Analysis And Optimization Of Turbulent Model In Vehicle External Flow-field Base On Ideal Body

Since the late year 2008, China has become the largest consumer and the third largest producer in the world's automobile market, while it is still not powerful enough in the research field, especially in automobile aerodynamics, which falls far behind the western countries.At present, the method of computational fluid dynamic, becoming the more and more important tool in automobile aerodynamics, has been widely used in the automobile development.In this paper, it studies the fundamental theory of CFD, and gives brief introduction of ordinary two equations turbulent model like standard k ?εmodel, RNG model, SST model, V2F model, and LES turbulent model and often-used discretization form.And then it generally introduces the STAR-CD, a kind of commercial CFD software, and makes contrast of several grid types. Based on the ideal body CAD model, it builds CFD grid computing prototype, and applies four kinds of turbulent models such as STAR-CD standard k ?εmodel, RNGk ?εmodel, SST model and V2F model into the ideal body's external flow field calculating analysis at different speeds. It focuses on these four kinds of models' performance in convergence characteristics, resistance characteristics, flow field characteristics, and makes contrastive analysis of the four models in the performing difference under the different speeds and calculating results. According to the above, it puts forward the view that selecting different turbulent models in the different situation.In the application of automobile external flow field, selecting V2F model as the research object, with the contrastive results' analysis of the four kinds of turbulent models, it studies different parameters' effect on different calculating results and improves all specific aspects respectively. In a word, the statement in this paper would be beneficial to the need of automobile external flow field analysis as a theoretical support.