Mathematical simulation of the subsonic flow around the lengthening bodies with the flow separation in the region of ground shear with the use of an equivalent body

Abstract

The procedure of the mathematical simulation of the subsonic flow around the elongated bodies for the flow conditions with the flow breakaway in the environment of the line of ground shear is developed on the base of the concept of binding-inviscid interaction. The subsonic motions of gas with the moderate values of the module of the velocity vector of the incident flow were investigated. Adapted the diagram of flow with the equivalent body, whose flow around of the inviscid flow determined speeds and pressures on the surface being investigated. For the purpose of the reduction of the expenditures of computational power it was proposed not to carry out the complex iterative process of the multilevel refinement of the forms of the nose and tailed sections of the equivalent body. The configuration of the surface of the tail section of the equivalent body it was proposed to assign in the form the totality of sections of sufficiently simple form. The semi-infinite section of tail section downstream departed to infinity, preserving in the cross section the constant value of effective diameter. Transition section connected semi-infinite with the nose section of the equivalent body on the line of flow breakaway. For determining the parameters, which characterize the geometry of the tail section of the equivalent body, were used Horner’s formula for the aerodynamic coefficient of base drag and relationship the theories of distant track.The numerical simulation of the inviscid flow around equivalent body was carried out by the method of single vortices. The results of the mathematical simulation of the flow around axisymmetrical cylindrical bodies with the head part of the ogival form are represented. When, before the ground shear, the additional tapered conical part is present, calculated distribution the pressures were compared with the experimental data. In the case of the absence of the tapered part are represented the dependences, which connect the geometric parameters of the streamlined body and tail section of the equivalent body, and also the distribution of speed and pressure on the surface being investigated.