Method of plan view formation on the front-line aircraft layout scheme synthesis stage
This article describes a method, which allows to generate the aircraft plan view with a minimum number of iterations (revisions after aerodynamic and weight calculations results). The method is described by the example of the front-line aircraft layout scheme development (synthesis), front-line aircraft model made by the normal balancing scheme with two engines and internal cargo bays. The synthesis is carried out on the basis of pre-defined design parameters, constraints, and solutions, which are set by the designer, based on parametric relations and statistical relationships analysis. Designer need to determine the so-called “Layout Field” on the stage of aircraft layout scheme synthesis. “Layout Field” is a plan view on the aircraft geometric shape formation initial stage. Plan view determines the load-bearing capacity and area chart, which defines aircraft volume and wave component in the aerodynamic drag increase. Work is carried out taking into account the structure and division of tasks in the interconnected units, which sequential study allows to achieve the objectives. The transition to the formation of the plan view implies a preliminary definition of design parameters, boundary conditions and areas chart. Design parameters determination, described in the work, carried out at the selected engine thrust based on the approximation of design parameters statistical dependencies of a number of existing fighter aircraft 3, 4 and 5 generations at a selected level of superiority over the prototypes according to the criteria of energy characteristics and the specific load carrying properties. Thus, to determine such parameters included in the methodology, as an area washed by the surface, the volume of the aircraft, space and lengthening the base of the wing. The initial step is to determine the range of possible design parameter values (area of aircraft surface, aircraft volume, area and lengthening of the base wing), in which the method will be working out (verification) further. With the known range of the basic parameters and criteria, there is a further possibility to define the existence region of the main part of the design parameters. The rest of the plane parameters are determined on the basis of a design layout constraints based on the existence region of these parameters. The presented method of determining rational variants of the airplane geometric shape in the early stages of design allows to pre-drop not implemented vectors of design decisions, which, in turn, will reduce the time and costs of the aircraft view synthesis and improve the quality. The possibility of reducing the number of unnecessary options is realized at this stage, and thereby this will reduce labor and time for further analysis.