中文摘要：

为了研究室内环境中热、湿以及挥发性有机化合物（VOCs）的分布特征，根据不可逆过程热力学基本原理，考虑交叉耦合扩散效应的影响，采用数值模拟方法研究了室内环境中同时存在温度梯度、水蒸气浓度梯度和VOCs浓度梯度时的自然对流传热传质现象，展示了流场、温度场和浓度场随浮力比的变化状况，着重讨论了热扩散效应、扩散热效应和质附加扩散效应对无量纲传热努谢尔特数和传质舍伍德数的影响特性。研究表明，多物理场中交叉耦合扩散效应对自然对流传热传质具有一定的影响。

英文摘要：

Based on the principle of thermodynamics of irreversible processes and cross coupled diffusive effects, a mathematic model was developed to analyze the characteristics of natural convective heat and mass transfer processes in the multi-physical field. The model was solved by the FEM method for the conditions of when tempera- ture gradient, VOCs concentration gradient and water vapor concentration gradient were present alone and in combi- nation; the simulated profiles of the dimensionless velocity, temperature and concentration are presented for the corre- sponding cases. Coupled diffusive effects on the diffusion of VOCs in indoor environment are discussed based on the simulation results. Finally, the average Nusselt number and Sherwood number are depicted graphically to illustrate the cross diffusive effects. The results show that the coupled diffusive effects should be taken into consideration in modeling the heat and mass transfer phenomena.