Abstract

Many experimental and numerical investigations of arrays of impingement cooling jets have been performed. A lot of them have addressed the problem of cooling with jets directed perpendicularly or inclined to the planar plate. However, in many technical applications contour of the cooled surface is more complex. One of the examples is a casing of the low-pressure turbine of the jet engine. It’s shape is determined by the turbine flow path and position of the blades and vanes located circumferentially inside the casing. Position of the cooling jets is limited by surrounding components, thermal expansion, and vibrations occurring during the engine operation. The investigation focused on the area at which the air has to be blown to achieve most effective cooling system for the complex geometry of the cooled surface is still open. The main goal of the numerical investigation performed in this study was to examine various axial positions of the jets directed perpendicularly to the non-planar shape of the surface to achieve the most effective Nusselt number distribution. Twenty-one analyses with different locations of array of cooling nozzles and various temperature ratios were taken into consideration. The numerical calculations of the thermal and flow parameters were performed using computational fluid dynamics code Ansys CFX.

摘要

已经对冲击冷却射流阵列进行了许多实验和数值研究。他们中的许多人已经解决了使用垂直或倾斜于平板的射流进行冷却的问题。然而，在许多技术应用中，冷却表面的轮廓更为复杂。其中一个例子是喷气发动机低压涡轮机的外壳。它的形状由涡轮流动路径以及沿圆周位于壳体内的叶片和叶片的位置决定。冷却喷嘴的位置受周围部件、热膨胀和发动机运行期间发生的振动的限制。调查的重点是必须吹空气以实现最有效冷却系统的区域，因为冷却表面的复杂几何形状仍然是开放的。本研究中进行的数值研究的主要目标是检查垂直于表面非平面形状的射流的各种轴向位置，以实现最有效的 Nusselt 数分布。考虑了冷却喷嘴阵列的不同位置和各种温度比的二十一种分析。使用计算流体动力学代码 Ansys CFX 进行热参数和流动参数的数值计算。考虑了冷却喷嘴阵列的不同位置和各种温度比的二十一种分析。使用计算流体动力学代码 Ansys CFX 进行热参数和流动参数的数值计算。考虑了冷却喷嘴阵列的不同位置和各种温度比的二十一种分析。使用计算流体动力学代码 Ansys CFX 进行热参数和流动参数的数值计算。