应用红外技术进行层板冷却特性的研究

在大尺寸低速风洞中采用红外热成像仪对3种应用于涡轮叶片的典型多孔层板结构进行了冷却有效性的实验研究，通过开发的红外热像仪程序包获得了层板表面详细的壁温分布和冷效分布，运用参数分析了层板结构参数对其冷却有效性的影响。结果表明多孔层板结构具有很高的冷却有效性，开孔率是影响冷却有效性的决定因数，开孔率越大，冷效越高。参数f、燃气侧气膜冷却效率ηf和层板内部换热效率ηi是层板优化设计的重要依据。红外测温技术以其非接触和快捷有效的优势在多孔层板冷却特性的研究中具有重要的应用价值。

On Improving Cooling Effectiveness of Lamilloy with Infrared Technique

Lamilloy research attracts increasingly the attention of aeronautical powerplant engineers, both in China and abroad. Since 1998,we have engaged in research on Lamilloy to improve its cooling effectiveness. This research requires painstaking planning and execution of experimental investigation and careful analysis of experimental results. We made and tested three typical configurations of Lamilloy in a large-scale low-speed close-looped wind tunnel by infrared thermography. We obtained detailed two dimensional contour maps of temperature and cooling effectiveness. The experimental results showed that very high cooling effectiveness can be achieved with Lamilloy .The hole area ratio of Lamilloy plays the most important role in determining cooling effectiveness; the bigger the ratio, the higher is the cooling effectiveness. We derived a non-dimensional parameter f for analyzing cooling effectiveness. We find that in optimizing the design of Lamilloy, three parameters are important: parameter f, the adiabatic effectiveness of film cooling at gas side, and the internal heat transfer efficiency of Lamilloy configuration. In this paper, we discuss in much detail how these three parameters should be dealt with in optimizing Lamilloy design. Although infrared technique began to be employed in heat transfer research only a few years ago, we believe that it has a promising future for assessing the relative cooling effectivenesses of different configurations of Lamilloy.