Effect of angle of approach of the forced flow on the mixed convection heat transfer in air from an infinite isothermal horizontal cylinder

The laminar combined convection heat transfer from an infinite isothermal horizontal circular cylinder where the forced flow can attack the cylinder at different angles from 0° (assisting flow) to 180° (opposing flow) was studied and solved numerically. The study covered a wide range of the Grashof number from 100 to 1.69 × 106 and the Reynolds number from 40 to 300, while keeping the Prandtl number constant at Pr = 0.7.A mathematical model was constructed and solved using the Patankar-Splading Technique. A more accurate definition of the effective Reynolds number is obtained instead of the pervious definitions .The present work studies the effect of the angle of attack at different Reynolds and Grashof numbers on the Nusselt number and a correlation for the Nusselt number was obtained. © Faculty of Engineering Alexandria University, Egypt.