화학공학소재연구정보센터
International Journal of Heat and Mass Transfer, Vol.52, No.13-14, 3118-3127, 2009
DNS study of pulsed film cooling for enhanced cooling effectiveness
Direct Numerical Simulation (DNS) of a pulsed film-cooling jet is presented to examine if pulsations of the coolant jet can enhance film-cooling effectiveness. Calculations are performed for a cylindrical jet inclined at 30 degrees. The jet pulsation is defined by the duty cycle (DC) and the Strouhal number (St), both of which are varied in this study. Baseline calculations are done for a steady blowing ratio of 1.5. Both frequency and duty cycle are observed to influence the cooling effectiveness. For a peak blowing ratio (M) of 1.5, pulsing with a St = 0.32 and DC = 0.5 is shown to reduce jet blow-off and improve centerline and spanwise-averaged effectiveness over the steady M = 1.5 case. (C) 2009 Elsevier Ltd. All rights reserved.