Numerical Simulation Of Flow Field Around A Light Truck Analysis And Design Optimization

Automobile safety, energy saving and environmental protection has become thethree themes of the auto industry development in the future. Aerodynamiccharacteristics of automobile have a direct impact on power performance, fuel economyand automobile safety. In the study of aerodynamics, how to reduce the aerodynamicdrag of vehicles is an important research content. At present, the aerodynamic dragcoefficient of vehicles in our country still has very big improvement space. At the sametime, in order to meet the demand of faster van practical speed, higher transportefficiency and to achieve the requirements for energy saving, emission reduction,environmental protection, people gradually pay more attention to the research of thevans’aerodynamic characteristics.At present, the researches on aerodynamic characteristics of cars, buses,high-speed trains, and planes have been more deeply at home and abroad. People whoengage in the research of truck drag reduction adopt aerodynamic additional devices toreduce the truck running resistance. In this paper, I put a certain type of domestic lighttruck as the research object. The next work includes setting up the geometrical model,the establishment of the finite element model and numerical simulation analysis withCFD software STAR-CCM+. Through my simulation analysis, there is some obviouspositive pressure area existing in the height difference between cab and van container.And this obvious positive pressure area is the key part for aerodynamic optimization inthis paper. I perform numerical simulations of the model which is equipped withaerodynamic additional devices at the top of the cab. The aerodynamic additionaldevices include air deflector and well type grilles. The experimental results show thatboth of the two devices can make light truck aerodynamic drag fell dramatically. Themost critical part in this article is optimizing the size of the air deflector’s position. Inorder to find the optimal size of the air deflector, I design the experiments about the twoparameters determining the size of air deflector according to Latin Hypercube Sampling.After all of this experiments, the optimal result is aerodynamic drag coefficient of0.5486.Then I make experiments about the size of well type grilles with the algorithmsame to the size of air deflector. Eventually I get the optimal model with the truckrunning resistance reduced9%than that of the original model. In this article, the drag reduction effects of the two additional devices areresearched and analyzed. After simulation test and data processing based on LatinHypercube Sampling, it finally gets the size of drag reduction devices which providesreference basis for future design.