Active Flow Control over the Car

2011 ◽  
Vol 110-116 ◽  
pp. 2521-2528
Author(s):  
Deepesh Kumar Singh ◽  
Gautam Bandyopadhyay
Keyword(s):  
Flow Control ◽  
Aerodynamic Drag ◽  
Active Flow Control ◽  
Lift Coefficient ◽  
Boundary Layer Suction ◽  
Car Model ◽  
The Standard Model ◽  
Drag And Lift ◽  
Drag And Lift Coefficient ◽  
Active Flow

Active flow control methods are used to reduce the aerodynamic drag over a car model. Method of Boundary layer suction at the top rear and air injection at the back of the car are used as the active flow control tools to suppress the aerodynamic drag. The computational results obtained using the standard model for the car model are verified first against the practical results obtained by wind tunnel experimentation so as to obtain the range of turbulence. Then a parametric study on the effect of the drag and lift coefficient of the car with respect to the parameters governing the active flow control is done. The drag coefficient is reduced by 20.25% using this strategy with 19.4% increase in the lift coefficient.

scholarly journals Model free active flow control of a simplified car model

2019 ◽  
Vol 52 (5) ◽  
pp. 115-120
Author(s):  
B. Plumejeau ◽  
S. Delprat ◽  
L. Keirsbulck
Keyword(s):  
Flow Control ◽  
Active Flow Control ◽  
Car Model ◽  
Model Free ◽  
Active Flow

scholarly journals Numerical study on the steady suction active flow control of hydrofoil in the profile of the blended-wing-body underwater glider

2021 ◽  
Vol 39 (4) ◽  
pp. 801-809
Author(s):  
Xiaoxu Du ◽  
Lianying Zhang
Keyword(s):  
Flow Control ◽  
Numerical Study ◽  
Active Flow Control ◽  
Lift Coefficient ◽  
Leading Edge ◽  
Hydrodynamic Performance ◽  
Flow State ◽  
Underwater Glider ◽  
Blended Wing Body ◽  
Active Flow

The hydrodynamic performance of the blended-wing-body underwater glider can be improved by opening a hole on the surface and applying the steady suction active flow control. In order to explore the influence law and mechanism of the steady suction active flow control on the lift and drag performance of the hydrofoil, which is the profile of the blended-wing-body underwater glider, based on the computational fluid dynamics (CFD) method and SST k-ω turbulence model, the steady suction active flow control of hydrofoil under different conditions is studied, which include three suction factors: suction angle, suction position and suction ratio, as well as three different flow states: no stall, critical stall and over stall. Then the influence mechanism in over stall flow state is further analyzed. The results show that the flow separation state of NACA0015 hydrofoil can be effectively restrained and the flow field distribution around it can be improved by a reasonable steady suction, so as to the lift-drag performance of NACA0015 hydrofoil is improved. The effect of increasing lift and reducing drag of steady suction is best at 90° suction angle and symmetrical about 90° suction angle, and it is better when the steady suction position is closer to the leading edge of the hydrofoil. In addition, with the increase of the suction ratio, the influence of steady suction on the lift coefficient and drag coefficient of hydrofoil is greater.

Active Flow Control of Flapping Airfoil Using Openfoam

2019 ◽  
Vol 36 (3) ◽  
pp. 361-372
Author(s):  
Vedulla Manoj Kumar ◽  
Chin-Cheng Wang
Keyword(s):  
Flow Control ◽  
Active Flow Control ◽  
Lift Coefficient ◽  
Unsteady Motion ◽  
Plasma Actuators ◽  
Beneficial Effects ◽  
Plasma Actuation ◽  
Reduced Frequency ◽  
Flapping Airfoil ◽  
Active Flow

