Numerical investigation on conjugate cooling performance of double swirl cooling at vane leading edge

Numerical investigations are conducted on the conjugate cooling performance of leading edge double swirl cooling (DSC) method coupled with simplified film cooling. The target channel of DSC method is composed of two partially overlapping swirl channels. As a reference, a semicircular target channel (Imp) is also established. One row of 10 jet holes with the average jet Reynolds number of 15,000 and one row of 10 film holes at the stagnation region with an inclination angle of 30? are employed. Numerical simulations are conducted with five blowing ratios range from 1.0-3.0 under both adiabatic and conductive vane conditions to reflect the contribution of internal cooling on conjugate cooling performance. The basic flow features are illustrated. The coolant mass flow rate distribution, the internal mechanical energy losses and overall performance are compared. The film cooling performance is also compared and analyzed. Results show that, compared with Imp cases, the area average Nusselt number increases 44-49%, the mechanical energy losses increase 7-24% and the target channel overall performance increases 35-38% in DSC cases. Also compared with Imp cases, the area average conjugate film cooling effectiveness increases 5-12% and the area average contribution on the conjugate cooling performance increases 10-23% in DSC cases.