Cavitating flow in nozzles is a complex flow which implies a highly turbulent two-phase one. An accurate simulation which improves some numerical results found in the literature was achieved by means of an extensive analysis of the capabilities of several numerical models for turbulence and cavitation. The analysis performed involves calibration/optimization tasks based on the physics of this kind of flow. This work aims to provide a quantitative criterion for the judgment of internal flow state, because it was demonstrated that the numerical results obtained with noncalibrated models could be enhanced by means of a careful calibration and thus saving computational costs.

Cavitation in pressure injectors/atomizers affects the liquid/spray jet behavior at its outlet. The type of atomization induced by cavitation allows developing efficient devices if this cavitation state is controlled. Cavitating flow is related to turbulent and multiphase flows with mass transfer between the liquid and its gaseous phase and which is affected by several factors. Due to the high-speed flow and small spatial and time scales involved, the study of cavitating flows using physical experiments is very expensive. By means of numerical simulations using Eddy Viscosity Models some of the incipient and slight developed cavitating flow characteristics in nozzles are captured, but the level of the vapor fraction is commonly underestimated. It is evident that a suitable calibration of the turbulence models based on the special characteristics of the incipient/slight developed cavitating flows allows obtaining improved results. This special calibration is necessary due to the close relation between the cavitation inception/developing conditions and the turbulence level in the flow leading to a 'non-standard turbulence state'. So, cavitating flows should not be modeled as a simple turbulent one. It is also demonstrated that the results obtained become competitive compared against the ones computed by Large Eddy Simulations which need a lot of computational resources and an appropriate initial solution for running. The conclusions obtained can be useful to improve injector designs, because the suitable simulation of the incipient cavitation or slight developed cavitation flow conditions can be accurately simulated after calibration.