Abstract This study aims to investigate the impacts of thermal effect on cavitation, entropy features and interactions among vorticity, force coefficients and entropy production rate (EPR) in a liquid nitrogen cavitating flow. Numerical results demonstrate that the increase in free-stream temperature intensifies thermal effect and weakens cavitation intensity. The EPR by fluctuating velocity gradient ( S D ' ' ' ' ) dominates the evolution of EPR, and the cavity shedding or collapse increases the velocity gradient, thereby increasing S D ' ' ' ' . The variation trend of EPR by wall region ( S W ) is consistent with S D ' ' ' ' . By contrast, EPR by temperature gradient ( S C ' ' ' ' , S C ¯ ' ' ' ) always distributes on the liquid–vapour interface and increases with the development of the attached sheet cavity. Higher temperature acts as a disincentive to each item of EPR. The stable development of negative sheet vorticity at the leading edge increases the force coefficients nearly linearly. The counter clockwise vortex forms at the hydrofoil tail because the small-scale cloud cavity decreases the lift coefficient sharply. As the instability of attached sheet cavity is enhanced by re-entrant jet, the large vortex is dispersed into several clockwise vortexes, and positive vorticity occurs inside the cavity. Consequently, the force coefficients present a downward trend overall with intensive fluctuation. The distribution of EPR is similar to that of vorticity, and the opposite trend of entropy production integral and lift coefficient illustrates that the force can be used as a representation of energy loss to a certain extent.

中文翻译：

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瞬态液氮空化流动的数值研究，特别强调力演化和熵特征

摘要 本研究旨在研究热效应对液氮空化流中空化、熵特征以及涡度、力系数和熵产率（EPR）之间相互作用的影响。数值结果表明，自由流温度的增加会加剧热效应并减弱空化强度。EPR通过波动速度梯度（SD''''）主导EPR的演化，腔体脱落或坍塌增加了速度梯度，从而增加了SD''''。EPR随壁面区域（SW）变化趋势与SD'''''一致。相比之下，EPR 通过温度梯度 ( SC ' ' ' ' , SC¯ ' ' ' ) 总是分布在液-气界面上，并随着附着片腔的发展而增加。较高的温度对 EPR 的每一项都是不利的。前缘负片涡度的稳定发展几乎线性地增加了力系数。由于小尺度云腔使升力系数急剧下降，在水翼尾部形成逆时针涡旋。由于折返射流增强了附着片腔的不稳定性，大涡流被分散成几个顺时针方向的涡流，腔内出现正涡流。因此，力系数总体呈下降趋势，波动剧烈。EPR的分布类似于涡度的分布，