ABSTRACTThe concept of the fixed wing Micro Air Vehicles (MAVs) has received increasing interest over the past few decades, with the principal aim of carrying out the surveillance missions. The design of the flapping wing MAVs still is in infancy stage. On the other hand, there has been increasing interest over the flow control using plasma actuators in worldwide. The aim of this research is to study the flow control of a flapping airfoil with and without plasma actuation in OpenFOAM. The OpenFOAM CFD platform has been used to develop our own plasma solver. For the plasma induced turbulence in the flow regime, k-ε turbulence model was adopted to address the interaction between plasma and fluid flows. For the plasma-fluid interaction, we use reduced-order modelling to solve the plasma induced electric force. A two dimensional NACA0012 flapping airfoil without plasma actuation study has been benchmarked with previous published literature. We have not only focused on the active flow control but also analyzed the important parameter reduced frequency at different values, those are 0.1, 0.05 and 0.025. Reduced frequency (κ) is very important parameter of an airfoil in the unsteady motion. Our major contribution is testing the several reduced frequencies with the plasma actuation. The positive and beneficial effects of the plasma actuator for all cases have been observed. From the observed results, the flapping with plasma actuation at reduced frequency of 0.1 showed the 14.285 percent lift improvement and the 16.19 percent drag reduction than the flapping without plasma actuation at the respective dynamic stall angles. The maximum lift coefficient is increased with the increase in reduced frequency. In overall, plasma actuators are effective in the flow control of a flapping airfoil. In future, the combination of the flapping with plasma actuators will be a promising application to boast the maneuverability of MAVs.

Active flow control on a 1:4 car model

2014 ◽  
Vol 55 (5) ◽  
Author(s):  
Till Heinemann ◽  
Matthias Springer ◽  
Hermann Lienhart ◽  
Stefan Kniesburges ◽  
Carsten Othmer ◽  
...  
Keyword(s):  
Flow Control ◽  
Active Flow Control ◽  
Car Model ◽  
Active Flow

scholarly journals Active Flow Control in a Radial Vaned Diffuser for Surge Margin Improvement: A Multislot Suction Strategy

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Aurélien Marsan ◽  
Isabelle Trébinjac ◽  
Stéphane Moreau ◽  
Sylvain Coste
Keyword(s):  
Boundary Layer ◽  
Flow Control ◽  
Active Flow Control ◽  
Control Technique ◽  
Navier Stokes ◽  
Compressor Stage ◽  
Vaned Diffuser ◽  
Boundary Layer Suction ◽  
Surge Margin ◽  
Active Flow

This work is the final step of a research project that aims at evaluating the possibility of delaying the surge of a centrifugal compressor stage using a boundary-layer suction technique. It is based on Reynolds-Averaged Navier-Stokes numerical simulations. Boundary-layer suction is applied within the radial vaned diffuser. Previous work has shown the necessity to take into account the unsteady behavior of the flow when designing the active flow control technique. In this paper, a multislot strategy is designed according to the characteristics of the unsteady pressure field. Its implementation results in a significant increase of the stable operating range predicted by the unsteady RANS numerical model. A hub-corner separation still exists further downstream in the diffuser passage but does not compromise the stability of the compressor stage.

Multidisciplinary design optimisation of a fully electric regional aircraft wing with active flow control technology

2021 ◽  
pp. 1-25
Author(s):  
V. Mosca ◽  
S. Karpuk ◽  
A. Sudhi ◽  
C. Badrya ◽  
A. Elham
Keyword(s):  
Boundary Layer ◽  
Flow Control ◽  
Electric Propulsion ◽  
Active Flow Control ◽  
Multidisciplinary Design ◽  
Aircraft Wing ◽  
Design Optimisation ◽  
Boundary Layer Suction ◽  
Active Flow ◽  
Multidisciplinary Design Optimisation

Abstract The German research Cluster of Excellence SE2A (Sustainable and Energy Efficient Aviation) is investigating different technologies to be implemented in the following decades, to achieve more efficient air transportation. This paper studies the Hybrid Laminar Flow Control (HLFC) using boundary layer suction for drag reduction, combined with other technologies for load and structural weight reduction and a novel full-electric propulsion system. A multidisciplinary design optimisation framework is presented, enabling physics-based analysis and optimisation of a fully electric aircraft wing equipped with HLFC technologies and load alleviation, and new structures and materials. The main focus is on simulation and optimisation of the boundary layer suction and its influence on wing design and optimisation. A quasi three-dimensional aerodynamic analysis is used for drag estimation of the wing. The tool executes the aerofoil analysis using XFOILSUC, which provides accurate drag estimation through boundary layer suction. The optimisation is based on a genetic algorithm for maximum take-off weight (MTOW) minimisation. The optimisation results show that the active flow control applied on the optimised geometry results in more than 45% reduction in aircraft drag coefficient, compared to the same geometry without HLFC technology. The power absorbed for the HLFC suction system implies a battery mass variation lower than 2%, considering the designed range as top-level requirement (TLR).

