| The performance of aerodynamics is one of the most important characters of the vehicle,because it affects the vehicle dynamic,fuel consumption,handling stability,comfort and safety of the vehicle.In motorsports,the aerodynamic performance has become the important index of the evaluation of racing car performance.This thesis put forward the design theory and verified the aerodynamic performance of the new racing car aerodynamics attachment.In addition,it explored how the interaction of different aerodynamic attachments affects the aerodynamic characteristics,and studied the flow mechanism of the complex mixed flow formed after the car is added with the aerodynamic attachments.To study the aerodynamic characteristics of the new racing car aerodynamic attachments,there are three aspects of work: the numerical simulation,wind tunnel test of model,and numerical simulation of reproduced wind tunnel.In the numerical simulation,a multiple-attack-angle rear wing,active-air-intake front splitter and new diffuser are designed for a race car.To build virtual wind tunnel and determine the grid strategy which is required for numerical simulation.The model and model combination with different aerodynamics attachments are numerically simulated.On the basis of the results of numerical simulation,by analyzing the flow mechanism of the complex mixed flow formed after the model is added with the aerodynamic attachments and the change of aerodynamics characteristics,it can lay the foundation for the following wind tunnel experiment.In the wind tunnel test,the 3D printing technology is used to produce the physical model for the experiment.Setting up the test bench based the car under real driving cycle,and then the wind tunnel test is carried out for the original model and model combination to obtain the aerodynamic data of all models.The flow-state on the surface of car body is measured by oil-flow visualization technology.Next,the accuracy of numerical simulation results and the efficiency of aerodynamic attachments are verified by comparing the results of wind tunnel test and numerical simulation.In the numerical simulation of reproduced wind tunnel,by reproducing the wind tunnel numerical simulation technology,the wind tunnel test is modeled,and the boundary conditions in the wind tunnel test are restored.After that,a virtual wind tunnel is established in accordance with the actual wind tunnel test conditions.Numerical simulation is used to analyze the influence of the support rod and the test bench panel,and the change of the flow field in the supporting equipment is studied on the vehicle wind tunnel test.The changes in the operating efficiency of new aerodynamic attachments under the influence of supporting equipment are analyzed.In this thesis,the new aerodynamic attachments are studied by using the way of numerical simulation and wind tunnel test as well as numerical simulation of reproduced wind tunnel,which provides a reference for the design of the aerodynamic attachment in the future. |
