Search Results

This paper is a preliminary step in the direction of the definition of a radically new wing concept that has been conceived to maximize the lift even at low speeds. It is expected to equip new aerial vehicle concepts that aim to compete against helicopters and tilt rotors. They aim achieving very good performance at very low speed (5 to 30 m/s) by mean of an innovative concept of morphing ducted-fan propelled wing that has been designed to maximize the lift force. This paper presents an effective bibliographic analysis of the problem that is a preliminary necessary step in the direction of the preliminary design of the wing. A preliminary CFD evaluation allows demonstrating that the claimed results are in line with the initial expectations. According to the CFD, results it has been produced a preliminary energetic evaluation of the vehicle in a flying car configuration by EMIPS method.

The current paper presents the numerical study of the downwash flowfield characteristics in a cycloidal rotor at close-ground altitudes. In an aircraft equipped with this kind of thruster, the downwash flow plays significant role in different flight modes. The interaction of this downwash jet with ground in effective altitudes is studied using CFD simulations in OpenFOAM. Several operating conditions such as pitching oscillation angles, rotation speeds and height levels are all considered in this work. The results declare that close-ground operating states affects the performance of cyclorotors. The vertical and horizontal forces of a single blade is also analyzed in a complete cycloid in different operating conditions. A lead and lag in maximum and minimum extremes of force curves of a single blade is obtained while being subjected to different functional conditions.

One of the best airplanes ever realized by the European Aircraft industry was the Dornier Do 28D Skyservant, an extraordinary STOL light utility aircraft with the capability to carry up to 13 passengers. It has been a simple and rugged aircraft capable also of operating under arduous conditions and very easy and simple maintenance. The architecture of this airplane, which has operated actively for more than 20 years, is very interesting analyzing the implementation of a new propulsion system because of the unusual incorporation of two engines, as well as the two main landing gear shock struts of the faired main landing gear attached to short pylons on either side of the forward fuselage. This unconventional design allows an easy implementation of different propulsion units, such as the history of different experimental versions allowed.

The impetus of this study is to investigate the effect of using multi dielectric-barrier-discharge plasma actuator (DBDPA) over the 3D-airfoil surface and improve the performance of it. Two designed DBDPAs are placed at the leading edge and a distance of x/c = 0.3 chord of the NACA 634-021 three dimensional (3D) airfoil. We solved the flow at different chord-based Reynolds numbers and in a wide range of angles of attack (AoA) (12∘ ≤ α ≤ 24∘), using a large eddy simulation (LES) turbulence model, which is implemented under the OpenFOAM package framework. Here, detailed flow mechanism analyses, i.e., three-dimensional vortical structure, separation phenomenon, lift and drag coefficients, variation fluctuations and spanwise flow, are investigated around the airfoil 3D. Massive flow separation and transient aerodynamic loads acting on the airfoil have been significantly suppressed by optimized flow control using the DBDPAs in the airfoil.