Research On Added Mass Of Vehicle Running With Cavity Based On Numerical Method

In engineering practice, it is necessary to master all the force conditions of vehicle toforecast its motion characteristics, in order to control the vehicle with high speed. Theemergency and development of cavitation would induce the complicated multiphase flowfields, so it is difficult to calculate the exact value of added mass with experiments andclassical theory of potential flow. Based on Reynolds-Averaged Navier-Stokes equationsand Mixture-multiphase model in software FLUENT, a numerical study of a vehicle with aproper stimulation after the flow fields being steady is presented to calculate the addedmass with the numerical method to deal the monitor curves of forces and moments.Before research，setting the all-wetted added mass of conventional numericalexamples identifies the feasibility of research method，and calculating the moving diskwith cavity proves the reliable of research method. Based on the strict analysis anddemonstration of the stimulation coefficients, this study begins the numerical simulationof two groups of models. Firstly, the research is established on viscosity condition tocalculate the added mass of cylinder with half-sphere head. With a lot of simulationexamples, the relations between added mass and cavitation numbers (relative cavity length)are carried out, which are divided into some of sections. Meanwhile, using inviscid modelstudy the influence of phase excursion to added mass value. Secondly, set the comparisonexample to study the added mass of cylinder for different cavitation numbers. Then, studythe numerical relation between λ26and λ22to identify the theory relation of these twovalues. At last, the research gives the difference of added mass between two groups ofmodel for different cavitation numbers.Through contrastive study of two groups of simulation examples，it is found thatrelation between all the coefficient of added mass and cavitation numbers could be divided into four sections，and different coefficients own different range. When the section isdivided by relative cavity length, the added mass could be evaluated with section cuttingmethod based on potential flow theory. This paper investigates the added mass withseparated sections, which could get rich conclusions and valuable results.