Experimental investigation of full-coverage film cooling characteristic of single/double-wall cooling vane

This paper employed the pressure sensitive paint (PSP) technique to measure the adiabatic film cooling effectiveness distributions of both the single-wall cooling vane (SCV) and the double-wall cooling vane (DCV). The experiments were implemented in an annual cascade under a Reynolds number of 3.0 x 105 condition. Furthermore, the effects of mass flow ratio (MFRs include 4.99 %, 6.65 %, 8.32 %, 9.98 %, and 11.65 %) and density ratio (DRs include 1.0, 1.5, and 2.0) on the adiabatic effectiveness distribution were also investigated. The results reveal that the DCV improves dramatically the film cooling effectiveness of the pressure side and the suction side compared with the SCV, and the effectiveness is elevated by 12 % and 25 %, respectively. As the MFR increases, the lateral average film cooling effectiveness of the SCV initially increases and then decreases, while that of the DCV enhances monotonously. Additionally, when the DR is raised from 1.0 to 1.5, the lateral average film cooling effectiveness of the pressure side of the SCV is increased by 50 % at the MFR = 6.65 %. Also, the DCV presents both high and even film cooling effectiveness contour distribution at high density ratio conditions, and the surface average film cooling effectiveness of the DCV is greater than 0.4 when the MFR >= 8.32 %.