Чисельне дослідження впливу зміни кута атаки на величину коефіцієнта втрат кінетичної енергії та кутів виходу потоку для соплових решіток з поворотними діафрагмами

The goal of one of the steps of this research is to develop a technique for numerical study of the flow around a nozzle array with a rotary diaphragm, for its further use for solving the problem of optimal design of the flow part of heating turbines. Due to an ample amount of numerical studies, the development of the methods is divided into several parts. The paper presents some results of numerical studies of flat flow around a nozzle array with a rotating diaphragm at angles of flow entry into the array of S-9013R profiles different from the calculated angle of attack equal to 90°. Modeling and calculation of the flow of the working fluid was performed using the Fluent software package. The construction of computational domains restricted by one interblade channel was carried out for different degrees of opening of the diaphragm of the nozzle apparatus. Grids for computational domains have been constructed. Calculations were carried out for the angles of entry into the profile grid in the range of 45º to 135º. The calculations done enabled the generation of flow patterns in the interblade channel and behind it, and the distribution of kinetic energy loss coefficients along the front of the array at various degrees of opening of the diaphragm at the entrance to the nozzle apparatus. Based on the results of the work done, the following conclusions can be drawn: a change in the angle of attack affects the distribution of static pressure along the profile only in its front part, and does not affect the distribution in the output part; a change in the angles of attack does not affect the exit angles from the nozzle array of S-9013R profiles; a decrease in the pressure difference across the nozzle array results in a change in the exit angles from the nozzle array at an opening degree of the rotary diaphragm of π > 0.5.