Pressure-containing correlations in variable density and turbulent reacting flows

✍ Scribed by P.H. Gaskell; A.K.C. Lau

• Publisher: Elsevier Science
• Year: 1988
• Tongue: English
• Weight: 329 KB
• Volume: 73
• Category: Article
• ISSN: 0010-2180
• DOI: 10.1016/0010-2180(88)90048-x

✦ Synopsis

NOMENCLATURE c scalar variable P pressure s possible source term t time ui ith velocity component V volume Xi ith spatial coordinate r position vector Greek P mass density c1 dynamic viscosity h exchange coefficient

Experimental measurements in variable density and reacting turbulent flows [l-6] show the existence of anomalous countergradient diffusion, that is, a turbulent flux is seen to be present which acts in the direction of increasing value of the mean quantity under consideration. In such a situation, conventional gradient transport type models are totally inadequate both conceptually and physically, because a negative exchange coefficient is implied. This short paper reopens the question as to the role played by pressure gradient terms in the countergradient diffusion process and queries the validity of some associated modeling assumptions.