凹陷涡发生器结构和尺寸对流动和传热影响的数值计算研究

发布时间：2018-06-22 00:11

本文选题：燃机冷却 + 凹陷　；参考：《上海交通大学》2015年硕士论文

【摘要】：提高燃气轮机出功的一重要途径是提高燃气温度,而燃气温度的提高对叶片等受热材料的热性能有更好的要求,因此发展更有效的冷却结构已经成为燃气轮机研发技术的瓶颈之一。而凹陷结构的突出优点是在提高传热效果的同时又可以避免过大的压力损失,因此在将来燃气轮机内部冷却中具有很好的应用前景。本文的主要工作是通过数值计算对凹陷内的流动和传热进行准确模拟并与实验相验证,根据计算结果对不同凹陷的流动和传热情况进行了深入分析比较。具体如下:利用稳态模型数值计算模拟研究了球形,椭球型,倾斜椭球型和泪滴型四种不同形状凹陷的流动和传热性能;比较了带肋球形凹陷和不带肋球形凹陷的传热和流动效果并研究了肋高度对流动和传热的影响;比较了前倒圆和全倒圆与对应球形凹陷的流动和传热区别;探究了凹陷深度对流动和传热的影响。研究结果表明:在雷诺数分别为8500,18700,36700,50500,60000下,四种不同形状凹陷中泪滴型凹陷的换热效果最好,虽然其摩擦阻力也最大,而且泪滴型凹陷的综合热性能也最好;1.0mm的带肋凹陷换热比球形凹陷高出30%-40%,摩擦因子比球形凹陷高出80%左右;肋高对凹陷的流动和传热有一定影响,随着肋高的增加凹陷传热有所增强,但摩擦阻力也显著增大;前倒圆的换热情况比球形凹陷略高3%左右,传热分布比球形凹陷均匀且摩擦阻力明显更小。全倒圆换热比球略低2%左右,但摩擦阻力最小,综合热性能最好。深度对凹陷传热影响,随着深度增加球形凹陷换热越强,摩擦阻力损失越大,从综合热性能参数来看凹陷深度为2mm的球形凹陷综合热性能最好。
[Abstract]:An important way to increase the output power of gas turbine is to raise the gas temperature, and the increase of gas temperature has better requirements for the thermal performance of heated materials such as blades. Therefore, the development of more effective cooling structure has become one of the bottlenecks of gas turbine research and development technology. The outstanding advantage of the concave structure is that it can not only improve the heat transfer effect but also avoid excessive pressure loss, so it has a good application prospect in the future gas turbine internal cooling. The main work of this paper is to simulate accurately the flow and heat transfer in the sag by numerical calculation and to verify the experimental results. The flow and heat transfer in different sag are analyzed and compared according to the calculation results. The main contents are as follows: the flow and heat transfer characteristics of four kinds of hollow with different shape are studied by numerical simulation of steady state model, such as spherical, ellipsoid, inclined ellipsoid and tear droplet. The effects of heat transfer and flow in the spherical sag with and without ribs are compared, and the influence of rib height on the flow and heat transfer is studied, and the difference between the flow and heat transfer in the front inverted circle and the full inverted circle is compared with that in the corresponding spherical depression. The effect of indentation depth on flow and heat transfer was investigated. The results show that the heat transfer efficiency of the tear drop type sag is the best in the four different shapes of the sag, even though the friction resistance is the largest, at the Reynolds number of 18700 ~ 36700 ~ 50500 ~ (60 000), respectively. Moreover, the comprehensive thermal properties of tear-drop type sag are better than that of spherical sag, the heat transfer of 1.0 mm ribbed sag is 30-40% higher than that of spherical sag, the friction factor is about 80% higher than that of spherical sag, and the rib height has certain influence on the flow and heat transfer of the sag. With the increase of rib height, the heat transfer of the depression increases, but the friction resistance also increases significantly, the heat transfer of the front inverted circle is slightly higher about 3% than that of the spherical sag, and the heat transfer distribution is more uniform than that of the spherical sag and the friction resistance is obviously smaller than that of the spherical depression. The total reverse circle heat transfer is about 2% lower than that of the ball, but the friction resistance is the least, and the comprehensive thermal performance is the best. The effect of depth on the heat transfer of the sag, the stronger the heat transfer of the spherical sag with the increase of the depth, the greater the friction resistance loss, and the better the comprehensive thermal performance of the spherical sag with the depth of 2mm from the point of view of the comprehensive thermal performance parameters.
【学位授予单位】：上海交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TK471

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