基于LB方法的管内流动沸腾传热模拟

摘要

为研究竖直管内流动沸腾的传热情况及气泡行为学,采用格子玻尔兹曼(LB)方法,利用改进后的伪势模型和热模型分别模拟流动和传热过程.为验证模型的合理性,对模拟结果与经验关系式进行了定量对比.之后对气泡行为对沸腾传热系数的影响进行了研究,结果表明,随着气泡的核化、生长、滑移和脱离,传热系数呈现周期性波动.最后考察了重力加速度对气泡行为和沸腾传热的影响,重力越大,气泡生长周期越短,沸腾传热系数越大.%In order to study the heat transfer on flow boiling and bubble behavior in vertical tubes,the lattice Boltzmann (LB) method was used to simulate the flow and heat transfer processes respectively by the improved pseudo potential model and the thermal model.The simulation results were compared with the empirical relationships to verify the correctness of the model.The influence of bubble behavior on boiling heat transfer coefficient was investigated.The results show that the heat transfer coefficient presents periodic fluctuations with the nucleation,growth,slip and detachment of bubbles.Finally,the effect of gravity acceleration on bubble behavior and boiling heat transfer was investigated.The larger the gravity,the shorter the growth cycle of the bubble,the greater the boiling heat transfer coefficient.