AIRPLANE FRICTION DRAG REDUCTION BY MEANS OF MICROBLOWING THROUGH PERMEABLE WING SURFACE SECTIONS

Abstract

The last 45 years have been characterized by escalation of the problem of energy saving and, accordingly, the search and implementation of various resource-saving technologies in various spheres of human activity and, first of all, in the energy and transport sectors. In particular, this problem became urgent for aviation transport and it is not difficult to assume that in the future this process will only increase. Gradual optimization of power plants and aerodynamic design of aircraft in the process of steady improvement of aircraft characteristics and development of the appropriate technological base led to the fact that the traditional methods of fuel consumption reducing are almost exhausted. Aircraft drag consists of several components: inductive, wave, pressure and frictional. The first three components are studied well enough and methods of their reduction are widely used on airplanes. Nevertheless, friction drag can be effectively reduced by boundary layer control methods. Among them there are wellknown and deeply studied ones but for some reasons they were not applied earlier because of the inability or ineffectiveness of their technological implementation. There are methods that are still awaiting for their detailed studies. Determining the optimal, in terms of the frictional drag reduction and the technological considerations, placement and length of the blowing section (or several sections) along the airplane wing chord are practically unexplored. This set of problems is the subject of authors consideration and research presented in this article. On the basis of An-124 aircraft wing the advantages and phenomena of the influence of micro-blowing through the porous section of streamlined surface have been investigated. Parametric analysis of the effect of blowing speed, location and length of the blowing section along the wing has been performed and the conditions and ratios of the parameters, which provide the best effect for the case of maintaining flow without separation, have been determined.