The present study explores the effect of damping ratio and Reynolds number on the flow-induced vibration and heat transfer behavior of a heated square-section cylinder. To this end, fluid-structure interaction simulations based on the finite-volume method are conducted for five different damping ratios of = 0, 0.01, 0.05, 0.1, 0.25 and 0.5 at four representative Reynolds numbers of = 80, 90, 220 and 250. By considering the square-section cylinder as a mass-spring-damper system, one can model its free vibration along transverse and streamwise directions due to lift and drag forces exerted from the fluid, in which the dynamic mesh technique is employed to couple the cylinder motion with the flow field. Owing to its sharp corners, the square-section cylinder first experiences the lock-in condition in which the vortex shedding frequency approaches the oscillator natural frequency. After surpassing the critical flow velocity, the square-section cylinder undergoes high-magnitude and low-frequency oscillations known as galloping. For a more comprehensive evaluation, the designated Reynolds numbers encompass all vibration regions of the square-section cylinder: out of lock-in and galloping ( = 80), middle-point of lock-in region ( = 90), middle-point of galloping ( = 220) and the peak of galloping zone ( = 250). The results show that at = 90, as the damping ratio increases from = 0.01 to = 0.05, the amplitude of cylinder oscillations significantly drops due to the de-synchronization type action. A notable reduction in the oscillation amplitude at = 220 and 250 occurs with increasing damping ratio from = 0.1 to = 0.25, attributed to the hidden frequency emersion phenomenon in which the fundamental frequency of cylinder transverse oscillations shifts to a secondary value. It is also shown that the heat transfer rate of the square cylinder with free vibration is more than that of a stationary cylinder. With increasing damping ratio, the heat transfer rate of the cylinder decreases compared to the undamped conditions.

中文翻译：

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不同阻尼比受热方截面圆柱传热特性及二维FIV综合研究


本研究探讨了阻尼比和雷诺数对加热方形截面圆柱体的流致振动和传热行为的影响。为此，在四个代表性雷诺数 = 80、90、220 和 250 下，对五个不同阻尼比 = 0、0.01、0.05、0.1、0.25 和 0.5 进行基于有限体积法的流固耦合模拟通过将方形截面圆柱体视为质量-弹簧-阻尼器系统，可以对其由于流体施加的升力和阻力而沿横向和流向方向的自由振动进行建模，其中采用动态网格技术来耦合。气缸随流场运动。由于其尖角，方形截面圆柱体首先经历锁定状态，其中涡旋脱落频率接近振荡器固有频率。超过临界流速后，方形截面圆柱体会经历高强度和低频振荡，称为舞动。为了进行更全面的评估，指定的雷诺数涵盖了方形截面气缸的所有振动区域：失锁和舞动（= 80）、锁定区域中点（= 90）、奔腾 (= 220) 和奔腾区峰值 (= 250)。结果表明，在 = 90 时，随着阻尼比从 = 0.01 增加到 = 0.05，由于去同步型作用，气缸振动的幅度显着下降。随着阻尼比从 = 0.1 增加到 = 0.25，= 220 和 250 处的振荡幅度显着减小，这归因于隐藏频率再现现象，其中圆柱横向振荡的基频转移到次要值。 还表明，自由振动的方圆柱体的传热速率高于静止圆柱体的传热速率。随着阻尼比的增加，气缸的传热速率与无阻尼条件相比降低。