Three-dimensional laminar boundary layer in low-speed swirling flow with mass transfer

Similarity solutions are obtained for a low-speed three-dimensional laminar compressible boundary layer with swirl and mass transfer for a perfect gas characterized by realistic gas properties. The inadequacy of earlier solutions derived under the simplifying assumptions that viscosity exponent and Prandtl number are equal to unity is demonstrated. The governing equations are solved using the method of parametric differentiation combined with adequate quasi-linearization. It is shown that the effect of variation in the density-viscosity product ratio (for viscosity exponent other than unity) across the boundary layer on shear stress and heat-transfer parameters is appreciable only at low wall temperature, which indicates that the linear viscosity-temperature relation (viscosity exponent equal to unity) does not hold at low wall temperature. This variation entails a point of inflection in swirl velocity and total enthalpy profiles. For injection, swirl velocity and total enthalpy profiles exhibit a point of inflection even for a constant density-viscosity product.