Computational Study of Aerodynamic Characteristics on Reentry Capsule Aft-body Shape in Transonic Flow

2018 ◽  
Author(s):  
Masayuki Nomura ◽  
Koji Fujita ◽  
Hiroki Nagai
Keyword(s):  
Transonic Flow ◽  
Body Shape ◽  
Computational Study ◽  
Aerodynamic Characteristics

scholarly journals Computational Study Of Curved Underbody Diffusers

2019 ◽  
Vol 128 ◽  
pp. 10002
Author(s):  
Angel Huminic ◽  
Gabriela Huminic
Keyword(s):  
Computational Study ◽  
Aerodynamic Characteristics ◽  
Passenger Car ◽  
Lift And Drag ◽  
Underbody Diffuser ◽  
Ahmed Body

This paper presents new results concerning the aerodynamics of the Ahmed body fitted with a non-flat underbody diffuser. As in previous investigations performed, the angle and the length of the diffuser are the parameters systematically varied within ranges relevant for a hatchback passenger car. Coefficients of lift and drag are compared with the values obtained for the flat underbody diffuser, and the results reveal significant improvements concerning aerodynamic characteristics of body.

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.

The Aerodynamics of Trailing-Edge-Cooled Transonic Turbine Blades: Part 2 — Theoretical and Computational Approach

1997 ◽  
Author(s):  
Mathias Deckers ◽  
John D. Denton
Keyword(s):  
Transonic Flow ◽  
Theoretical Study ◽  
Computational Study ◽  
Control Volume ◽  
Turbine Blades ◽  
Computational Approach ◽  
Trailing Edge ◽  
Time Marching ◽  
Transonic Turbine ◽  
Volume Method

A theoretical and computational study into the aerodynamics of trailing-edge-cooled transonic turbine blades is described in this part of the paper. The theoretical study shows that, for unstaggered blades with coolant ejection, the base pressure and overall loss can be determined exactly by a simple control volume analysis. This theory suggests that a thick, cooled trailing edge with a wide slot can be more efficient than a thin, solid trailing edge. An existing time-marching finite volume method is adapted to calculate the transonic flow with trailing edge coolant ejection on a structured, quasi-orthogonal mesh. Good overall agreement between the present method, inviscid and viscous, and experimental evidence is obtained.

Reentry Capsule Dynamic Instability with Different Aft-body Shape in Transonic Flow

2019 ◽  
Author(s):  
Masayuki Nomura ◽  
Arthur Robbe ◽  
Koji Fujita ◽  
Hiroki Nagai
Keyword(s):  
Transonic Flow ◽  
Body Shape ◽  
Dynamic Instability

An Evaluation of Open Source CFD for Study of Aerodynamics of Vehicle Platooning

2019 ◽  
Author(s):  
T. Farid ◽  
A. Shakeel ◽  
M. Sajid
Keyword(s):  
Open Source ◽  
Aerodynamic Drag ◽  
Computational Study ◽  
Autonomous Vehicle ◽  
Aerodynamic Characteristics ◽  
Safety Hazards ◽  
Automated Highways ◽  
Road Congestion ◽  
Vehicle Platooning ◽  
Vehicle Platoons

Abstract The ever-growing road congestion and safety hazards induced by conventional highways has inspired the development of automated highways which provides four key benefits: fuel economy, environmental protection, road safety and smooth traffic flow. Vehicle platooning is a vital component of automated highways which contributes directly to these four benefits with its sequence of closely spaced leader-follower vehicle configuration by taking advantage of the ‘slip-stream’ effect to minimize the aerodynamic drag. Exploratory studies into platooning parameters, vehicle spacing, speeds and number of vehicles, have proven to be prohibitive expensive both computationally and experimentally due to the complexity of tests and the large number of test cases. In recent years, OpenFOAM® an independently developed, supported and documented open-source toolbox has gained popularity by offering a lower cost alternative to leading commercial CFD products. This paper summarizes the results from a computational study of autonomous vehicle platoons and the capability of OpenFOAM® to substitute leading commercial CFD solutions currently used to support vehicle aerodynamic development. This study investigates the aerodynamic characteristics of a 4-SUV platoon at inter-vehicle distances ranging from 0.25 to 1 SUV length at a constant speed of 23 m/s. Trends of the predicted aerodynamic drag coefficients (Cd) are then compared against experimental data from published literature as well as the results obtained from a leading commercial CFD package.

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).

Application of boundary conditions “actuator disk” in computational study of aerodynamic interference of the engine and airframe of a passenger aircraft

2020 ◽  
Author(s):  
I.V. Voronich ◽  
V.H. Nguyen
Keyword(s):  
Power Plant ◽  
Computational Methods ◽  
Computational Study ◽  
Engine Performance ◽  
Aerodynamic Characteristics ◽  
Actuator Disk ◽  
Air Intake ◽  
Aerodynamic Interference ◽  
Passenger Aircraft ◽  
The Impact

Computational methods for obtaining aerodynamic characteristics of an aircraft are currently a source which supplements the data of aerodynamic experiment. This applies to the improvement of local aerodynamics, as well as the impact of the power plant on the flow around the airframe and aerodynamic characteristics of the aircraft. Despite the development of computational methods and computer technology, the tasks of integrating the power plant impose requirements for the refinement of the computational model, which are not fully implementable within the design cycle. However, simpler models can be potentially improved for situations of moderate aerodynamic interference by taking into account the profiles of variables in the air intake formed when the fan is in the nacelle. The paper considers the application of variants of the boundary condition “actuator disk” in the computational study of the contribution of the working power plant to the aerodynamic characteristics of the configuration. The approach is reliable for solving problems of weak and moderate aerodynamic interference. Engine performance has a weak effect on the overall aerodynamic characteristics at small angles of attack, but the component contributions caused by this factor are noticeable and have a different sign, which indicates the need to analyze this interaction.

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