摘要
本文采用直接数值模拟方法结合拉格朗日点-粒模型研究了携带辐射热惯性颗粒的竖直槽道湍流两相流相间传热特性.研究中采用双向耦合模型描述分散相颗粒与流体之间的动量交换和热交换,辐射强度和颗粒Stokes数范围分别为1≤q/q0≤20,0.36×10^(−1)≤Stf≤2.16×10^(−1).研究发现辐射加热颗粒对流体的动力学调制加速了流体运动,使湍流强度增大.高辐射下的小Stokes数颗粒能显著加热流体.我们从流场时均温度方程出发,导出了两相流系统中相间传热Nusselt数的理论表达式,理论分析表明相间传热引起冷板和热板Nusselt数的差异,并进一步得到了相间传热效率与颗粒Stokes数及颗粒所受辐射强度的标度关系.
We investigated the interphase heat transfer characteristics in vertical turbulent channel flows laden with radiatively heated inertial particles considering the gravity of particles.Direct numerical simulation(DNS)combined with a Lagrangian point-particle strategy was carried out in the range of radiation intensity 1≤q/q0≤20 and the Stokes number of particles 0.36×10^(−1)≤Stf≤2.16×10^(−1)for particle diameter 33µm≤dp≤81µm.A two-way coupling model was adopted in which the momentum and heat exchange between the dispersed phase and the carrier phase were fully taken into account.It was found that when particles with small diameters encountered strong radiation significantly altered the heat transfer,so the fluid bulk temperature was remarkably heated.The theoretical expressions of the Nusselt number at the cold plate and the hot plate were derived from the time-average temperature equation of the fluid,which revealed that the interphase heat transfer caused the difference in heat transfer between the cold plate and the hot plate.We further found that interphase heat transfer increased linearly with the reciprocal of the particle diameter and the radiation intensity under the same mass fraction of particles.
作者
唐晓峰
潘明
杨文武
董宇红
Xiaofeng Tang;Ming Pan;Wenwu Yang;Yuhong Dong(Shanghai Institute of Applied Mathematics and Mechanics,School of Mechanics and Engineering Science,Shanghai University,Shanghai,200072,China;Shanghai Key Laboratory of Mechanics in Energy Engineering and Shanghai Institute of Aircraft Mechanics and Control,Shanghai,200072,China)
基金
the National Natural Science Foundation of China(Grant Nos.12172207 and 92052201).
