Published online by Cambridge University Press: 04 July 2016
The paper presents a method for the prediction of meanflow data (i.e. skin friction, velocity profile andshape parameter) for adiabatic two-dimensionalcompressible turbulent boundary layers at zeropressure gradient. The transformed law of the wall,law of the wake, the van Driest model for thecomplete inner region and a correlation between theReynolds number based on the boundary layer integrallength scale (ReΔ*.) and the Reynoldsnumber based on the boundary layer momentumthickness (Reθw) were used to predict themean flow quantities. The results for skin frictioncoefficient show good agreement with a number ofexisting theories including the van Driest II andthe Huang et al. Comparison with alarge number of experimental data suggests that atleast for transonic and supersonic flows, thevelocity profile as described by van Driest andColes is Reynolds number dependent and should not bepresumed universal. Extra information or perhaps abetter physical approach to the formulation of themean structure of compressible turbulent boundarylayers even in zero pressure gradient and adiabaticcondition, is required in order to achieve complete(physical and mathematical) convergence when it isapplied in any prediction methods.
Formerly assistant professor of TehranUniversity, Iran