LAMINAR BOUNDARY-LAYER SWIRLING FLOW WITH HEAT AND MASS-TRANSFER IN CONICAL NOZZLES AND DIFFUSERS

The flow and heat transfer for a steady axisymmetric laminar incompressible boundary layer swirling flow with mass transfer in a conical nozzle and a diffuser have been studied. The partial differential equations governing nonsimilar flow have been solved numerically using an implicit finite-difference scheme after transforming them into new coordinates having finite ranges. The results indicate that, both for the nozzle and diffuser, swirl exerts a strong influence on the longitudinal skin friction, but its effect on the tangential skin friction and heat transfer is comparatively small. In the case of the nozzle, even for a small value of the dissipation parameter at the inlet, the heat transfer rapidly increases near the end of the nozzle; whereas in the case of the diffuser, no such trend is observed. Suction increases the skin friction and heat transfer, but injection does the reverse. The results are found to be in good agreement with those of the local nonsimilarity and momentum integral methods except near the end of the nozzle or diffuser, but they differ appreciably from those of the local similarity method except near the inlet.