Abstract
Film cooling effectiveness downstream of one row of holes of 30 degree inclination angle was measured by using a steady-state thermochromic liquid crystal technique at blowing ratios of 0.5, 1.0, 1.5 and 2.0, respectively. Three kinds of dual-fanned holes which have the same expanded entrance width and the different expanded exit widths were tested. The configuration of only expanded entrance, but cylindrical exit hole, was tested to examine the effect of the expanded entrance on film cooling performance. The numerical simulation for the three expanded exit configurations was carried out explaining the mechanism of film cooling by the flow and thermal field. The only expanded entrance has a weak influence on film cooling effectiveness. The
Funding statement: This study was supported by the National Natural Science Foundation of China (Grant No. 51406124), Natural Science Foundation in Liaoning Province of China(2015020112).
Nomenclature
- Re
Reynolds number (=ud/v)
- M
blowing ratio (=ρcuc/ρgug)
- T
Kelvin temperature [K]
- t
centigrade temperature [°C]
- u
velocity [m/s]
- d
cylindrical hole diameter [m]
- L
length of hole [m]
- A
area [m2]
- w
spanwise width of hole
- P
pitch of hole[m]
- x
mainstream direction[m]
- y
spanwise direction[m]
- z
normal to cooled surface[m]
- Greek symbols
- v
kinematic viscosity [m2/s]
- ρ
density [Kg/m3]
film cooling effectiveness (
dimensionless temperature (
inclination angle of hole [
lateral expansion angle of hole [
- Subscripts
adiabatic wall
coolant
gas
total
average
entrance of hole
exit of hole
film hole
cylindrical hole
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