Flow and heat transfer in complex impingement cooling configurations for cooling applications in future gas turbine blades

本研究项目“用于未来燃气轮机叶片冷却的复杂冲击冷却结构中的流动与换热”(WO 872/9-1)最初提出已有4年。本提案专门用于第二阶段(第三和第四年)。该项目对具有壁面集成冷却射流的射流冲击冷却配置中的流动和换热特性进行了实验和数值研究，重点关注未来燃气轮机叶片的冷却概念。重点研究了几何约束和不同冷却射流排之间的相互作用对不同几何形状壁面上流体流动分布、混合行为和局部换热的影响。在前两年中，对具有不同流动和热条件的壁面整体冲击射流的复杂狭窄冲击情况下的速度和换热特性进行了详细的实验研究，并进行了数值模拟。采用暂态液晶(TLC)测量方法获得了局部换热分布。用粒子图像测速仪(PIV)进行了实验流动测量。由于这些研究的互补性，通过实验和数值模拟的相互作用，在时间平均流动和热状况的相互作用方面也取得了显着的结果。因此，特定的流动结构可以很好地与局部换热特性相关。然而，在调查过程中，出现了新的研究课题。这些问题涉及到在这种构型下操纵流动和换热的方法以及对数值模拟的要求。这些研究问题应该在第二项目阶段使用补充的测量方法来解决，更详细地量化流动接近条件，并在数值模拟中使用开源软件OpenFoam进行更详细的物理建模。此外，还将讨论探索热传递均质化可能性的方法。

The research project "Flow and heat transfer in complex impingement cooling configurations for cooling applications in future gas turbine blades" (WO 872/9-1) has been originally proposed for 4 years. The present proposal is dedicated towards the second phase (3rd and 4th year). The project addresses experimental and numerical investigations of flow and heat transfer characteristics in a jet impingement cooling configurations with wall integrated cooling jets focussing on future cooling concepts for gas turbine blades. The focus is on the influence of geometrical constraints and the interaction of different cooling jet rows on fluid flow distributions, mixing behavior and local heat transfer on the walls of such geometries.In the first 2 years, detailed velocity and heat transfer characteristics in a complex constricted impingement situation with wall integrated impingement jets for different flow and thermal conditions were experimentally investigated and corresponding numerical simulations were performed. Local heat transfer distributions were obtained using the transient liquid crystal (TLC) measurement method. Experimental flow measurements were made using Particle Image Velocimetry (PIV). Due to the complementary investgations significant results on the interaction between time-averaged flow and thermal situations have been gained experimentally as well from the interaction between experiments and numerical simulations. Therefrom specific flow structures could well be related to local heat transfer characteristics. However during the course oft he investigations new research topics arose. These relate to methods to manipulate flow and heat transfer in such configurations as well as demands on numerical modelling.These research questions should be addressed in the 2nd project phase using complementary measurement methods, quantifiying flow apprach conditions in more detail and using the open source software OpenFoam for more physically detailed modelling in the numerical simulations. Methods to explore possibilities for heat transfer homogenization will be addressed additionally.