Feature investigations for concentrated gas-drop flow within a nozzle of a pilot plant by means of numerical and full-scale experiments

Аuthors

Tsipenko A. V.

Moscow Aviation Institute (National Research University), 4, Volokolamskoe shosse, Moscow, А-80, GSP-3, 125993, Russia

e-mail: tsipenko_av@mail.ru

Abstract

A numerical simulation is carried out for a two-dimensional gas-drop nozzle flow with a significant portion of liquid fraction in it. This sort of the flow occurs in a knapsack fire fighting equipment developed at the MAI. A model used for simulation takes into consideration a presence of a film, collisions and aerodynamic fragmentation for drops. A multifluid approach and particle-in-cell method are realized in the model. It is proved numerically and experimentally for high concentrated gas-drop flow that the nozzle operates like a peculiar «mill» breaking drops. Other obtained results include: the film is very stable for subsonic fluid velocities; it is exist increased fluid content and gas pressure near nozzle exit section; a zone exists near a wall within expanded part of the nozzle with an inclusion volume fraction which is significantly lower than average value for the flow. The results obtained demonstrate suitability and usefulness of the model to solve problems concerned with numerical investigation and prediction of gas-drop flows.