The turbulent heat flux in low Mach number flows with large density variations

Conference · Fri Jan 01 00:00:00 EST 1988

OSTI ID:5363519

O'Rourke, P J; Collins, L R

A transport equation has been derived which is the difference between the volume- and mass-averaged velocities and is simply related to the turbulent heat flux phi/sup h/. Using this equation and an assumption analogous to the drift flux approximation of two-phase flow modeling, an algebraic closure relation for phi/sup h/ that exhibits fluxes due to directed transport proportional to -del anti p and due to gradient transport proportional to -del Tau has been obtained. Much work remains to be done before the model can be used in predictive calculations of low Mach number flows with large density variations. The transport equation involves an additional scalar b that is a measure of the density fluctuations. An equation for b must be derived and terms in it modeled. We hope to use the transport equation and b-equation in conjunction with a k - anti epsilon turbulence model. The k- and anti epsilon- equations must be reexamined to see that modifications are needed when the flows have large density variations. When mass transport is important, such as in many combustion problems, expressions for the turbulent mass flux must be developed.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 5363519
• Report Number(s): LA-UR-88-633; CONF-880250-1; ON: DE88006445
• Resource Relation: Conference: Transport processes in dispersed two-phase flows with applications to propulsion systems, Huntsville, AL, USA, 25 Feb 1988; Other Information: Portions of this document are illegible in microfiche products
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
DENSITY
FLOW MODELS
HEAT FLUX
PRESSURE GRADIENTS
FLAMES
MACH NUMBER
GASES
INTERNAL COMBUSTION ENGINES
EXPERIMENTAL DATA
K CODES
RAYLEIGH-TAYLOR INSTABILITY
TURBULENCE
TURBULENT FLOW
TWO-PHASE FLOW
COMPUTER CODES
DATA
ENGINES
FLUID FLOW
FLUIDS
HEAT ENGINES
INFORMATION
INSTABILITY
MATHEMATICAL MODELS
NUMERICAL DATA
PHYSICAL PROPERTIES
VELOCITY
420400* - Engineering- Heat Transfer & Fluid Flow