variavel0=<b>Wagner Machado Brasil</b> - wbrasil@serv.com.ufrj.br PEM/COPPE/UFRJ
<b>Jian Su</b> - sujian@lmn.con.ufrj.br PEN/COPPE/UFRJ
<b>Atila P. Silva Freire</b> - atila@serv.com.ufrj.br PEM/COPPE/UFRJ
<b>Abstract.</b> An inverse problem is solved for the estimation of upstream velocity profiles in an incompressible turbulent boundary layer over a smooth flat plate. The procedure is based on hot wire velocity measurements obtained at several different locations in the stream. The paper also presents a direct problem approach for the solution of the turbulent boundary layer equations. The direct approach resorts to a finite difference method and to the Cebeci-Smith turbulence model. The unknown upstream velocity profile is constructed by using the composite Coles’s law of the wall, law of the wake formulation. The friction velocity, von Karman constant, law of the wall constant, Coles’s wake-strength parameter and boundary layer thickness for the inicial profile are determined as unknown parameters by the Levenberg-Marquardt algorithm. The effects on solution about the location of the measurement station are examined. The results provided by the direct numerical simulation of the flow are also validated by data obtained through the hot wire anemometry technique in a low-speed wind tunnel. The estimated upstream velocity profiles are shown to compare favourably with hot wire anemometry measurements at the same location.
<b>Keywords.</b> Turbulence, Boundary layer, Inverse problem, Law of the wall.