毕业论文移动版

摘要多孔介质广泛存在于人们的生活的各个方面，并运用于生产中。比如土壤的营养的吸收以及保温、石油开采过程以及食品的干燥过程等。以及本文主要探究的一些工业方面的毛细过程和蒸发流动，本文的主要研究内容如下：86026

（1）首先建立两种多孔介质模型，如为纤维多孔模型和烧结颗粒多孔介质。通过软件模拟的方法来观测以上的两种模型可得：无论其内部是球型颗粒还是圆柱状颗粒，当由其所组成的多孔介质模型的孔隙率相同时，多孔介质的换热情况基本保持不变，所以多孔介质的换热情况与颗粒类型没有关系，其主要受到孔隙率的影响。在流体以恒定的温度进入多孔介质条件下，流体截面的温度变化情况为随多孔介质的孔隙率的增大先变大后变小。

（2）结合多孔介质和传热的一些相关知识，由GAMBIT建立烧结颗粒模型和纤维多孔介质模型并且用FLUENT软件进行数值模拟，研究和分析了多孔介质中颗粒形状、流体进入多孔介质的温度、流体的速度对多孔介质传热特性的影响，进而研究不同形状（烧结颗粒状和纤维多孔状）的多孔介质的对流传热特性。其中突出研究了温度、速度、孔隙率对多孔介质温度平衡的影响，发现当流速增大时，多孔介质颗粒和流体之间能更快的达到平衡温度，且随着速度的增大，平衡温度逐渐下降。然后比较了烧结颗粒多孔介质和纤维多孔介质在相同温度或者相同流速下的传热特性，发现在相同的流速下，两种模型达到平衡的趋势基本相同，但是纤维多孔介质传热效果更好。在研究孔隙度对多孔介质的影响时，主要研究它们对出口温度以及各个孔隙率不同的截面温度的影响，发现随着孔隙度的增加，流体的温度变化幅度没有明显变化，并且传热效果减弱。且如果孔隙率过大，反而可能会削弱传热效果，达不到强化传热的效果。

毕业论文关键字：纤维多孔介质；烧结多孔介质；孔隙率；传热特性

Abstract Porous media exist widely in our lives, and are used in various aspects of production。 For example, the absorption of soil nutrients and heat preservation, oil extraction process and the drying process of food, etc。。 this paper mainly explores the some aspects of the industrial process and the capillary evaporation flow, The main research contents of this paper are as follows ：

（1）Two kinds of porous media models are established, such as fiber porous media and sintered porous media。 By means of software simulation model to observe the above two kinds of available,Whether it is spherical or cylindrical particles,When the porous media consisting of the same porosity,The heat transfer of porous media is basically unchanged。 So the heat transfer of porous media has nothing to do with particle morphology and it is mainly affected by the size of the porosity。 In the condition of constant temperature of fluid entering the porous medium, When the porosity of the porous medium increases, the temperature of the fluid section increases first and then decreases。 

（2）Combined with some knowledge of porous medium and heat transfer, Using GAMBIT established the sintering granular model and fiber porous medium model and the numerical simulation was carried out by FLUENT software, The research and analysis of the influence of particles in porous media properties, fluid temperature, fluid velocity on the heat transfer characteristics of porous media has been taken,and the convective heat transfer characteristics of porous media with different shapes (sintered granular and fibrous porous) are studied。 Which highlights the influence of temperature, velocity and porosity of porous medium temperature balance, it is found that when the flow rate increases, the porous medium particles and the fluid can reach the equilibrium temperature more quickly，and with the increase of the velocity, the equilibrium temperature gradually decreased。 When the heat transfer characteristics of sintered porous media and porous media at the same temperature or flow rate were compared，people found that when they were at the same flow rate, the trend of the two models to achieve equilibrium is basically the same, but the effect of heat transfer in porous media is better。 In studying the effect of porosity on porous media, the effects of the temperature on the outlet temperature and the temperature of the different porosity section were highlighted。 Studies found that with the increase of porosity, the change of the temperature of the fluid becomes slower, and the heat transfer decreases。 And if the porosity is too large, it will weaken the effect of heat transfer and can not reach the effect of heat transfer enhancement。  (责任编辑：qin)