| In order to overcome the difficulty of grid generation in solving the heat-moisture coupling transfer model of wall with traditional numerical methods,an accurate and stable meshless numerical solution based on generalized finite difference method is proposedFirstly,the heat-moisture coupling transfer model with temperature and relative humidity as the driving force is selected,and the spatial and temporal terms of the thermally and humid coupling transfer differential equation are discretized by generalized finite difference method and implicit finite difference,respectively,and solved by Newtonian iterative method.Taking the HAMSTAD verification example as an example,the calculation results are compared with the analytical solution and other numerical solutions to verify the accuracy of the algorithm.The calculation results of the single-layer wall show that the solution results are highly consistent with the analytical solution,and the average relative errors between the moisture content results and the analytical solution at 100 h,300h and 1000 h are 0.097%,0.079% and 0.055%,respectively.The calculation results of the multi-layer wall show that the solution is in good agreement with the results of the finite difference method under the same model,and the maximum relative error of relative humidity is 0.58% and the maximum relative error of temperature is 0.32%.Taking the temperature and humidity potential as the driving force of the heatmoisture coupling transfer model as an example,the total area points,subregion selection points,time step size and weight function of the influence algorithm are analyzed in detail by the control variable method,and the results show that the changes of these parameters have little effect on the calculation results,and the average relative error with the analytical solution is less than 0.1%.Then,the influence of disturbance parameters on the algorithm is analyzed,and the calculation results show that the average relative error between the temperature calculation result and the no disturbance is 0.058%,the average relative error between the humidity potential calculation result and the no disturbance is 0.612%,the average relative error between the temperature calculation result and the no disturbance is 0.39% in the case of data error disturbance,and the average relative error between the humidity potential calculation result and the no disturbance is 0.62%.Finally,taking Nanchang area as an example,the algorithm proposed in this paper is used to solve the the heat-moisture coupling transfer model,and the heat transfer characteristics of multi-layer composite walls in Nanchang area are analyzed.The simulation results show that the heat flux on the outer surface of the wall considering the heat flux of the wall in the process of heat and moisture transfer is higher than that calculated by pure thermal conduction,and the heat flux on the outer surface of the wall in the east,west,south and north directions is 15.7%,11.97%,16.7% and 12.9%higher than that of pure thermal conductivity,respectively.The average heat flux of the east and west exterior walls is higher than that of the north and south facing walls,and the latent heat flux of the external surface of different facing walls accounts for about9.15%～13.25% of the total heat flux. |
