Discussions of some myths and concerned practices of film cooling research

摘要: Abstract This paper focuses on discussing four myths and concerned conventional practices of film cooling research guided by a series computational simulations. The issues that have been discussed include: (a) the effectiveness (φ) is given constant (0.6) to calculate heat flux ratio HFR = q ″ / o between film-cooled no-film cases; (b) adiabatic wall temperature driving cooling; (c) transfer coefficient can be obtained from an isoenergetic experiment (Tj = Tg); (d) using heated surface provide simplified approach simulate film-cooling condition. result shows not always (i.e. Taw larger than Tw), but does act well as reference in correctly predicting direction giving positive coefficient. Using value for φ questionable may lead un-realistic or false HFR. equation was theoretically exact error up 20%. A revised provided this paper. dominant energy passage turbine airfoil hot combustion gas flows into airfoil; therefore, employing boundary condition with hotter main stream flow cold injection actual found fundamentally questionable. conjugate simulation includes internal reversed blade gives negative possible, due conduction downstream region near hole cooler region.