Study On Dynamic Characteristics Of Space Thermal Environment Of Automobile

With the development of economy and the improvement of people’s living standard,the car has become an indispensable part of people’s life,the time people stayed in the car is becoming more and more long.As the car gradually increased comfort requirements,thermal comfort inside the car passenger space is more and more attention.Due to the car’s internal space is narrow and relatively closed,if the comfort of the inner environment is poor,it will lead the driver which drove for a long time feel fatigued,absent-minded,irritated and bury a serious hidden danger to all kinds of traffic accidents.Therefore,The research on the dynamic characteristics of the car ride space thermal environment and the thermal comfort of occupants,will help to improve the comfort of the car inner environmental,then reduce the probability of accidents.In view of the research on the dynamic characteristics of the ride space thermal environment of the car is not very system,no consideration for the non-uniform temperature of the car body and the external environment factors(solar radiation)effects on car and other issues,this paper exert the related theoretical knowledge of computational fluid mechanics and heat transfer theory,used the FLUENT software to study the dynamic performance and occupant comfort of the ride space thermal environment.The main research content is as follows:(1)Analyzed the impact properties of spacial thermal environment of car rides.Analyzing fundamental nature of air movement as well as concluding the universal control equation of fluid motion;studying heat passing theory of car rides space,inferring basic principles and equations like heat conduct involving the heat transfer of car rides space,convection heat exchange and heat radiation,and calculating conduct heat resistance and convection heat exchange ratio of multilevel body;adding sun radiation model and using algorithm of tracking ray as an alternative.(2)Analyzed the dynamics of spacial thermal environment of car rides.Firstly,the three-dimension automobile room CAD pattern is built,human body model is added,and networks are divided.Take the city of Chongqing as an example,FLUEN is used to calculate during two phases(the warming and the cooling),then we analyze the changing characters of body surface and inside heat environment at two stages.In order to analyze the radiating bearings on heat environment within,the paper,in 28 cases,analyzes the impacts from different situations:the sun radiates from nothing,the radiating intensity and the incident angles change constantly.The result suggests:the height of internal heat environment doesn’t change in an even and constant way;in summer,the radiation greatly affects automobile body surface and internal air temperature field,thereby affect occupant thermal comfort(3)Evaluated traveling comfort of spacial thermal environment.With the purpose of exploring methods and effects of decreasing the impact on internal heat environment caused by radiation through changing optical property of window glass,we calculate respective equivalent temperature of each section by means of equivalent temperature evaluation index.The result shows that changing optical property of window glass is efficiently able to lessen the effects;for the sake of exploring the bearing on dynamics alternation of interior heat environment dynamics alternation results from automobile air inlet parameter(air supply temperature and speed),6 sets of air inlet parameters are selected for simulation.Seeking best air inlet parameters is based on equivalent temperature evaluation index so as to meet the requirement of creating a comfortable internal heat environment which saves energy.