Computational Study of Reynolds Number and Angle-of-Attack Effects on a 1303 UCAV Configuration with a High-Order Overset-Grid Algorithm

2009 ◽  
Author(s):  
Scott Sherer ◽  
Raymond Gordnier ◽  
Miguel Visbal
Keyword(s):  
Reynolds Number ◽  
Computational Study ◽  
Angle Of Attack ◽  
High Order ◽  
Overset Grid ◽  
Grid Algorithm

scholarly journals Computational Investigation of Aerodynamic Characteristics for Elliptic UAVs’ Wing

2018 ◽  
Vol 6 (3) ◽  
Author(s):  
Amaal Attiah ◽  
Ibrahim Elbadawy ◽  
Osama E. Mahmoud
Keyword(s):  
Reynolds Number ◽  
Computational Study ◽  
Angle Of Attack ◽  
Aerodynamic Characteristics ◽  
Thickness Ratio ◽  
Ansys Fluent ◽  
Rotor Wing ◽  
Drag Ratio ◽  
Lift To Drag Ratio ◽  
Elliptic Airfoil

Unmanned Aerial Vehicles, UAVs, gained an important role in modern military and civilian applications. Developments in UAVs technology improve its performance and maneuverability with acceptable cost. Elliptic airfoil had been widely used in the development of Rotor/Wing subsonic aircraft. The present work aims to investigate the effect of various elliptic airfoil parameters, such as Reynolds number, angle of attack and airfoil thickness, on aerodynamic behavior using two-dimensional computational study. The computational results were validated by experimental results. Angles of attack was evaluated from 0° to 18° in order to analyze aerodynamic characteristics up to stall condition, while Reynolds number was evaluated at values of 1×10⁵, 3×105, 2×106, and 8×106, to cover the range of rotary and fixed wing flight conditions. Thickness ratio was ranged from 5% to 25% to include the UAVs airfoil thicknesses so that choice best thickness gets max lift to drag ratio. In addition, the thicknesses location was evaluated for a range of 30% to 70% to get suitable location gets max left to drag ratio. The ANSYS-Fluent software was used with Spalart-Allmaras turbulence model, and found that the maximum lift to drag ratio which improve the UAV capability in this study is at Re=2×106, angle of attack at 8°, max thickness ratio of (0.1chord) located at (0.3chord).

Computational Study of Taper Effect of a Hydrofoil at Different Reynolds Numbers on the Length of Cavity and Lift and Drag Coefficients

2009 ◽  
Author(s):  
Mohammad J. Izadi ◽  
Mahdi Mirtorabi
Keyword(s):  
Reynolds Number ◽  
High Reynolds Number ◽  
Cavity Length ◽  
Computational Study ◽  
Lift Coefficient ◽  
Angle Of Attack ◽  
Three Dimensional ◽  
Reynolds Numbers ◽  
High Reynolds ◽  
Lift And Drag

In this paper a cavitating flow around a three dimensional tapered hydrofoil in an incompressible fluid is modeled and studied. The variables in this study are the taper ratio, angle of attack and the Reynolds number. The taper ratio changes from 0.2 to 1, the angles of attack varies from −2 to 12 degrees and all these are computed at two Reynolds numbers (Re = 5.791·107 and Re = 1.99·108). The flow is assumed to be unsteady and isothermal. Coefficients of drag and lift and also the cavity length are computed numerically. Comparing the numerical results of five investigated models (five tapered hydrofoils) and the work done by Kermeen experimentally, it can be seen that the tapered hydrofoil in some cases gave better results, reducing the cavity length and improving the lift coefficient. At the low Reynolds number, the length of the cavity is calculated to be small in comparison with the length gained at the high Reynolds number, and therefore the change of the taper and the angles of attack did change the amount of the lift coefficient as much. For high Reynolds number, as the angle of attack increased, the tapering effect became more important and the best lift coefficient and minimum cavity length is obtained at a taper ratio of 0.4 for an averaged angles of attack.

scholarly journals Plunging Airfoil: Reynolds Number and Angle of Attack Effects

Aerospace ◽  
2021 ◽  
Vol 8 (8) ◽  
pp. 216
Author(s):  
Emanuel A. R. Camacho ◽  
Fernando M. S. P. Neves ◽  
André R. R. Silva ◽  
Jorge M. M. Barata
Keyword(s):  
Reynolds Number ◽  
High Performance ◽  
Angle Of Attack ◽  
Systems Design ◽  
Reynolds Numbers ◽  
Navier Stokes ◽  
Low Reynolds Numbers ◽  
Operational Conditions ◽  
Naca0012 Airfoil ◽  
The Mean

Natural flight has consistently been the wellspring of many creative minds, yet recreating the propulsive systems of natural flyers is quite hard and challenging. Regarding propulsive systems design, biomimetics offers a wide variety of solutions that can be applied at low Reynolds numbers, achieving high performance and maneuverability systems. The main goal of the current work is to computationally investigate the thrust-power intricacies while operating at different Reynolds numbers, reduced frequencies, nondimensional amplitudes, and mean angles of attack of the oscillatory motion of a NACA0012 airfoil. Simulations are performed utilizing a RANS (Reynolds Averaged Navier-Stokes) approach for a Reynolds number between 8.5×103 and 3.4×104, reduced frequencies within 1 and 5, and Strouhal numbers from 0.1 to 0.4. The influence of the mean angle-of-attack is also studied in the range of 0∘ to 10∘. The outcomes show ideal operational conditions for the diverse Reynolds numbers, and results regarding thrust-power correlations and the influence of the mean angle-of-attack on the aerodynamic coefficients and the propulsive efficiency are widely explored.

Computational Study of the Risø-B1-18 Airfoil with a Hinged Flap Providing Variable Trailing Edge Geometry

2005 ◽  
Vol 29 (2) ◽  
pp. 89-113 ◽  
Author(s):  
Niels Troldborg
Keyword(s):  
Reynolds Number ◽  
Unsteady Flow ◽  
Computational Study ◽  
Turbine Blades ◽  
Aerodynamic Characteristics ◽  
Flow Conditions ◽  
Wind Turbine Blades ◽  
Trailing Edge ◽  
Edge Geometry ◽  
Fully Developed Turbulent Flow

A comprehensive computational study, in both steady and unsteady flow conditions, has been carried out to investigate the aerodynamic characteristics of the Risø-B1-18 airfoil equipped with variable trailing edge geometry as produced by a hinged flap. The function of such flaps should be to decrease fatigue-inducing oscillations on the blades. The computations were conducted using a 2D incompressible RANS solver with a k-w turbulence model under the assumption of a fully developed turbulent flow. The investigations were conducted at a Reynolds number of Re = 1.6 · 106. Calculations conducted on the baseline airfoil showed excellent agreement with measurements on the same airfoil with the same specified conditions. Furthermore, a more widespread comparison with an advanced potential theory code is presented. The influence of various key parameters, such as flap shape, flap size and oscillating frequencies, was investigated so that an optimum design can be suggested for application with wind turbine blades. It is concluded that a moderately curved flap with flap chord to airfoil curve ratio between 0.05 and 0.10 would be an optimum choice.

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