Armand Drábek

Abstract: In this article different wings are computed by low and high-fidelity methods to compare their aerodynamic characteristics. Thanks to the unusual properties of the wing with the bell-shaped lift distribution, several general geometrical variants of the wings were calculated and their results are presented in this work. Three general wings are assumed and their geometry is defined as rectangular, trapezoidal and elliptical. Airspeed, total lift force, shape of airfoil and root chord are defined, and bending moment is assumed as a surrogate model for wing weight. The goal of optimization is minimization of aerodynamic drag.

Abstract: The procedure, which is used in the design of the air nozzle intended to be used on air curtain, is described in this work. The present work is focused on the isolated flow of one air nozzle, while next work will continue with air nozzles constellation. Nozzle reach in the flow field is monitored with and without tangential flow simulating non-isothermal flow. Several basic shapes of nozzles with the same cross-section are evaluated. After searching the design space of the parametric CAD model simulated in isothermal flow – without tangential flow, the best configuration with the longest range were selected. From this smaller set of nozzles was selected one nozzle with the highest directional stability in non-isothermal flow field. The shape of the nozzle with minimal directional deviation in the non-isothermal flow is subsequently optimized by the adjoint method. This method makes it possible to further reduce the pressure loss in the distribution element by deforming the shape according to the local sensitivity of cost function on shape deformation. The final step of design process is to verify effect of modified nozzle on both isothermal and non-isothermal flow filed.

Abstract: In this paper optimization process of the geometrical design of the wing is described. The goal is to minimize the aerodynamic drag at a requested lift in the cruise regime and thus reduce the fuel consumption. The second goal is to ensure the requested landing regime of the aircraft. Both cases are solved under the wing structural and weight considerations. As a fast design computational tool, a lifting line theory is used. It is moreover supplemented by non-linear aerodynamic airfoil characteristics to provide more accurate results of aerodynamic drag of the wing. These airfoil data were calculated with the CFD and enables to take significant accuracy between low and high-fidelity method which is verified in previous work. The list of requirements is set for aircraft for 40 passengers with a range of 2,500 km at a speed of 438 km/h. As the baseline the L-610 aircraft is selected. Optimized wing geometry in verified in cruise and landing regime/configuration with CFD solver. From the calculation of the weight of the wing and CFD results, the flight performance is calculated for the desired flight mission.

Abstract: The new W wing shape (half wing, with “a”half wingspan and “h” wingtip height) approximates the front seen parabola ideal wing by streight lines: line 1 touches parabola at the axis origin and is 25 % of “a”, line 2 is tangent of parabola at the wingtip and cuts the hotizontal line at 50 % of “a”, and line 3 is tangent to parabola, cuts horizontal line at 25 % of “a” and cuts line 2 at 75 % of “a” and 50 % of “h”. Real W wing approximated very close the ideal parabolic wing. The new W wing gives more lateral and directional stability.

Abstract: The aerodynamic efficiency of the albatross has always fascinated researchers and the designing of drones mimicking the albatross's aerodynamic traits have been a major area of interest for the aerospace industry. This review sheds light on the traits behind an albatross's aerodynamic efficiency such as dynamic soaring, bell shaped lift distribution and provides insights into its hereditary posed encodings and evolutions. The soaring techniques have been introduced and discussed along with the albatross's morphology and structure which is responsible for its efficiency. In addition, the albatross's navigational and foraging strategies are briefly discussed to provide a better understanding of the effects of atmospheric conditions on the albatross's flight characteristics and the limitations.