Numerical Simulation And Analysis Of Flow Field In A Car Compartment

The distribution of flow field in the car is directly related to the comfort experience of drivers and passengers,and indirectly affects driving safety.In addition,the internal structure of the car is complex and the gas flow is very irregular.How to make the distribution of flow field in the car meet the requirements of human comfort is a challenging and significant research topic.Using the method of computational fluid dynamics to simulate the flow field in the car can present the distribution characteristics of the flow field intuitively and effectively,so as to study the distribution characteristics of the flow field in the car and its influence on human comfort.In this paper,a car is taken as the research object,exploring the influence that the three air supply parameters such as air supply speed,air supply temperature and air supply angle make on the flow field inside the car.Firstly,this paper states the numerical simulation method and mathematical calculation model concerning to the interior flow field of car.And analyzing the heat transfer characteristics in the car interior according to the characteristics of the air flow in the car interior,which lays the theoretical foundation for the numerical simulation analysis.Then,establishing the physical simplified model of the car interior in Solid Works and meshing the model setting boundary conditions in STAR-CCM+.And conducting numerical simulation for interior flow field of car under different temperature,speed and angle condition.Next,the velocity and temperature distribution nephogram of the important position section is intercepted for qualitative evaluation to research out the best air supply scheme of the car and the influence rule of different air supply parameters on the flow field in the car and the comfort of human.Finally,the air distribution and comfort degree in the car under different air supply parameters are evaluated objectively and scientifically adopting the air distribution evaluation index.And on the hand,the accuracy and rationality of the conclusions from the qualitative evaluation are proved.On the other hand,the influence law of different air supply parameters on the air distribution evaluation index is obtained.It is found that the conclusion of qualitative and quantitative evaluation is consistent,which not only proves the feasibility of air distribution evaluation method,but also ensures the accuracy of the conclusion.It is concluded that the best air supply scheme for this car in summer is as follows: the air supply speed and temperature of the middle air supply outlet are 4m/s and 292 K respectively,the air supply speed and temperature of the air supply outlets on both sides are 3m/s and 289 K respectively,andthe air supply angle is 15°.The air supply speed and angle have an great influence on the speed field and temperature field of the car room,and the air supply temperature only influence the temperature field.The air distribution in the rear row can be improved by reasonably adjusting the air velocity and temperature of the middle air supply outlet,so that the air distribution in the whole compartment is more uniform.The proper oblique upward air supply can reduce the front seat’s block to the air flow,enhancing the air flow of the rear row and improving the comfort of the rear row passengers.When the air supply is inclined downward,the air flow in the whole car room is poor,which will not only affect human comfort,but also waste energy.The air supply parameters can be changed reasonably to reduce the nonuniformity coefficient and improve the ADPI value,so that the air distribution in the car room can be more uniform and comfort is better.The research results will provide certain reference and basis for the design of air distribution in car interior,the design and use of air conditioning,which has theoretical significance and practical application value.