| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 854761 | Procedia Engineering | 2015 | 7 Pages |
Film cooling is one of the cooling techniques used in gas turbines to protect the blades from high temperature. The efficiency of gas turbine can be increased by increasing the inlet gas temperature. The present study aims at numerical investigation of adiabatic film cooling effectiveness over the cylindrical hole exit flat plate test model. The hole inclination angle of 20° with stream wise direction is considered. The test model has 35 film cooling holes arranged in two rows in a staggered configuration with the coolant hole length to diameter ratio of 5.4 and pitch to diameter ratio of 4. During the experimental analysis, the adiabatic film cooling effectiveness is found at five different blowing ratios in the range of 0.5 to 2.5 with the coolant to mainstream density ratio at 1.6. The laterally averaged film cooling effectiveness is calculated along the stream wise direction at these blowing ratios. The realizable k-epsilon turbulence model with enhanced wall function is used to solve the flow field. The CFD obtained results are validated with the experimental results at a blowing ratio of 1.0. Further, the CFD analysis is done for other blowing ratios in the range of 0.5 to 4.0 at density ratios of 1.6, 1.8 and 2.0. From the CFD results, the laterally averaged film cooling effectiveness is found to be increasing with the increase in blowing ratio up to 1.5 immediately downstream of the coolant holes. For the blowing ratios of 2.0 to 4, the adiabatic film cooling effectiveness is less immediately downstream of coolant holes up to x/d=15 and then increases with increase in the blowing ratios considered.
