摘要
通过采用瞬态液晶热像测试技术,对具有Ⅴ肋-凹陷涡发生器复合结构的表面湍流流动和传热特征进行了实验研究,分析了雷诺数(Re)在10 000~60 000内具有不同肋高的Ⅴ肋-凹陷阵列表面高精度传热分布,以及流阻损失特征.实验结果表明:充分发展湍流条件下的Ⅴ肋-凹陷结构表面传热性能是光滑通道传热性能的1.98~2.46倍,摩擦因子是后者的2.24~4.36倍;Ⅴ肋-凹陷表面传热性能是球形凹陷表面传热性能的1.21~1.76倍,摩擦因子是球形凹陷的1.96~3.89倍.在Re<20 000的条件下,具有0.6和1.0mm高的Ⅴ肋复合结构表面的综合热性能比具有1.5mm高的Ⅴ肋-凹陷表面高约4.7%~12.8%;随着Re继续提高,0.6和1.0mm Ⅴ肋-凹陷的综合换热能力逐渐降低,而1.5mm Ⅴ肋-凹陷的综合换热能力逐渐上升,且比0.6和1.00mm Ⅴ肋-凹陷高约4.7%~8.3%.
A structured surface with small-sized V ribs and dimples is a potentially high-performance cool- ing structure used for gas turbine blades. A comparative transient liquid crystal （TLC） transient experi- mental study was conducted to obtain the high-resolution heat transfer characteristics and pressure loss in the cooling channels with different heights of V-shaped rib-dimple in the Reynolds number range of 10 000 to 60 000. The results indicated that, under the condition of fully developed turbulent flow, the Nusselt number of the V-shaped rib-dimple is 1.98 to 2.46 times of that of the smooth flat, with a friction factor of 2.24 to 4.36 times of that of the smooth flat. The Nnsselt number of the V-shaped rib-dimple is 1.21 to 1.76 times of that of circular dimples, with a friction factor of 1.96 to 3.89 times of that of circular dim- pies. Both the depth and Reynolds number of V-shaped rib can influence the flow field structure. The overall thermal performance factor of the V-shaped rib-dimple with a depth of 0. 6 and 1.0 mm is 4.7% to12.8o//oo higher than with a depth of 1.5 mm at a low Reynolds number （Re%20 000）. With a continuous increase of the Reynolds number, the overall thermal performance of V-shaped rib-dimple with a depth of 0.6 and 1.0 mm depth gradually decreases, but the overall thermal performance of V-shaped rib-dimple with a depth of 1.5 mm gradually increases, and is 4.7% to 8.3% higher than that with the depths of 0.6 and 1.0 mm.
出处
《上海交通大学学报》
EI
CAS
CSCD
北大核心
2017年第1期40-45,共6页
Journal of Shanghai Jiaotong University
基金
国家自然科学基金(51676119
51176111)
上海交通大学燃气轮机研究院资助项目
关键词
V形肋
凹陷涡发生器
瞬态液晶热像
对流冷却
燃气轮机
V rib
dimple
transient liquid crystal thermography （TLCT）
convective cooling
gas turbine
