ABSTRACT

An economic combined method of definition is introduced for the vortex wake form and its induced speeds on both lifting propeller disk and directly inside the wake at horizontal flight mode. It includes a definition of induced speeds from nonlinear trailing vortexes with length nv and distorted coils of trail spirals (nv − number of coils), in addition to speeds from the distant trailing vortex computed via impulse theory. Amendments for the induced speeds oriented not only along the y axis but also along x and z are estimated. The computations are performed for the values of characteristics of flight mode μ = 0.31 and 0.0917. The results for diverse lengths of nonlinear trailing vortex compared to induced speeds defined by means of the combined method are provided. An estimation of the influence of orthogonal vortexes on induced speeds is performed.