燃气轮机一级透平动静叶交互作用的气膜非定常特性及泛冷却效应:Part2-动叶栅

Unsteady Characteristic of Film Cooling and Phantom Cooling on the First Stage of a Gas Turbine:Part 2-Blade Cascade

采用三维非定常数值模拟计算某重型燃气轮机第一级透平的全气膜冷却特性,探讨级环境下静叶表面与静叶端壁及动叶表面与动叶平台的气膜非定常特性及泛冷却效应.燃气轮机泛冷却是指燃气轮机透平冷却气体出流在非设计位置所引起的附加效果.该部分工作包含两部分内容,第二部分关注级环境下动叶表面与动叶平台的气膜冷却特性,以及动静叶间隙轮缘密封出流在下游动叶栅中所形成的泛冷却效应.结果表明,在上游尾迹影响下,动叶中截面压力及动叶表面与平台的气膜冷却效率分布呈现较强的非定常性;动静叶间隙轮缘密封出流在平台上形成气膜覆盖,同时在动叶吸力面近尾缘叶根区域形成泛冷却效应,且形成泛冷却效应的范围相比静叶更大;此外,静叶全气膜能够进一步强化该区域的泛冷却效应.

3-D URANS （unsteady Reynolds average N-S equations simulation） is implemented to investigate the film cooling performance on the first stage of a gas turbine, discussing the unsteady characteristics of film cooling and phantom cooling in the stage environment. The phantom cooling is defined as the adjunct effect on the off-design position derived from the upstream cooling discharges. The present work includes two parts of content. The part 2 focuses on the unsteady film cooling characteristic of the blade and platform on the first stage, and the phantom cooling derived from the ejection of the rim seal between vane and blade. The results of pressure on the middle crossing plane of the blade and film cooling effectiveness on the blade surface and platform are significantly unsteady due to the strong wake of the vane trailing edge. The rim seal ejection produces film cooling coverage on the platform, and simultaneously generates phantom cooling effect on the zone of suction side near trailing edge and blade root. Furthermore, the zone phantom cooling influencing on is wider than that in vane cascade. Moreover, the phantom cooling effect is consolidated with the vane full film cooling.