variavel0=<b>Ramiro Gustavo Ramirez Camacho</b> - rgramirez65@hotmail.com ITA- Instituto Tecnológico de Aeronáutica
<b>Nelson Manzanares Filho</b> - nelson@iem.efei.br Escola Federal de Engenharia de Itajubá
<b>Abstract.</b> The determination of drag coefficients in turbomachinery cascades always represents difficulties, this is specially true when pressure integration and superficial friction technique is used. This technique presents uncertainties due to the numeric integration process and to the medium flow direction determination on the cascade, which depends on the calculated value of circulation around airfoil. In front of that difficulty, alternatives to drag calculation are presented, based on boundary layer’s momentum thickness in the separation point, and separation velocity. It is possible to determinate the drag coefficient in the separation region through Speidel(1954) and Schlichting(1969) correlations. Other methodology for the separation region’s drag calculation is based on normal velocities distributions or flow injection quantified by Hayashi and Endo(1977) semi-empirical correlations. For the potential flow calculation Hess and Smith(1966) panels method is used with modifications on boundary conditions as a way to enter viscous effects through transpiration technique and through flow injection in the separation region, Ramirez et al (2001). In this work different drag calculus methodologies results are presented and compared with experimental data found on literature, where good concordance is obtained.
<b>Keywords.</b> drag, viscous /inviscid interaction, boundary layer, turbomachinery cascades, panels method.