Heat Transfer in Cooling Channels Near Trailing Edges of GasTurbine Blades

为了实现电厂的高效率，电厂中的涡轮机必须在尽可能高的温度下运行。目前的材料对这些温度设置了限制，因此有必要对涡轮机叶片进行冷却，以在通过涡轮机的高温气体面前保持其完整性。一种方法是让冷却剂通过位于叶片内的流动通道。为了进一步加强通道内的换热，使用了翅片或肋片。现有的关于这种翅片或肋片通道的换热特性的信息不足以进行设计。根据本建议进行的实验将弥补这一不足。热传递测量将由通过萘升华技术进行的传质测量来补充。通过两个过程之间的类比，将测得的传质系数转换为换热系数。所获得的数据不仅将用于设计，还将用于验证数值模拟。

To achieve high power plant efficiencies, the turbines in the plant must operate at the highest possible temperature. Present-day materials place a limit on these temperatures, so that cooling of the turbine blades is necessary to maintain their integrity in the face of the high temperature gases that pass through the turbine. One approach is to pass a coolant through flow passages situated within the blades. To further enhance the heat transfer within the passages, fins or ribs are used. The available information about the heat transfer characteristics of such finned or ribbed passages is insufficient for design. The experiments to be performed under the present proposal will remedy this deficiency. The heat transfer measurements will be supplemented by mass transfer measurements carried out by means of the naphthalene sublimation technique. The measured mass transfer coefficients will be converted to heat transfer coefficients via the analogy between the two processes. The obtained data will not only be useful for design but will also serve to verify numerical simulations.