Computational Fluid Dynamics Simulation of High Speed Jet Under Different Input Pressures

The aim of this study is to execute the computational fluid dynamics (CFD) simulation of high speed jet under different input pressures (i.e., 80, 120, 160, 200, and 240 MPa). In particular, this study focuses on the pressure distributions and streamlines of the orifice in high speed jet, primarily because the orifice plays a role in accelerating the flow of liquid, having significant effects on the working performance of high speed jet. Firstly, the two-dimensional geometric model of high speed jet is established on the basis of the actual operational conditions. Next, the unstructured grids of high speed jet are generated by means of ICEM CFD 16.0. Virtually, the computational fluid dynamics simulation of high speed jet is a two-phase flow (gas-liquid) problem, so the homogeneous (Eulerian-Eulerian) two-phase model is employed to carry out the gas-liquid interaction. Particularly, the turbulent flow computation of high speed jet is carried out with procedures based on the Reynolds-averaged Navier-Stokes (RANS) equations. As the flow of high speed jet is highly turbulent, the RNG k-ɛ turbulence model derived by Yakhot et al. (1992) is utilized in this study. Finally, the computational fluid dynamics (CFD) simulation of high speed jet is implemented by using the CFX-Solver in ANSYS CFX 16.0. The simulation results show that when liquid flows through the orifice, the pressure of flows decreases swiftly, whereas the velocity of flows skyrockets to the maximum value and then decreases slightly. In addition, the relationship between the working pressure and input pressure and the relationship between the working velocity and input pressure are achieved, which could provide certain theoretical guidance for predicting the working pressure and velocity of high speed jet based on real input pressures.