Analysis And Mechanism Research On Hydroplaning Performance Of Bionic Tire Tread Groove Based On Fluid Structure Coupling

When the vehicle is driving at high speed on the road with stagnant water,the stagnant water flowing through the tire grounding area will not be able to be discharged from the groove in time,causing hydroplaning,which seriously threatens driving safety.In order to increase the critical hydroplaning speed and improve vehicle safety and operational stability,many scholars have studied tire hydroplaning based on the characteristics of the pattern structure.However,pattern structure has important influence on many properties of tire.Improving hydroplaning performance will also cause other performance loss.Therefore,it is of great significance to study the characteristics of tire flow field without changing the tread pattern structure.Based on the concept of bionic non-smooth drag reduction,the bionic non smooth structure is applied to the bottom of complex tire groove to achieve the purpose of improving the anti-hydroplaning performance of the tire without changing the other properties of the tire.Based on the theory of tire fluid dynamics,this paper takes the 185/60 R15 complex pattern tire as the research object,and establishes the tire-road shell model based on the ANSYS Workbench platform.The rationality of the model is verified by comparing the simulation results of tire static loading with the test data.On this basis,the fluid domain model of tire is established,and the two-way fluid structure coupling simulation of tire hydroplaning is carried out by using computational fluid dynamics method,and the effectiveness of hydroplaning analysis method is verified according to the empirical formula of critical hydroplaning speed.Based on the principle of bionics,the scale shield groove on the surface of shark skin is selected as the research object,and the non smooth structure of the bottom surface of the single pitch longitudinal pattern groove is designed.Three groove forms are obtained,and the size parameters are determined by combining with the theory of boundary layer thickness formula.Through Fluent software simulation analysis,the drag reduction characteristics of each groove structure under different water velocity are obtained.The results show that the three kinds of non smooth grooves all have the effect of drag reduction,among which groove I has the best drag reduction effect,groove II takes the second place,and groove III is the worst;with the increase of speed,the drag reduction of each groove first increases and then decreases,reaching the best at 90 km/h.At the same incoming flow velocity,related physical amounts such as shear stress,flow speed and exercise energy of the flow field on the non smooth groove surface were analyzed,and the resistance mechanism of bionic prosthetic limbs was explored.The existence of bionic non smooth groove can affect the internal structure of the boundary layer,increase the thickness of the wall boundary layer,reduce the velocity gradient of the viscous bottom layer,restrain the development of turbulence near the wall,reduce the energy loss of the fluid,improve the mainstream velocity of the groove,and increase the drainage.In order to analyze the overall influence of bionic non smooth structure on tire hydroplaning,the groove with optimal drag reduction was applied to the bottom of tread groove to optimize the original tire design.Compared with the original tire,the bionic tire can effectively reduce the hydrodynamic pressure on the tire surface,improve the tire hydroplaning speed,and ensure the driving safety of the vehicle on the wet road.