S 弯喷管喷口内切流动特性数值模拟

In order to study the flow characteristics of the S-shaped nozzle with a inscribed exit, numerical simulations were performed for the S-shaped reference nozzle and the S-shaped nozzle with different inscribed angles of 10^◦, 20^◦, 30^◦, 40^◦, and 45^◦. It is shown that, compared with the S-shaped reference nozzle, the nozzle with a inscribed exit will make the flow parameters change more drastically after the first bend in the nozzle, reduce the maximum Mach number and the wave system strength at the nozzle exit, generate two pairs of flow vortices in the center of the jet to traction the jet, change the structure of the wake jet, and increase the length of the high-speed core region of the jet. With the increase of the inscribed angle, the more obvious phenomenon of the jet axial conversion, the influence of angular vortices on the jet increases. The length of the high-speed core region of the jet first increases and then shortens with the acceleration of the axial transition process. The nozzle thrust performance gradually decreases with the increase of the inscribed angle.