An experimental investigation on cooling characteristics of a vane laminated end-wall with axial-row layout of film-holes

摘要

A laminated cooling structure with axial-row layout of film-holes was employed in the design of a first-stage turbine vane end-wall. Different internal elements were placed in the regions near leading edge (LE), pressure side (PS) and suction side (SS). Conjugate heat transfer effects of fluid and solid at the laminated cooling end wall (LCE) were measured under low and engine-near temperature ratios (771s) of mainstream-to-coolant, respectively. The detailed comparison of overall cooling effectiveness and surface temperature gradients with a traditional film cooling end-wall (FCE) at three coolant-to-mainstream mass flow ratios (MFRS) and two TRs revealed that the LCE cannot only decease the temperature of the hot surface and the area of the regions difficult to be cooled by simple film cooling, but also decrease the temperature gradient within the end-wall, and improve the reliability and durability of the end-wall structure thereby. The overall cooling effectiveness of LCE can be increased by 15% in LE and SS regions and about 25% in PS region, when MFR is larger than 0.8%. The temperature gradients over the entire LCE can be reduced by about 20% at MFR = 1.2%. In addition, at the engine-near TR condition, these benefits of LCE mentioned above are still remarkable.