Вплив форми дозвукової частини надзвукового вхідного пристрою на коефіцієнт збереження повного тиску

Abstract

The subject of this study is the total pressure conservation coefficient. The object of this study is the channel of the subsonic part of a supersonic input device of rectangular and oval shape, equivalent in size. The purpose of this study is to study the shape of the subsonic part of a supersonic external compression input device. To achieve this purpose, the following tasks were solved: modeling the flow in the subsonic part of a supersonic inlet external compression input device of rectangular and oval shape; calculation of the total pressure conservation coefficient in the subsonic part of the rectangular and oval supersonic inlet external compression input device. When studying the shape of the subsonic part of the supersonic inlet external compression device, the method of numerical experiment was used. The studies were conducted at an estimated altitude of 12 km and an estimated Mach number M = 2.5. The influence of the fuselage on the operation of the input device was not considered. To study the influence of the cross-sectional shape of the studied subsonic parts of the inlet device, the coefficient of conservation of total pressure in 7 cross sections along the length of the inlet device was calculated. To obtain the initial data for modeling the flow in a subsonic channel, an analytical calculation of the flow parameters in the supersonic part of the input device was performed. The results of flow modeling showed that the total pressure conservation coefficient of the subsonic part of the studied inlet devices when operating at an altitude of 12 km was 0.982 in the subsonic part of the supersonic inlet device with oval sections and 0.993 in the subsonic part of the supersonic inlet device with rectangular sections. The resulting visualization of streamlines in the studied channels demonstrates the presence of a paired vortex formed in the initial section of the channel with oval cross-sections, which leads to significant losses in total pressure. The scientific novelty and practical significance of this study lie in the fact that new data were obtained regarding the comparison of the total pressure conservation coefficient for equivalent subsonic parts of a supersonic oval and rectangular inlet device. Recommendations on the rational form of the subsonic part of the supersonic inlet external compression device were obtained.