ABSTRACT
A detailed numerical study on the film cooling of a corrugated surface through a single slot has been presented in this paper. The effects of the blowing ratio, density ratio (DR), and injection angle on the film cooling of the corrugated surface are discussed. Numerical simulations are carried out over a wide range of DRs ranging from 0.2 to 5.0 at a fixed mainstream Reynolds number of 1.5 × 105, three blowing ratios of 1, 2, and 3, and five injection angles ranging from 30° to 90°. Results show that the velocity profile on a corrugated surface is strongly influenced by the injection of the secondary fluid. It is observed that the film cooling effectiveness of the corrugated surface increases monotonically with an increase in the blowing ratio. The density ratio and injection angle also have a strong influence on the film cooling.
Nomenclature
a | = | amplitude of waviness of the corrugated surface, m |
D | = | slot width, m |
DR | = | density ratio, |
FC | = | film cooling |
FH | = | film heating |
M | = | blowing ratio, |
Re | = | Reynolds number based on mainstream flow, |
T | = | absolute temperature, K |
TR | = | temperature ratio, |
U | = | horizontal velocity, m/s |
V | = | vertical velocity, m/s |
X | = | streamwise coordinate, m |
Y | = | spanwise coordinate, m |
α | = | injection angle, in degrees |
η | = | adiabatic film cooling effectiveness, |
ρ | = | density, kg/m3 |
μ | = | dynamic viscosity, Pa-s |
λ | = | characteristic length of the corrugated surface, m |
Subscripts | = | |
avg | = | average |
cl | = | centerline |
in | = | inlet |
ms | = | mainstream |
sec | = | secondary |
w | = | wall |
Nomenclature
a | = | amplitude of waviness of the corrugated surface, m |
D | = | slot width, m |
DR | = | density ratio, |
FC | = | film cooling |
FH | = | film heating |
M | = | blowing ratio, |
Re | = | Reynolds number based on mainstream flow, |
T | = | absolute temperature, K |
TR | = | temperature ratio, |
U | = | horizontal velocity, m/s |
V | = | vertical velocity, m/s |
X | = | streamwise coordinate, m |
Y | = | spanwise coordinate, m |
α | = | injection angle, in degrees |
η | = | adiabatic film cooling effectiveness, |
ρ | = | density, kg/m3 |
μ | = | dynamic viscosity, Pa-s |
λ | = | characteristic length of the corrugated surface, m |
Subscripts | = | |
avg | = | average |
cl | = | centerline |
in | = | inlet |
ms | = | mainstream |
sec | = | secondary |
w | = | wall |