer