Film cooling effectiveness from trenched shaped and compound holes

Adiabatic and conjugate cooling effectiveness analysis of a new hybrid scheme

“…They investigated the effect of film hole geometry and flow parameters on the film cooling performance. Amongst the advanced film hole configurations are: fan shaped film hole [6], laterally diffused hole [3], forward and lateral shaped hole [26], console film hole [23], laidback fan shaped hole [24], straight fan shaped hole [25], compound angle fan shaped hole (CAFSH) [5] and fan shaped with trench hole [1]. Eriksen and Goldstein [6] experimentally investigated the effect of the blowing ratio on the centerline film cooling effectiveness for injection film holes having a 35 inclination angle and lateral expansion angle of 10 at a distance of 1 d from the entrance of the film hole.…”

Film-cooling of cylindrical hole with downstream surface dielectric barrier discharge actuators

“…A layer of cool air is formed over the metal surface, thereby insulating the metal from the hot main stream flow and further reducing the metal temperature. However, the cooling film is destroyed in the downstream area of hole because of the counter rotation vortex pairs (CRVP), which are generated by the interacting between the jet flow from film-cooling hole and the main flow [7]. The CRVP enhances the mixing strength between the jet flow and the main flow, thus promoting jet flow lifting off from the metal surface and leading the main flow to enter into the bottom of jet flow, resulting in a bad film-cooing performance.…”

Influence of coolant injector configuration on film cooling effectiveness for gaseous and liquid film coolants

“…and found that the forwarded expanded holes provide substantial improvement in the film cooling performance, however, simultaneously producing undesirable cross flow ingestion into the film hole. Baheri et al's [8] numerical simulations for the same configuration showed that compound angle shaped holes with trench at the exit of circular and fanshaped film holes resulted a considerably higher average effectiveness. They observed that jet lift-off was eliminated at high blowing ratios for the trenched fanshaped hole, and the coolant spread more in the streamwise direction.…”