Analysis On Pressure During Door Closure Considering Air Tightness

With the rapid growth of China's economic strength,people's requirements for traditional vehicle tools have become higher and higher.Not only do they need to have high safety and rich functional configurations,but they are also increasingly high expectations.In real life,with the improvement of the sealing performance of the whole vehicle,when the passengers are in the vehicle,when the door is closed,the pressure at the ear is too large,and the phenomenon of dizziness and chest distress occurs.Seriously affect the passenger's ride experience and safety and comfort.Therefore,it is of great significance to analyze and research this issue and propose related solutions.During the closing of the door,a large amount of gas intrudes into the passenger compartment with the rotation of the door,and the incoming gas cannot be completely discharged outside the vehicle due to the limited leakage path of the vehicle body.This caused the passenger cabin pressure to rise rapidly.This problem is more noticeable in vehicles with a high degree of tightness and a small passenger compartment volume.At the same time,because the later experiments and structural improvements require more time and economic costs,it is necessary to establish a high-precision model simulation and closing process through the CAE method.This paper uses a small-scale electric parking space analysis object and proposes a new modeling method for the door closing process through the CFD software Star CCM.It simulates and verifies the sealing properties of the vehicle when the door closing simulation is performed..First of all,through the vehicle's air tightness test on the vehicle under study,combined with theoretical derivation and simulation analysis,the use of porous media area to replace the energy loss at the pressure relief valve and body sidewalk cavity,reversed the inertia of porous media.Resistance coefficient and viscous drag coefficient.By comparison,it was confirmed that the sealing performance of the simulation model is consistent with the experimental data.Then based on this,the vehicle door and the vehicle are modeled in detail,and the boundary conditions and physical conditions of the model are obtained according to the actual state of the door closing process.The flow field characteristics and pressure variation curve of the door closing process are obtained through calculation.Compared with the closing ear pressure testing instrument,the change trends of the two are the same,and the peak pressure error is within 25%.Finally,the method of relieving the pressure inside the vehicle was analyzed from the perspective of the pressure relief valve.The resistance characteristics,area size and arrangement position of the pressure relief valve were discussed respectively.It has been found that reducing the pressure-relief valve resistance characteristics and increasing the hole area of the pressure-relief valve have a significant effect on reducing the internal pressure of the vehicle.Within a certain range of arrangement,the pressure inside the pressure-relief valve has little effect on the vehicle interior pressure.