The work represents the results of experimental research of aerodynamics of three-dimensional turbulent jets flowing from nozzles with rectangle outflow face. The results of measurements of average and pulse flow characteristics of threedimensional jets are given. The data on axis speed and turbulence intensity are given and an attempt to reveal their interrelation is made. The results of experimental data comparison on axis speed attenuation of three-dimensional jets with the data for axis symmetric stream are presented.
The article is devoted to the study of a wall-mounted turbulent jet propagating along rough convex and concave surfaces. Currently, there are no strict analytical calculations of wall-mounted turbulent jets due to the complexity of combining the calculations of the free boundary layer on the outer part of the jets with the boundary layer on the surface of the body streamlined by the jet. The study of the aerodynamics of a jet propagating along a curved surface, both on convex and concave surfaces, makes it possible to approach the theoretical solution of problems of wall-mounted turbulent flow, since the question of flow around a cylindrical surface generalizes a large class of problems of jet flow around a surface of various geometries.
It is shown that the aerodynamics of turbulent jets flowing from rectangular nozzles is significantly influenced not only by the presence or absence of limiting end walls, but also by the development of large-scale coherent vortices formed at the initial section of the jet. It is established that in the case of large-scale vortices formed at the initial section with axes parallel to the free edge of the nozzle, they can either rest against the end walls with their ends, or close on themselves at the end walls, covering the initial section of the jet. It is shown that the initially formed annular vortices covering the initial section of the jet deform as they move away from the nozzle and turn into vortex cords with axes parallel to the direction of the jet. As a rule, the vortex cords are arranged symmetrically relative to the axis and have opposite directions. These vortices are the main cause of the appearance of an uneven velocity and temperature profile along the axis. At the same time, large-scale primary vortices with their ends rest against the end walls and cannot cause the appearance of maxima and minima of the velocity profile along the axis. In this case, the development of the boundary layers at the end walls is similar to the development of the boundary layer of a homogeneous flow in a flat channel.
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