飞机后设备舱自然对流换热的实验与模拟

Experiment and Numerical Simulation on Natural Convection Heat Transfer in Aircraft Equipment Bay

飞机后设备舱内换热是涉及自然对流与辐射换热耦合的复杂问题,选择合适的计算模型,利用CFD数值模拟进行计算分析是解决此类问题的简便方法.针对这一问题,搭建了一个可控热边界的实验台,通过实验测量了壁面温度等作为CFD数值模拟的边界条件,采用RNG k-ε湍流模型和DO辐射模型进行计算预测.通过对比实验结果与CFD模拟计算结果,发现RNG k-ε湍流模型能较好地预测封闭空间自然对流温度场和流场,自然对流换热和辐射换热分别占总换热量的89%,和11%,.

Heat transfer process in aircraft equipment bay is a combination of natural convection and radiation. Tosolve such a complicated problem,it is popular to use computational fluid dynamics(CFD)based on appropriate andvalidated turbulence and radiation computational models. Therefore,an experiment platform with controllableboundary was set up. The boundary conditions of CFD simulation,such as the wall temperature,were obtainedthrough experiment. Renormalization group k-ε (RNG k-ε)turbulence model and discrete ordinates(DO) radiationmodel were used in CFD simulation. By comparing the results of the CFD simulation and experiment,it is found thatthe numerical simulation based on the RNG k-ε turbulence model can predict the distribution of temperature and airflowof natural convection in enclosed space. The percentage of natural convective heat transfer rate is 89%,,while itis 11%, for radiant heat transfer rate.