Investigation of Effect Holes Twisted Angle and Compound Angle of Holes on Film Cooling Effectiveness

摘要

This paper investigates a new method of film cooling using swirling coolant flow through a rectangular twisted film cooling holes with spiral corrugated tube. Two different air flows with different temperatures were used in this study. Throughout the investigation, blowing ratio varied from 0.5 to 2.0 for several configurations of rectangular twisted angle of 0°, 90°, 180°, 270° and 360°. The results of cooling effectiveness obtained were compared against a standard untwisted tube. Results show that the overall thermal effectiveness improved significantly when the temperature difference between the air flows is at 25 degrees. Such improvement is supported by heat transfer enhancement that obtained from 19.7% to 57.4%. Based on these findings, the study concludes that using a specific geometry of film cooling holes with twisted configuration may result in an improve the convective heat transfer coefficient.