Процес дроселювання в соплових апаратах з поворотними діафрагмами

Abstract

In the process of developing a method for numerically investigating a plane flow around a nozzle array with a rotary diaphragm, calculations were performed for various degrees of opening of the rotary diaphragm δ and pressure drops π on the array. The article presents some results of a numerical study of the flow in the nozzle channel at the degree of opening of the rotary diaphragm δ = (1…0.15). Modeling and calculations of the flow of the working fluid were performed using the Fluent software package. The construction of computational areas, limited by one inter-blade channel, for a different degree of opening of the diaphragm of the nozzle apparatus has been carried out. The grids for the computational domains were constructed. Calculations were carried out for δ = (1…0.15) and for various degrees of pressure drop across the grate. Because of the performed calculations, flow patterns in the interblade channel and behind it, and the distribution of kinetic energy loss coefficients along the grating front at various degrees of aperture opening at the nozzle inlet, were obtained. Based on the results of the work carried out, the following conclusions can be drawn: the operation of a nozzle array with a rotary diaphragm at different degrees of opening of the rotary diaphragm δ and pressure drops π on the grate can be divided in the range of opening steps δ = (1…0.77) as operation in the nozzle mode, and in the range δ = (0.77…0.15) as in throttle mode; when the angle of attack changes, the values of the kinetic energy loss coefficients increase significantly (up to 25 %) only for π = 0.7 and δ = 1; at π = 0.3 and δ = 1, the coefficient increases slightly (up to 0.5 %); at π = 0.7; 0.3 and δ = 0.3, the coefficient increases to 5 %, while the coefficient ζі changes less relative to the coefficient ζ90 at the calculated angle of attack α0 = 90 grids). The results obtained in this work will be used to develop a technique for numerically investigating the spatial flow around nozzle arrays with rotary diaphragms.