Abstarct: It is important to prevent the occurrence of cavitation in internal flow such as valves and pumps, however in external flows This phenomenon has many advantages Including through the formation around a vehicle, reducing the frictional drag on it because of the reduced viscosity of vapor phase, one of the main reasons for the use of cavitation for natural or artificial underwater projectiles. This thesis is to study the cavitation and comparing simulation models in the development of cloud cavity and its impact on the flow and the results compared with experimental results. Firstly, the definition of cavitation and the basic equations for the analysis of this phenomenon is shown in and finally introduced Mass transfer models used in this phenomenon. In the numerical study, in Beginning transient cavitation simulation models have been introduced, and three popular models for this field , ie, models Kunz, Singhal and Zwart Have been selected and then, for each a numerical code has been provided, and the strengths and weaknesses of each model has been studied. Numerical simulations carried out in this project to assess the strengths and weaknesses of these models is on the internal and external flows. To achieve this purpose, a venturi and an orifice for cavitation on the internal flow and one hydrofoil NACA0015 for cavitation on the external flows with different attack angles, consistent with experimental results has been performed. According to the results the best model for internal flows is Zwart model, but can not be ignored a good ability of Kunz model in numerical analysis for internal flows. Also in this models for analysis of the external flows, the overall results were pretty close together and no one has not advantage, but in the end, select the Kunz model for investigation is recommended of the numerical solutions obtained in this model. And then for more accurately simulate addition the temperature in the numeric codes, to selective mass transfer models have been developed. In the case of mass transfer models assumed that the critical pressure of the solution is constant and in actual it is a function of temperature. By adding the equation of August-Magnus the effect of temperature; models have the ability to refine a critical pressure proportional to the temperature at which it is located, was created. Finally, a comparison between the results from the numerical solution of these models by adding the effect of temperature and the results of numerical models without affecting the temperature with experimental results for parameters such as pressure ratio and discharge coefficient performed. Adding this ability to solvers improved results compared to non-thermal effect and results in higher accuracy compared with other reported results. Numerical simulation of cavitation with programming language C++ under Linux and then for run numerical codes, OpenFoam software was used.