【作者】 李江海；

【导师】 朱惠人；

【作者基本信息】 西北工业大学 ， 工程热物理， 2005， 硕士

【摘要】 多孔层板冷却技术是一种新型冷却技术,集冲击、对流和气膜冷却于一体,具有冷气消耗量小,冷却效率高的特点,在国外的应用越来越广泛。本文通过实验和数值模拟研究了层板的流动特性和冷却特性。 设计制造了6块单层平板以及6块单层叶片。分别在大尺寸低速回流式风洞和热风洞中进行了流阻特性和冷却特性实验。 流阻特性实验表明:层板的流阻主要取决于开孔率,开孔率越大,流阻越小。其余几何参数如通道高度等对流阻也有一定影响。 冷却特性实验表明:层板具有很高的冷却效率;层板冷却效率主要取决于开孔率;层板叶片压力面的冷效略高于吸力面。 用FLUENT 6.1对4块层板平板进行了实验工况下的数值模拟,结果表明计算结果在总体趋势上和实验一致。流阻计算结果和实验符合得较好,部分冷效计算结果与实验有一定差距。 对16种不同几何结构尺寸的层板进行了系统的三维耦合数值计算,研究了通道高度等几何参数对层板流阻和冷效的影响。结果表明,在相同的冷气密流条件下,减小通道高度、增大孔的疏密度可显著提高冷却效果,但同时也使流动阻力增大。孔距对冷却效果影响不大,但对流阻有重大影响。层板强化换热主要集中在内部表面,冷气侧的换热对冷效的影响不大。本文的结果可为层板的优化设计提供参考。更多还原

【Abstract】 Lamilloy is a new cooling technology which has advantage of combining film cooling, internal impingement, large internal heat transfer area and enhanced heat exchange by pin fin array and has characteristic of small quantity coolant consumption and high cooling effectiveness.It has been used on board.The resistance and cooling characteristic of lamilloy were investigated with experimental and numerical simulation in this paper.In this paper,six single layer laminate plates and blades were made.The resistance and cooling characteristic were investigated in a large scale low speed close-looped wind tunnel and heat wind tunnel respectively.The experimental results of resistance investigation indicated that the resistances of laminate plate and blade were mainly determined by the ratio of the hole area to the plate, and the bigger the ratio, the smaller the resistance. The other geometries such as height of the channel were secondary importance.The experimental results of cooling effectiveness investigation indicated that very high effectiveness can be achieved by using lamilloy and the ratio of the hole area to the plate will play the most important role of cooling effectiveness. The cooling effectiveness of pressure side of blade was higher than suction side.Numerical simulation were conducted to calculate four laminate plates with three types of flow patterns under experimental conditions.The resistance and cool -ing effectiveness were obtained.The simulation results were in good agreement with the experimental data but large discrepancies exited in some cases.Conjugate three dimension coupled fluid/solid numerical simulation was carried out for sixteen Lamilloy configurations with different geometry parameters. Numerical results showed that in the condition of same coolant mass flux cooling effectiveness can be increased by reducing passage height and hole diameter of Lamilloy, but the resistance of it became larger simultaneity. Large size of the internal heat transfer surfaces and high value of heat transfer coefficient created by the coolant impingement lead to a large portion of the heat to be removed. The obtained results would be valuable for the optimization in designing Lamilloy.更多还原