【作者】 杨炳昌；

【导师】 金东旭；

【作者基本信息】 大连理工大学 ， 制冷及低温工程， 2012， 硕士

【摘要】 随着科学技术的不断发展,能源环境等问题也不断的出现,如何更好的利用能源,提高能源的利用率得到了越来越多人的重视。强化传热技术作为提高换热效率的主要方式在能源节约中起着非常重要的作用,已经成为各国学者研究的一个方向。脉动流动技术作为强化换热技术的一个主要方式已经被人们用数值和实验方法证实。本文采用实验的方法对三角槽通道内层流脉动流动强化换热进行研究,分析了不同雷诺数Re,斯德鲁哈尔数St,脉动振幅A以及三角槽通道的槽深(6mm,9mm和12mm)对强化换热的影响。结果表明脉动扰动显著地提高了三角槽通道的传热能力。稳态时,努赛尔数随着雷诺数的增大而增大,努赛尔数随着三角槽深度的增加先增大后减小；脉动时,传热强化因子随着雷诺数和脉动振幅的增加而增加。而当雷诺数和脉动振幅一定时,强化传热因子随着斯特鲁哈尔数的增大先增加后减小,存在一个使强化传热因子达到最大的最佳斯特鲁哈尔数,并且对于不同的雷诺数和脉动振幅使强化传热因子达到最大的脉动频率是相同的。当三角槽的槽深为12mm时,强化传热因子最大,而当槽深为9mm时,强化传热因子最小。三角槽的槽深对最佳斯特鲁哈尔数没有影响。压力梯度的脉动振幅随着雷诺数,脉动振幅的增大而增大,随着脉动频率的增大而减小更多还原

【Abstract】 With the continuous development of science and technology, many problems have been emerged, especially in energy and environment. How to make better use of energy and improve the energy utilization have attracted more and more attention. Heat transfer enhancement as a major method of improving heat efficiency plays an important role in energy saving, which has been investigated by the researches all over the world. Pulsating flow as a main way of heat transfer enhancement has numerically and experimentally confirmed.Heat transfer enhancement by laminar pulsating flow in triangular grooved channels was experimentally investigated by taking various factors into consideration, such as, Reynolds number, Strouhal number, pulsation amplitude and groove depth (6mm,9mm and12mm).The results show that pulsating flow agitation promotes the heat transfer in triangular grooved channels. In steady flow case, Nusselt number increases as the Reynolds number increases, and it increases at first and then decrease with the increase of groove depth. In pulsating flow case, the heat transfer enhancement factor is improved with the increase of Reynolds number and pulsation amplitude. And the heat transfer enhancement factor increases firstly and then decreases with the increase of Strouhal number. There exists an optimal Strouhal number corresponding to the maximum heat transfer enhancement factor. The Reynolds number and pulsation amplitude have no effect on the optimal pulsation frequency. The heat transfer enhancement factor gets the maximum value when the groove channel depth is12mm and reaches the minimum value when the depth is9mm. And the groove channel depth has no influence on the optimum Strouhal number. The amplitude of pressure gradient increases with the increase of Reynolds number and pulsation amplitude, and decreases with the increase of pulsation frequency.更多还原