振动对管内流体对流传热影响实验研究

Experiment study of vibration effect on convective heat transfer characteristics of internal flow in tube

利用实验的方法研究了水平圆管在高频低振幅的横向振动条件下,管内流体的传热特性,分析了不同振动参数对管内流体传热的影响.针对振动对传热影响的研究使用实验测量的振动加速度进行频谱分析得出共振频率.结果表明:随着振动频率的增加管内对流换热系数先增大,达到峰值(共振频率下)后迅速减小,最终趋于稳定;随着振动加速度的增大,管内对流换热系数增大,且振动频率对传热的影响要强于振动加速度.传热强度最高提升14.94%.此外,根据实验结果拟合了Nu增强率关联式,将拟合结果与实验值进行比较,误差最大在8.02%左右,可为工程实际应用提供参考.

The experiments are carried out to investigate the effects of horizontal vibrations with high frequency and low amplitude on heat transfer characteristics of internal flow in horizontal circular tube.The influence of different vibration parameters on heat transfer of internal fluid is analyzed.The value of vibration acceleration which is measured by the experiment is used to make frequency spectrum analysis,and the resonance frequency is obtained.The result shows that the internal convective heat transfer coefficient increases with the raise of vibration frequency.When it reaches the peak value(in the resonance frequency),it will decrease quickly and tend to be stable finally;the internal convective heat transfer coefficient also increases with the raise of vibration acceleration,and the vibration frequency has more influence than the vibration acceleration.The heat transfer coefficient is highest increased by 14.94%.In addition,a correlation for Nuenhanced ratio is deduced according to the experimental results.After comparing the values between fitting result and experimental result,it is found that the maximum error is about 8.02%,and it can provide a reference for engineering application.