Vk. Garg et Re. Gaugler, LEADING-EDGE FILM-COOLING EFFECTS ON TURBINE BLADE HEAT-TRANSFER, Numerical heat transfer. Part A, Applications, 30(2), 1996, pp. 165
A three-dimensional Navier-Stokes code has been used to study the effe
ct of spanwise pitch of shower-head holes and coolant to mainstream ma
ss flow ratio on the adiabatic effectiveness and heat transfer coeffic
ient on a film-cooled turbine vane. The mainstream is akin to that und
er real engine conditions with stagnation temperature 1900 K and stagn
ation pressure 3 MPa. It if found that with the ratio of coolant to ma
instream mass flow being fixed, reducing the spanwise pitch for shower
-head holes (P) from 7.5d to 3.0d, where d is the hole diameter, incre
ases the average effectiveness considerably over the blade surface. Ho
wever, when P/d = 7.5, increasing the coolant mass flow increases the
effectiveness on the pressure surface but reduces a oil the suction su
rface owing to coolant jet lift-off For P/d = 4.5 or 3.0 such an anoma
ly does not occur within the range of coolant-to-mainstream-mass-flow
ratios analyzed. In all cases, adiabatic effectiveness and heat transf
er coefficient are highly three-dimensional.