Effect of Hole Space Ratio on Effusion Cooling Performance

  • Khalid Faisal Sultan University of Technology, Baghdad, Iraq
Keywords: Hole diameter, h Heat transfer coefficient with film cooling, Heat transfer coefficient without film cooling, Thermal conductivity, Span wise hole spacing, time, Temperature, Coolant temperature, Initial temperature, Hot mainstream temperature, Wall temperature, Coolant velocity, Hot mainstream velocity, Film cooling effectiveness, Average film cooling effectiveness, Stream wise Average film cooling effectiveness, Density of air, Density of coolant air, Density of hot mainstream


The film cooling effectiveness and local heat transfer coefficient for different hole
space ratio have been experimentally investigated on a flat plate in the current study. The
investigations were done by using a single test transient IR thermography technique. Three
models of staggered holes arrangement are investigated. ). Each model is provided with five
columns of holes, these models are arranged with staggered row holes. The holes diameter is
4mm, the longitudinal distance (X/D) is 10, and the span distance between two neighboring
holes (S/D) are 3, 5, and 7 respectively. The attitude of the holes is fixed at inclination angle
(θ = 30º ). The blowing ratios, cold to hot air flow ratio, have been changed three times (BR=
0.5, 1.0, and 1.5) during the experimental program. The experimental investigation showed
that the thermal performance decreases as the space ratio (S/D) increases for all blowing
ratios, and the film cooling effectiveness decreases as the blowing ratio increases for all the
three models.