Ngwa Mboulé, Gao Longlong, Li Baoren
FESTO Pneumatic Technology Centre, School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
Entropy (Basel). 2022 Mar 24;24(4):451. doi: 10.3390/e24040451.
This paper uses heat transfer experiments and computational fluid dynamics (CFD) simulations to investigate the conjugate heat transfer (CHT) in a high-pressure pneumatic control valve assembly. A heat transfer test rig was constructed, and time-temperature histories of five test points placed on the valve assembly's outer surface were recorded for study validation. The Unsteady Reynolds-Averaged Navier-Stokes (URANS) CFD methods with the standard turbulence closure equations were adopted in the numerical computations. Polyhedral grids were used; time step and mesh convergence studies were conducted. Simulated and measured temperatures profile comparisons revealed a good agreement. The CHT results obtained from CFD showed huge velocity fields downstream of the valve throat and the vent hole. The airflow through the valve was icy, mainly in the supersonic flow areas. Low temperatures below 273.15 K were recorded on the internal and external walls of the valve assembly. The consistency of the measured data with the numerical results demonstrates the effectiveness of polyhedral grids in exploring the CHT using CFD methods. The local entropy production rate analysis revealed that irreversibility is mainly due to viscous dissipation. The current CHT investigation provides a potential basis for thermostress analysis and optimization.
本文采用传热实验和计算流体动力学（CFD）模拟方法，对高压气动控制阀组件中的共轭传热（CHT）进行了研究。搭建了一个传热试验台，并记录了放置在阀组件外表面的五个测试点的时间-温度历程，用于研究验证。数值计算采用了带有标准湍流封闭方程的非定常雷诺平均纳维-斯托克斯（URANS）CFD方法。使用了多面体网格；进行了时间步长和网格收敛性研究。模拟温度分布与测量温度分布的比较结果显示吻合良好。CFD获得的共轭传热结果表明，在阀喉和通风孔下游存在巨大的速度场。通过阀门的气流温度很低，主要出现在超音速流动区域。在阀组件的内壁和外壁上记录到了低于273.15K的低温。测量数据与数值结果的一致性证明了多面体网格在使用CFD方法探索共轭传热方面的有效性。局部熵产生率分析表明，不可逆性主要是由于粘性耗散。当前的共轭传热研究为热应力分析和优化提供了潜在依据。
