Чисельне дослідження обтікання соплових решіток з поворотними діафрагмами

Abstract

Представлені результати чисельного дослідження плоского обтікання соплової решітки з поворотною діафрагмою, виконано порівняння результатів розрахунків з експериментальними даними. Розрахунки виконувалися за допомогою програмного комплексу Fluent (№ клієнта 01067322). В результаті виконаних розрахунків були отримані: картини течії у міжлопаточному каналі і за ним; розподіл коефіцієнтів втрати кінетичної енергії по фронту решітки при різних ступінях відкриття вхідної частини каналів соплової решітки.The purpose of one of the stages of this research is to develop the technique for the numerical investigation of the flow of the nozzle array equipped with the grid valve for its further use for the solution of the problem relating to the optimal design of the flow passage in cogeneration turbines. The development of this technique was divided into two parts, in particular the simulation of the two-dimensional or flat flow and the simulation of the three –dimensional flow. This research paper gives some data obtained for the first part of the developed technique, i. e. the verification data obtained by the comparison of the results of numerical and experimental investigations of the twodimensional flow of the nozzle array with the grid valve. The Fluent software package was used for the simulation and computation of the flow of operating fluid. Computational domains restricted by one interblade channel were constructed for a different degree of the opening of the nozzle closure diaphragm. The grids were constructed for computational domains. The computations were performed to define the effect of the used turbulence model on the computation results. The best coincidence with experimental data was obtained when using the k–ω SST model. The computations done allowed us to obtain the flow patterns in the interblade channel and behind it and the distribution of the coefficients of the loss of kinetic energy over the grid front for a different level of the opening of closure diaphragms at the inlet to the nozzle ring. The obtained research data allow us to draw the following conclusions: the selected computation parameters enable a qualitative reflection of physical phenomena in the flow both for subsonic and supersonic flows of the cascade; the computation coefficients of the loss of kinetic energy showed a satisfactory coincidence with experimental data and it is indicative of that the development of the technique for the numerical investigation of the flow of nozzle arrays with grid valves is possible in principle when using the Fluent software package. The data obtained through this research will be used for the development of the technique for the numerical investigation of the three-dimensional flow of nozzle arrays with grid valves.