Experimental investigation on film cooling characteristics from a row of holes with ridge-shaped tabs

• Published in: Experimental thermal and fluid science 2012-02, Vol.37, p.113-120
• Main Authors: Yang, Cheng-feng, Zhang, Jing-zhou
• Format: Article
• Language: English
• Subjects: Applied sciences; Blowing; Cooling; Cooling effectiveness; Covering; Discharge coefficient; Energy; Energy. Thermal use of fuels; Engines and turbines; Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc; Exact sciences and technology; Film cooling; Fluid dynamics; Fluid flow; Heat transfer coefficient; Pressure drop; Ridge-shaped tab; Tabs
• ISSN: 0894-1777; 1879-2286
• DOI: 10.1016/j.expthermflusci.2011.10.011

► Ridge-shaped tabs were present on injection holes to enhance film cooling effectiveness. ► We explore mechanism of ridge-shaped tabs on enhancement in cooling effectiveness. ► We examine the effect of ridge-shaped tab covering ratios on the film-cooling performance. ► Ridge-shaped tabs are capable of suppressing the coolant jet penetration into primary flow. Experimental study was conducted to investigate the enhanced cooling performance caused by ridge-shaped tabs located along the upstream edge of the film cooling holes. Three covering ratios of ridge-shaped tab on film hole and four blowing ratios were considered in the present. The results show that the presence of ridge-shaped tabs in the nearby region of the primary film cooling holes mitigates the primary vortices due to mainstream–coolant jet interaction in the downstream region. The lower penetration of coolant jet provides an increment in the film cooling effectiveness and also enhance heat transfer coefficient over the baseline case. The ridge-shaped tabs provide enhancements in cooling effectiveness, but this is at the expense of larger pressure drop, especially for ridge-shaped tabs with bigger covering ratio.