Abstract
Film cooling performances of laidback hole and laidback fan-shaped hole have been investigated using transient liquid crystal measurement technique. For film cooling of laidback hole, the increase of inclination angle reduces the film cooling effectiveness under small blowing ratio, while produces better film coverage and higher film cooling effectiveness under larger blowing ratios. Heat transfer coefficient is higher in the upstream region of laidback hole film cooling with large inclination angle, while laidback hole with small inclination angle has relatively higher heat transfer coefficient in the downstream region. The increase of inclination angle reduces the film cooling effectiveness and heat transfer coefficient of laidback fan-shaped hole film cooling, especially in the upstream region. Increase of inclination angle is beneficial to the thermal protection of laidback hole film cooling under large blowing ratio. Film hole with large inclination angle has larger discharge coefficient due to smaller aerodynamic loss in the hole.
Correction Note
Correction added after online publication June 2, 2016: The funding information was updated after ahead of print publication. “Natural Science Basic Research Plan in Shaanxi Province of China (Grant No. 2016JQ5056)” was supplied.
Funding statement: The authors acknowledge gratefully the financial support from Natural Science Basic Research Plan in Shaanxi Province of China (Grant No. 2016JQ5056), National Natural Science Foundation of China (Grant No. 51306152), Aeronautical Science Foundation of China (Grant No. 2014ZB53023), and Fok Ying Tung Education Foundation of China (Grant No. 141053).
Nomenclature
square root of thermal diffusivity
specific heat, [
discharge coefficient
film hole inlet diameter, [
heat transfer coefficient, [
momentum flux ratio (=
pressure, [
specific heat flux, [
Reynolds number (=
time, [
temperature, [
velocity, [
streamwise coordinate, [
spanwise coordinate, [
normal coordinate, [
- Greek symbols
inclination angle, [
film cooling effectiveness
density, [
molecular viscosity, [
thermal conductivity, [
- Subscripts
adiabatic wall
film ejection
mainstream
initial
surface
wall
without film ejection
- Abbreviation
- LBH
Laid-back hole
- LBFH
Laid-back fan-shaped hole
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