Development of renewable energy technology and improvement of energy efficiency have currently become necessary. In particular, active ultrasonic cavitation has attracted a great deal of attention in the enhancement of heat transfer efficiency, and this has been investigated in the current work using numerical methods. A physical model and associated simulation methods are first introduced. Next, the influence of various operational parameters on heat transfer enhancement are presented and analyzed. Finally, simulations with different configurations, with the inclusion of ultrasonic vibrations, are presented. The results show that the average outlet temperature and Chilton and Colburn factor j rise with increasing ultrasonic amplitudes and Reynolds numbers, but decrease with increasing ultrasonic frequencies. The friction factor f decreases with similar changes in parameters. The optimum values obtained for Reynolds number and ultrasonic frequency are 63.5 and 20 kHz, respectively. Additionally, the ultrasonic vibrations enhanced the heat transfer performance at the front and back pipe walls. It is recommended that ultrasonic vibrations be applied at pipe locations with fully developed flow.

中文翻译：

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交错管道中传热的超声增强

目前，发展可再生能源技术和提高能源效率已经成为必要。特别地，主动超声空化在提高传热效率方面引起了极大的关注，并且这在当前的工作中已经使用数值方法进行了研究。首先介绍了物理模型和相关的仿真方法。接下来，介绍并分析了各种运行参数对传热增强的影响。最后，介绍了具有不同配置的模拟，其中包括超声振动。结果表明，平均出口温度和Chilton和Colburn因子j随超声振幅和雷诺数的增加而增加，但随超声频率的增加而降低。摩擦因数f随着参数的类似变化而减小。雷诺数和超声频率的最佳值分别为63.5和20 kHz。此外，超声振动增强了前管壁和后管壁的传热性能。建议在流量充分发展的管道位置施加超声振动。