摘要
研究了复合台阶绕流中典型旋涡和壁面传热之间的关联性机理。通过PIV实验对所用的数值模拟方法进行了验证。从瞬态和时均两方面分析了早期过渡流区域复合台阶绕流的传热特性。结果表明:从层流到早期过渡流壁面的时均传热随雷诺数呈现出非线性的增长趋势,同时台阶底面局部区域的流动传热出现了非相似性。为了理清上述传热特征的形成原因,对一个振动周期里典型旋涡的形态特征和演变规律进行了分析,发现旋涡再附着冲击角γ,近壁冲击流速Ω和旋涡流向长度Lv是影响传热的三个关键因素。一般情况下,壁面传热随着γ和Ω的增大而增大。
The correlation between the typical vortex and heat transfer in the transitional flow is studied in a channel with a combined step. The numerical method used in this study is validated by PIV experiments. The heat transfer results in early transitional regime are obtained by investigating the instantaneous and time-average characteristics. The results show that the heat transfer has a nonlinear increase with the increase of Reynolds number and the dissimilarity appears in the local area of bottom wall.Moreover,the shape and motion of the typical vortices are analyzed in a periodic cycle of combined step flow. Based on the vortex evaluation,the correlation between the typical vortex and the heat transfer enhancement are studied. The results indicate that the vortex attack angle γ,the rotating speed Ω and the backflow region length Lv are three important factors on heat transfer. As a consequence,the vortex with the larger γ and Ω is more effective in wall heat transfer.
作者
瞿磊
谢纬安
喜冠南
张杰
QU Lei;XIE Wei-an;XI Guan-nan;ZHANG Jie(School of Automotive and Traffic Engineering,Nantong Vocational University,Jiangsu Nantong 226007,China;School of Mechanical Engineering,Nantong University,Jiangsu Nantong 226019,China)
出处
《机械设计与制造》
北大核心
2022年第5期10-14,19,共6页
Machinery Design & Manufacture
基金
江苏省高等学校自然科学面上项目(20KJB470013)
国家自然科学基金面上项目(51476080)。
关键词
强化传热
典型旋涡
旋涡演变
关联性
复合台阶
Heat Transfer Enhancement
Typical Vortex
Vortex Evaluation
Correlation
Combined Step Flow
