Detailed Film Effectiveness Distributions Research Articles

Thermal protection of rocket nozzle by using film cooling technology - effect of lateral curvature

The present paper aims to analyze the applicability of film cooling method to a rocket as a thermal protection. Lateral curvature effect on film cooling performance through a single row of cylindrical holes with different spanwise angles is investigated. Four different lateral curvature cases (C = ∞, 100, 60, 20) with four inclination angles of cooling injection holes (β= 35°, 45°, 55°, 65°) are considered. The ANSYS CFX has been used for this computational simulation. The turbulence is approximated by a shear stress transport model (SST). Detailed film effectiveness distributions are presented for several blowing ratios (0.5, 1 and 1.5). The numerical results are compared with experimental data.

Computation of leading edge film cooling from a CONSOLE geometry (CONverging Slot hOLE)

The aim of this study is to investigate the effect of mass flow rate on film cooling effectiveness and heat transfer over a gas turbine rotor blade with three staggered rows of shower-head holes which are inclined at 30° to the spanwise direction, and are normal to the streamwise direction on the blade. To improve film cooling effectiveness, the standard cylindrical holes, located on the leading edge region, are replaced with the converging slot holes (console). The ANSYS CFX has been used for this computational simulation. The turbulence is approximated by a k-e model. Detailed film effectiveness distributions are presented for different mass flow rate. The numerical results are compared with experimental data.

Effect of compound angle injection on flat surface film cooling with large streamwise injection angle

Film cooling measurements are presented over a flat surface through a single row of discrete holes angled 55° along the streamwise direction. The holes are angled 0° and 60° in the lateral direction to study the effect of compound angle injection. Detailed heat transfer coefficient enhancement and film effectiveness distributions are presented for the entire region from downstream of the holes to distances far downstream at about X/d=20. Tests were conducted in a low speed wind tunnel. The mainstream flow Reynolds number based on hole diameter is around 9500 and the free-stream turbulence intensity is set at 11%. Results are presented for three blowing ratios of 0.5, 1.0, and 1.5 and a coolant-to-mainstream density ratio of 1.0. A transient liquid crystal technique will be used to measure both the local heat transfer coefficient and film effectiveness results simultaneously. The technique uses two similar tests to resolve the heat transfer coefficient and film effectiveness. The detailed heat transfer coefficient and film effectiveness contours provide a clear understanding of the jet–mainstream interactions for different hole orientations with large streamwise angle injection. Results show that adding a compound angle to a hole with large streamwise angle produces significant variations in the detailed film effectiveness distributions and enhances local heat transfer coefficients.