doi:
UDK: 532.62 : 614.844.2

NUMERICAL SIMULATION OF JET PROPAGATION IN A SHOCK JET DISPENSER

Иванов А. В., Яковлев А. Ю.
Article language: русский

Annotation

The work is devoted to modeling the process of jet propagation in a shock jet dispenser. Shock jet dispenser are widely used in marine fire extinguishing systems as water sprayers. For a long time, the development of sprayers was carried out experimentally. However, the modern approach to modeling fire extinguishing processes requires a more detailed study of the principles of operation of this type of injectors, which requires the use of modern numerical modeling methods. The process of spraying the jet is quite complex and includes several phases. The purpose of this work is to study the processes occurring in the phase of jet impact into the deflector and the formation of a water sheet. Modeling of the process of disintegration of the sheet into droplets is not performed. The calculation is carried out using the OpenFOAM package. To account for the propagation of a water jet in the air, the Volume of Fluid method is used, the system of equations is solved by the control volume method, the cases of laminar and turbulent flow are considered. The SST model was used to simulate the turbulent flow. Calculations were performed for flat and axisymmetric flow. The grid convergence check has been performed. A comparison with the known analytical solution and indirect comparisons with the experiment were carried out. As a result of the study, it is shown that taking into account the viscosity of the liquid and modeling the turbulent flow have little effect on the magnitude of the forces on the deflector and the shape of the initial section of the sprayed water sheet. Pressure distributions on the deflector surface are obtained and it is shown that they do not depend much on its width. The manifestations of instability in the sprayed water sheet were revealed, which further lead to its disintegration into droplets. Keywords: shock jet dispenser, jet, jet disintegration, liquid spraying, fire extinguishing, CFD calculation, droplet formation, instability, pressure

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