METHOD OF DISCRETE FEATURES AS PLANNING MEANS IS AERODYNAMIC OUTLINES OF TRANSPORT VEHICLES

Abstract

The main stages of the development of the discrete singularities’ method are described. Modern results on the numerical solution of boundary hypersingular integral equations by the methods of collocations and piecewise constant approximations are given. The modern going near planning of aerodynamic design outline of transport vehicles conditionally can be divided into three stages: engineering approaches are close, design on the basis of methods of discrete singularities, approaches that arе based on integration of complete and the Reynolds-averaged of Navier-Stokes equations. On the first stage various engineering approaches are used for forming of aerodynamic outline, going out a requirement specification and requirements of customer. Close geometrical and aerodynamic descriptions are determined in the first. An aerodynamic outline is formed in the first close. On the second stage it follows to use more difficult models of aerodynamics on the basis of various approaches that is built on the model of ideal liquid. Bearing properties are determined, power and moment characteristics for the corresponding outline of aircraft. The third stage is most difficult and expensive cost. On this stage it follows to use methods and models that are based on equations for turbulent flow. The second stage is in-process considered – as means of the previous planning of aerodynamic arrangement with the use of methods of discrete features. A non-stationary chart in that tearing away is designed from all sharp edge of wing is in-process used. This chart has the most general case of forming of process of flowing around of the bearing system of aircraft. However, complication of physical interpretation of forming of such processes in the conditions of ideal liquid remains problematic. The necessities of practice require expansion and deepening of theoretical approaches for the study of non-stationary. Application of model of ideal liquid for the calculation of the bearing system of a perspective transport vehicle allows to set forth aerodynamic task as task of Neumann for Laplace operator. The calculations of the bearing systems of difficult geometrical plane form are conducted. Dependences of carrying capacity and longitudinal moment are got depending on the corner of attack and distance to the ground clearance. A computational experiment confirmed that a method of discrete vorteces was one of important methods of computational aerodynamics. He is effective means for untiing of a number of aerodynamic tasks.