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Numerical and analytical modeling of the propulsive wing and fuselage of an air taxi

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The problem of creating propulsive airfoils is considered. Such airfoils have a slit through which the boundary layer is sucked out. Located just behind this gap, a specially profiled section of the airfoil creates a propulsive thrust. The thrust is created due to an abrupt change in the pressure profile on the slit through which the boundary layer is sucked. In the last 15–20 years, the concept of a so-called propulsive wing with reduced or zero aerodynamic drag due to the suction of the boundary layer from its upper surface has been actively studied in the world. Such a wing makes it possible to reduce the aerodynamic drag of the aircraft by several times due to boundary layer laminarization and minimizing the velocity defect associated with viscous friction in the boundary layer, in the wake of the aircraft. The paper proposes a method for numerical modeling of airfoils for a propulsive wing constructed by solving the inverse problem of aerodynamics. The designed airfoils have a maximum construction height, an optimal combination of the lifting force coefficient Cl and the thrust coefficient CT, created by air suction from the wing surface. The developed technique correctly predicts the point of the laminar-turbulent transition, since the characteristics of the airfoils directly depend on the length of the laminar section. The layout of an aircraft built according to the scheme of a propulsive flying wing of ultra-small aspect ratio using the developed airfoils has been studied. The design of aerodynamic profiles was carried out by solving the inverse problem of aerodynamics with subsequent refinement of geometry using global optimization algorithms. Calculations were carried out using the Langtry−Menter turbulence γ-ReΘ Transition Shear Stress Transport model, in which there are relations for the intermittency criterion, makes it possible to simulate a laminar-turbulent transition. Calculations have shown that the developed airfoils make it possible to create an aircraft airframe with a maximum lift coefficient Clmax which exceeds the Clmax of a mechanized wing with a flap released during takeoff and landing. In horizontal flight, the Cl is three times larger than that of a typical wing. The wing with the developed profiles has a high propulsive efficiency due to the proximity of pressure and velocity in the thrust section of the airfoils and external flow. At the same time, the thrust surface of the propulsive wing exceeds the nozzle area or the total coverage of aircraft propellers by several times. The developed airfoils and integrated aerodynamic layout of the aircraft are well combined with the principles of building a distributed power plant, and allow you to combine immunity to increased atmospheric turbulence during vertical takeoff and landing with economical horizontal flight. Airfoils have an important advantage over traditional wing mechanization because they have no moving parts, and the increase or decrease in lift is regulated by changing the flow rate of the sucked air.

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