Verification of Numerical Simulation Results and Experimental Data of the Cavitation Influence on Hydrodynamic Characteristics of a Jet Flow

The work experimentally studied the regularities of the cavitation influence on hydrodynamic characteristics of a jet flow. The parameters of the change in the total pressure p_t along the axis of the jet, the static ps in its cross section, and the geometry of the cavitation region are determined. The results were obtained on a conical nozzle with an internal diameter d₀ = 2 mm and a length of the cylindrical section at the output l = 4 mm. The pressure applied to the experimental section (at the nozzle inlet) p₀ was 10 MPa, the back pressure in the flooded chamber pk varied from 0.1 to 2.5 MPa. Using the software package ANSYS CFX, the geometry of the model was constructed and the cavitation flow of liquid from the nozzle identical to the prototype was calculated. Comparative analysis of the experimental data and computer simulation results obtained using the ANSYS CFX is made. It is shown that the standard cavitation function of the software complex ANSYS CFX can accurately predict the hydrodynamic characteristics and geometry of the cavitation jet flow. The difference is observed in the intensity of the total pressure drop on the axis of the jet and the distribution of static pressures along its width is most distinct near the nozzle cut at relative distances X = x/d₀ < 2. This region is characterized by the continuous formation of a large number of rapidly moving cavitation bubbles. They explosively grow and then are transported by a thin layer of liquid along the surface of the cavity. In the condition of developed cavitation, there is a strong deformation of the jet flow, which introduces certain discrepancies between the experimental and calculated data. Basically, ANSYS CFX simulation is in good agreement with the experimental data, which allows us to use it in future to analyze the quality of cavitators, and to predict the destructive ability of the cavitation flow

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