Machinery & Energetics

To solve the problems of designing systems that operate in Newtonian medium in the mode of streamlined surfaces, it is necessary to determine the characteristics of the motion of such medium on the streamlined surfaces. This will allow you to calculate the energy loss for the transportation of environments, as well as the power characteristics of the movement of objects in such environments. The paper presents the development of an analytical model of tangential stresses that are created on streamlined surfaces in a dynamic laminar boundary layer. The flow environment is adopted by Newtonian. For the universality of results of modeling of speed over a height of a laminar boundary layer and tangential stresses on a streamlined surface, it is carried out in relative parameters. The ratio of the thickness of the boundary layer y/δ is taken within ≈0…1, the ratio of velocities at the boundary and in the boundary layer is – vx /vo = 0…1, the Mach number under the condition of the laminar boundary layer is - 0,0001…0,1. As a result of the simulation, the velocity distribution over the thickness of the boundary layer and tangential stresses are obtained. The nature of the change in tangential stresses along the thickness of the boundary layer from ≈0 to 20·10-21 is linear and depends on the Mach number. The tangential stresses change directly on the streamlined surface from 704.4 EPa to 704.4 PPa at Mach numbers from - 0,0001…0,1. Developed analytical dependences of velocity and tangential stresses allow modeling the dynamic characteristics over the height of the laminar boundary layer on the streamlined surface for Newtonian medium.

experimental research, change in departure, the combination of movements, loader crane, dynamic loads, load vibrations