SCALING OF THE TURBULENT BOUNDARY-LAYER ALONG A FLAT-PLATE ACCORDING TO DIFFERENT TURBULENCE MODELS

At sufficiently large Reynolds number the turbulent boundary layer alo ng a flat plate under zero pressure gradient can be split up in an inn er and outer layer. The classical theory says that a law-of-the-wall h olds in the inner layer, and a defect law in the outer layer. It is sh own that Four different types of commonly used turbulence models (an a lgebraic, k-epsilon, k-omega and a differential Reynolds-stress model) all reproduce the classical similarity scalings for Re-theta above ab out 10(4). This was verified by numerically solving the turbulent boun dary-layer equations for Reynolds numbers (based on the momentum-loss thickness) in between 300 and 5 x 10(7). The boundary-layer solution i n the outer layer is shown to converge to the similarity solution of a defect-layer equation. NI turbulence models considered give a wall fu nction and defect law that is close to Direct Numerical Simulations of Spalart (1988) and new high-Reynolds-number experiments by Fernholz e t al. (1995). An exception is the algebraic model that gives a too thi n boundary layer. (C) 1998 Elsevier Science Inc. All rights reserved.