The experimental determination of the local coefficient of surface friction in the turbulent boundary layer

In experimental studies of boundary-layer flows, the determination of the local coefficient of surface friction, Cf, is difficult. Various methods exist for the experimental determination of Cf. The investigations considered include studies conducted by Repik and Kuzenkov (1976), Vlasov (1973), and Kiril'tsev (1982). The results obtained in these studies show that Cf can be determined on the basis of the slope of the mean velocity in the viscous sublayer. A mathematical expression for Cf is considered. The discussed procedure for the determination of the local surface friction coefficient is based on the results of the thermoanemometric measurements of a profile of the mean longitudinal component of the flow rate in a turbulent boundary layer.