Research On Flow Field Analysis And Thermal Comfort Of RV Based On CFD

With the development of China's automobile industry and the improvement of national living standards,more and more people have begun to choose the RV as a way of travel.The RV has two types,trailer type and self-propelled type.It has the functions of “room” and “car”.It is a mobile vehicle that provides the functions of living and living.In the past ten years,China's RV industry has developed in an explosive manner,and RV ownership and RV camps have experienced rapid growth.However,the current domestic regulations on RV are not perfect enough to form a unified industry standard.There are a few researches on RV in China,and there are still some shortcomings such as unreasonable internal space design,low comfort and poor stability.In view of this situation,this paper takes into account the space utilization and driving stability.A common internal three-space layout is analyzed for a towed RV.And we use the Computational Fluid Dynamics(CFD)method to study the flow field and thermal comfort of the RV for the first time.The analysis results hope to play a guiding role for the RV enterprise to improve the utilization of the interior space and improve the thermal comfort of the RV.The main research contents are as follows:Firstly,the current layout of the interior space of the RV is analyzed and compared.Taking a type of towed RV as the research object,a three-dimensional model of the towed RV is established,and the heat transfer characteristics of the RV compartment are analyzed in summer.The cooling load of overhead air conditioning is calculated,and the cooling capacity of RV air conditioning is matched.Secondly,the three-dimensional grid computing model is established after simplifying the RV model,and the flow field boundary and thermal boundary conditions of the thermal environment simulation in the RV are discussed.The orthogonal test method is used to design a variety of working conditions for simulation,and the influence of the air supply parameters is analyzed.The calculation results clearly show the dynamic process of natural warming inside the RV and cooling after the air conditioner is turned on in summer under high temperature..Thirdly,on the basis of the above research,the FLUENT software is coupled to ISIGHT platform to establish a radical basis function neural network approximation model.The NCGA genetic algorithm is applied to the multi-objective optimization design of air supply parameters in the interior flow field of RV.The process of automatic simulation optimization from DOE test design,fluid simulation,approximate modeling to algorithm optimization is set up.This method can quickly and accurately obtain the optimal air supply parameters of air conditioning and improve the optimization efficiency.Finally,the PMV-PPD index is used to analyze the influencing factors of thermal comfort inside the RV.The CFD method is used to simulate and visualize the comfort of the thermal environment inside the RV.And the airflow organization is evaluated by the unevenness coefficient and the air diffusion performance index.It is found that the internal thermal environment of the RV can basically meet the thermal comfort requirements.