Experimental assessment of a nonlinear turbulent stress relation in a complex reciprocating engine flow

Abstract

A nonlinear turbulent stress relationship, based on an explicit algebraic Reynolds stress closure, is compared against experimental data obtained in a swirl-supported, light-duty engine motored at constant speed. The model relationship is applied to measured mean velocity gradients and turbulence scales, and the predictions compared against the measured shear stress and normal stress anisotropy. Significant improvement over the linear stress relationship typically used in two-equation turbulence models is observed. Conditions under which the model predictions are poor are identified and the reasons for the poor performance discussed.