Zhang Zhe, Luo Xiang, Peng Yubo
School of Energy and Power Engineering, Beihang University, Beijing 100191, China.
Research Institute of Aero-Engine, Beihang University, Beijing 100191, China.
Micromachines (Basel). 2024 Mar 28;15(4):452. doi: 10.3390/mi15040452.
Transpiration cooling based on a porous structure has an ultra-high cooling efficiency, which is expected to be one solution to improve the cooling technology of aero-engine turbine blades. However, particulate impurities in the gas flow channel continue to deposit on the surface of turbine components, blocking cooling holes, which causes great harm to the cooling of turbine blades. In this study, a sintered metal mesh plate was selected as the transpiration cooling structure, and the evolution of particle deposition quality and deposition thickness on the transpiration cooling surface with time, as well as spatial distributions of particle deposition thickness at different times, were explored through experimental and simulation methods. The results showed that, with the increase in spray time, deposition quality and maximum deposition thickness of the transpiration cooling surface gradually increased. Along the main-stream direction, when spray time was short, deposition thickness was higher in a narrow range upstream of the experimental specimen. With the increase in spray time, deposition thickness gradually decreased along the direction of the transpiration cooling mainstream. In the spanwise direction, when spray time was very short, deposition thickness in the spanwise direction was more consistent and, after spray time increased further, the deposition thickness distribution began to tend to a "∩"-type distribution. It can be seen from the simulation results of the metal wire mesh particle deposition that particles were easily deposited on the windward side of the metal wire in the main-stream direction, which agreed with the experimental distribution characteristics of the metal wire mesh deposition. Moreover, the increase in blowing ratio reduced the deposition of particles on the wall of the metal wire mesh.
基于多孔结构的发汗冷却具有超高的冷却效率，有望成为改进航空发动机涡轮叶片冷却技术的一种解决方案。然而，气流通道中的颗粒杂质不断沉积在涡轮部件表面，堵塞冷却孔，这对涡轮叶片的冷却造成极大危害。在本研究中，选择烧结金属网板作为发汗冷却结构，通过实验和模拟方法，探究了发汗冷却表面颗粒沉积质量和沉积厚度随时间的演变，以及不同时刻颗粒沉积厚度的空间分布。结果表明，随着喷雾时间的增加，发汗冷却表面的沉积质量和最大沉积厚度逐渐增大。沿主流方向，喷雾时间较短时，在试验件上游较窄范围内沉积厚度较高。随着喷雾时间的增加，沉积厚度沿发汗冷却主流方向逐渐减小。在展向方向上，喷雾时间非常短时，展向沉积厚度较为一致，喷雾时间进一步增加后，沉积厚度分布开始趋于“∩”型分布。从金属丝网颗粒沉积的模拟结果可以看出，颗粒在主流方向上容易沉积在金属丝的迎风侧，这与金属丝网沉积的实验分布特征相符。此外，吹风比的增加减少了颗粒在金属丝网壁上的沉积。
