COMPUTATIONAL MODELING METHODS IN DESIGN OF IRRIGATOR WITH WATER SPRAY

The study investigated the utility of computational hydrodynamics application to design of irrigator for water spray fire-extinguishing system. Main principles of turbulent flow models used in modern hydrodynamic analysis were presented in the article: URANS (Unsteady Reynolds Averaged Navier–Stokes) and LES (Large Eddy Simulation). Main assumptions underlying most turbulence models were described. Main problems of initial and boundary conditions for specified equation classes were presented and ways to resolve them were proposed. Ways to describe liquid flow in wall-adjacent area were introduced. Experimental calculations for irrigation flow with these models were described for practical example with water spray irrigator in fire-extinguishing systems. The calculations for irrigator flow were performed with the models mentioned above; method VOF (Volume of Fluid) was used. The aim of the experiment was to show irrigator characteristics, which shape and parameters were determined by experimental data. The experiment demonstrates unprofitable cost of LES-model, while URANS-model provides acceptable cost value. Experimental and calculated parameter comparison proves that computing modeling provides adequate prediction for complex biphasic flow and can be used for hydrodynamic design of water spray irrigators.