Modification of the Algebraic Transition Model for Wall Roughness Effect Including a Rough Strip

Abstract

The contribution deals with the simulation of the laminar/turbulent transition on a rough wall. The algebraic transition model taking into account wall roughness according to Straka and Příhoda [8] was further extended for the effect of short rough strip near the leading edge. The proposed correlation was tested by means of incompressible flow over a flat plate covered by sand paper and around the NACA 0012 airfoil with a rough strip near the leading edge. The agreement with experiments is appropriate nevertheless the applicability of the correlation is limited due to the lack of relevant experimental results.

Comparison of Two Transition Models Modified for Low Free-Stream Turbulence

“…The governing equations for the compressible flow are given by the Favre-averaged Navier-Stokes equations completed by the EARSM turbulence model proposed by Hellsten [4], the model of turbulent heat transfer, and by the algebraic transition model (see Straka and Příhoda [1]). The transition model is based on the concept of different values of the intermittency coefficient in the boundary layer (i) and in the free stream (e).…”

“…Most of transition models are based on the algebraic and/or on the transport equation for the intermittency coefficient, see e.g. Straka and Příhoda [1] and Langtry and Menter [2]. Further, the three-equation k-kL- model based on the transfer of energy between non-turbulent and turbulent vortices is the pre-transitional and transitional part was proposed by Walters and Cokljat [3].…”

Modeling the influence of surface roughness on boundary layer transition

“…Such models always solely based on empirical correlations coming from experiment or DNS. Such models introduce either algebraic relations (Straka and Příhoda, 2010) or add one or more transport equations. A single additional equation was introduced by Suzen and Huang (2000) or in k-ω-γ model (Wang and Fu, 2009).…”

“…Apart from intensifying heat and momentum transfer, surface roughness also influences the boundary layer transition Dryden (1953). Modeling such influence can be done by again amending the transition criterion, which comes from experimental data (Mayle, 1991;Straka and Příhoda, 2020). This first approach has restricted applicability for cases with non-uniform or localized surface roughness regions.…”