Influence of groove structure on film cooling

Abstract

In the current work, the film cooling efficiency of flat plate film cooling and transverse groove film cooling is compared, and the impacts of various factors on the efficiency of film cooling are explored. The influencing factors include blowing ratio, incident angle and hole spacing. The results show that due to the existence of CRVP, the cooling jet will be entrained and separated from the wall, resulting in low film cooling efficiency. For film cooling with transverse grooves, the existence of transverse grooves will inhibit the generation of CRVP and make it more close to the wall flow. Therefore, the efficiency of film cooling is high. In addition, the gas film formed by the transverse groove is more evenly distributed in the spanwise direction. In the flow field, the film cooling efficiency at 1 < X/D < 4 is further increased when BR = 1.0, 1.5 and 2.0. The film cooling efficiency of flat plate is less sensitive to the incident angle. When there is no CRVP, the film cooling efficiency increases as incident angle increases. In contrast, when CRVP is produced, the efficiency of film cooling reduces as incident angle increases. With increasing hole spacing, the strength of CRVP generated from plate film cooling raises, leading to the reducing efficiency of film cooling.

Keywords

• Film cooling
• Transverse groove
• Blowing ratio
• Incident angle
• Hole spacing