CONVECTIVE-DIFFUSIVE HEAT TRANSFER IN TUBES: ROLE OF THE HYDRODYNAMICS OF FLOW ON THE FEASIBILITY DOMAIN OF THE ASYMPTOTIC TEMPERATURE PROFILES

Abstract In this contribution, an assessment of the role of the hydrodynamics of flow on the asymptotic solutions used to describe convective-diffusive heat transfer in packed-bed and capillary tubes of cylindrical geometry is reported. Such asymptotic solutions are intrinsically dependent from the type of hydrodynamics present in the tubes. They describe the temperature profiles for heat transfer problems found in packed-bed and capillary systems with axial convective and radial diffusive transport and having a constant heat flux at the outer tube wall. The role of the hydrodynamics of the flow on the asymptotic temperature profiles and their feasibility region of validity for both the packed-bed and capillary tube cases were assessed and feasibility ranges identified. A brief comparison of the predictions for the two cases analyzed is also included. The analysis of the impact of the hydrodynamics on the ranges of validity for the asymptotic temperature profiles seems to be first one available.

摘要 本文针对圆柱形几何结构的填充床（packed-bed）与毛细管（capillary tube）内的对流扩散换热问题，报道了流动流体力学特性对用于描述该过程的渐近解（asymptotic solution）的影响评估结果。此类渐近解本质上由管内的流体力学流动类型决定，可用于描述填充床与毛细管系统中，存在轴向对流与径向扩散输运、且管壁外表面维持恒定热流密度（heat flux）的换热问题的温度分布。本文针对填充床与毛细管两种场景，分别评估了流动流体力学特性对渐近温度分布的影响，以及渐近解的有效可行域，并明确了其可行范围。此外，本文还对所分析的两种场景的预测结果进行了简要对比。本次针对流动流体力学特性对渐近温度分布有效范围的影响分析，为目前公开报道的首例相关研究。