基于不同对流下加热系统的数值模拟与实验研究

采用多孔介质导热方程、DO辐射模型以及标准κ-ε湍流模型,建立三维热物理模型。应用有限体积法计算了室内沙疗室气固耦合传热问题。首先在自然对流条件下,即沙疗室不开风扇、处于无风状态时,改变其加热方式,分别为单面加热和双面加热。对比分析不同加热方式下,空气层以及沙体层温度场的变化。其次在双面加热条件下,改变其对流方式,分别为自然对流与强制对流。对比分析不同对流方式下,空气层温度场、速度场的变化,以及沙体层温度场的变化。最后,通过实验加以验证。研究发现强制对流条件下的双面加热能够加快空气热对流速度及沙体传热速度,使沙体层温度分布均匀化,进而提高沙体的传热效率。

Based on different convection numerical simulation and experimental study of heating system

Abstract: By using heat conduction equation of porous media,the DO radiation model and standardturbulence model,establish a three-dimensional thermal physical model.At first,under natural convection conditions, namely sand therapy room in a state of calm,change heating mode,which is single side heating and double side heating respectively.Under different heating methods, comparatively analyze changes of temperature field in air layer and sand layer.Secondly,Under the condition of double heating,change modes of convection,which is natural convection and forced convection respectively.Under different convection methods, comparatively analyze changes of temperature and velocity field in air and sand layer.Finally,apply the experiment to verify.It is found that forced convection can accelerate the speed of heat convection of air and heat transfer of sand, make the temperature distribution of the sand layer uniform, and then improve the efficiency of heat transfer.