LES of Active Separation Control on Bluff Bodies by Steady Blowing

2010 ◽  
Author(s):  
Sa´ndor Eichinger ◽  
Frank Thiele ◽  
Erik Wassen
Keyword(s):  
Flow Control ◽  
Aerodynamic Drag ◽  
Active Flow Control ◽  
Rear Surface ◽  
Base Flow ◽  
Back Surface ◽  
Bluff Bodies ◽  
Control Approach ◽  
Vertical Extension ◽  
Active Flow

An active flow control approach was investigated in order to reduce the aerodynamic drag of a generic square-backed vehicle. The investigations were carried out at a Reynolds number of ReL = 500,000. Large Eddy Simulations were performed which are suitable for time dependent flows around vehicles with large coherent structures. After the base flow simulations active flow control was applied in order to achieve drag reduction using steady blowing through small slits near the edges of the rear surface. The blowing velocity was equal to the inflow velocity (vblow = U0), and the blowing angle was changed from θ = 0° to θ = 60°. It is shown that these control techniques can achieve a maximum drag decrease for the θ = 45° control version of around 12%. Additionally the effect of moving floor was studied and comparison was made for the baseline and for the 45° flow control variant. It was found that the stagnation point on the rear surface moves upwards, and the vertical extension of the wake section reduces, so the evolving pressure level on the back surface increases. Finally a study of the blowing velocity was performed, changing vblow = 0.25U0 until vblow = 2.25U0 at θ = 45° blowing angle. An efficiency optimum was found around vblow = 1.25U0.

Reducing Energy Consumption of Ground Vehicles by Active Flow Control

2010 ◽  
Author(s):  
Miles Bellman ◽  
Ramesh Agarwal ◽  
Jonathan Naber ◽  
Lee Chusak
Keyword(s):  
Experimental Data ◽  
Flow Control ◽  
Numerical Simulations ◽  
Fuel Consumption ◽  
Aerodynamic Drag ◽  
Active Flow Control ◽  
Ground Vehicles ◽  
Ground Vehicle ◽  
Jet Actuators ◽  
Active Flow

In U.S, the ground vehicles consume about 77% of all (domestic and imported) petroleum; 34% is consumed by automobiles, 25% by light trucks and 18% by large heavy duty trucks and trailers. It has been estimated that 1% increase in fuel economy can save 245 million gallons of fuel/year. Additionally, the fuel consumption by ground vehicles accounts for over 30% of CO2 and other greenhouse gas (GHG) emissions. Moreover, most of the usable energy from the engine goes into overcoming the aerodynamic drag (53%) and rolling resistance (32%); only 9% is required for auxiliary equipment and 6% is used by the drive-train. 15% reduction in aerodynamic drag at highway speed of 55mph can result in about 5–7% in fuel saving. The goal of this paper is to demonstrate by numerical simulations that the active flow control (AFC) technology can be easily deployed /retrofitted to reduce the aerodynamic drag of ground vehicles by 15–20% at highway speed. For AFC, we employ a few oscillatory jet actuators (also known as synthetic jet actuators) at the rear face of the ground vehicle. These devices are easy to incorporate into the existing vehicles with very modest cost. The cost may come down significantly for a large volume — in hundreds of millions, especially for ground vehicles. Numerical simulations are performed using the Unsteady Reynolds-Averaged Navier-Stokes (URANS) equations on solution adaptive structured grids in conjunction with a two-equation realizable k-ε turbulence model. The commercially available grid generator “GAMBIT” and the CFD solver “FLUENT” are employed in the simulations. Three generic ground vehicle configurations are considered in the simulations; the experimental data has been available for these configurations without and with AFC. The numerical simulations are in good agreement with the experimental data. These studies clearly demonstrate that the AFC techniques can be effectively employed to achieve significant reduction (10–15%) in aerodynamic drag of ground vehicles thereby reducing the fuel consumption by 5–7%.

Sign in / Sign up

Export Citation Format

Share Document