scholarly journals Conceptual Design of a Novel Unmanned Ground Effect Vehicle (UGEV) and Flow Control Integration Study

Drones ◽  
2022 ◽  
Vol 6 (1) ◽  
pp. 25
Author(s):  
Charalampos Papadopoulos ◽  
Dimitrios Mitridis ◽  
Kyros Yakinthos
Keyword(s):  
Flow Control ◽  
Conceptual Design ◽  
Active Flow Control ◽  
Ground Effect ◽  
Passive Flow Control ◽  
Control Techniques ◽  
Passive Flow ◽  
Conceptual Design Phase ◽  
Wide Range ◽  
Active Flow

In this study, the conceptual design of an unmanned ground effect vehicle (UGEV), based on in-house analytical tools and CFD calculations, followed by flow control studies, is presented. Ground effect vehicles can operate, in a more efficient way, over calm closed seas, taking advantage of the aerodynamic interaction between the ground and the vehicle. The proposed UGEV features a useful payload capacity of 300 kg and a maximum range of 300 km cruising at 100 kt. Regarding the aerodynamic layout, a platform which combines the basic geometry characteristics of the blended wing body (BWB), and box wing (BXW) configurations is introduced. This hybrid layout aims to incorporate the most promising features from both configurations, while it enables the UGEV to operate under adverse flight conditions of the atmospheric boundary layer of the earth. In order to enhance the performance characteristics of the platform, both passive and active flow control techniques are studied and incorporated into the conceptual design phase of the vehicle. For the passive flow control techniques, the adaptation of tubercles and wing fences is evaluated. Regarding the active flow control techniques, a wide range of morphing technologies is investigated based on performance and integration criteria. Finally, stability studies are conducted for the proposed platform.

Active and Passive Flow Control of an Incompressible Axisymmetric Jet

2008 ◽  
Author(s):  
Nagendra Karthik Depuru Mohan ◽  
David Greenblatt ◽  
Christian Navid Nayeri ◽  
Christian Oliver Paschereit ◽  
Panchapakesan Nagangudy Ramamurthi
Keyword(s):  
Flow Control ◽  
Active Flow Control ◽  
Central Portion ◽  
Jet Stream ◽  
Streamwise Vortices ◽  
Passive Flow Control ◽  
Axisymmetric Jet ◽  
Passive Flow ◽  
Negative Pressures ◽  
Active Flow

An experimental investigation was carried out to compare active and passive flow control of an incompressible axisymmetric jet. For active flow control, the lip of the circular jet was equipped with a single small flap deflected away from the jet stream at an angle of 30°. The flap incorporated a flow control slot through which steady suction and oscillatory suction were implemented. For passive flow control, the lip of the circular jet was equipped with a single small triangular tab deflected into the jet stream at an angle of 30°. Both the flap and triangular tab chord lengths were one sixth of the jet diameter. The momentum of jet increased in the case of active flow control by entraining ambient fluid, whereas momentum decreased in the case of passive flow control. The effect of steady suction saturated for volumetric suction coefficient values greater than approximately 0.82%. The strength of the streamwise vortices generated by active flow control flaps were greater than those generated by the passive triangular tab. Steady suction produced positive pressures just downstream of the flow control slot in the central portion of the flap and negative pressures at the flap edges. Oscillatory suction was highly dependent on dimensionless frequency (F+) based on flap-length; the pressures on the central portion of the flap increased for F+≤0.11 and then decreased for greater F+; finally attaining negative pressures at F+ = 0.44. The increase in jet momentum, combined with the generation of strong streamwise vortices makes a strong case for improvements in propulsion efficiency and jet noise reduction.

Control of Centrifugal Instability in Vortex-Surface Interaction

2015 ◽  
Author(s):  
Vaibhav Kumar ◽  
Nandeesh Hiremath ◽  
Dhwanil Shukla ◽  
Nikolaus Thorrell ◽  
Narayanan Komerath
Keyword(s):  
Flow Control ◽  
Delta Wing ◽  
Active Flow Control ◽  
Angle Of Attack ◽  
Surface Flow ◽  
Near Surface ◽  
Passive Flow Control ◽  
Passive Flow ◽  
Centrifugal Instability ◽  
Active Flow

The interaction of a rotating conical flow with a solid surface generates a centrifugal instability. This occurs in the flow over the wings of certain types of aircraft at high angles of attack. Efforts at our laboratory have detected such structures using near-surface flow diagnostics, and shown that they can be effectively alleviated using passive flow control near the surface. Their alleviation removes the narrowband spectral peak at the nominal location of vertical fins on these aircraft. This paper explores the substitution of active flow control techniques that remain conformal to the surface and are only powered during high angle of attack operation. The occurrence of the phenomenon and its 15-dB alleviation with geometric fences are shown on a rounded-edge 42-degree swept, cropped delta wing at 25 degrees angle of attack. The feasibility and power requirements for the plasma actuator are estimated in this paper. The generation of counter-rotating vortices using a double dielectric barrier discharge actuator is demonstrated.

scholarly journals Drag reduction by combination of flow control using inlet disturbance body and plasma actuator on cylinder model

2019 ◽  
Vol 13 (1) ◽  
pp. 4503-4511
Author(s):  
Budiarso . ◽  
Harinaldi . ◽  
E. A. Kosasih ◽  
R. F. Karim ◽  
J. Julian
Keyword(s):  
Reynolds Number ◽  
Flow Control ◽  
Active Flow Control ◽  
Plasma Actuators ◽  
Test Model ◽  
Passive Flow Control ◽  
Passive Flow ◽  
Reduction Coefficient ◽  
Flow Past A Cylinder ◽  
Active Flow

Flow past a cylinder is one of the things that is very applicable in everyday life. But behind those facts, there is a problem in it namely the drag force which is adverse and needs to be reduced. This research was conducted to find solutions to reduce drag by using a mix of passive flow control of inlet disturbance body and active flow control from plasma actuators. This research uses a test model in the form of a cylinder of a diameter of 120 mm with Reynolds Number 15000, 41000, 62000 and was expected to reduce drag after a given combination of flow control. From the results shown, either inlet disturbance of body and plasma actuators as well as a combination of both the flow of control is capable of performing the reduction coefficient of drag up to 70,22% on a variation of the Reynolds Number 62000.

scholarly journals Experimental and numerical results of active flow control on a highly loaded stator cascade

2011 ◽  
Vol 225 (7) ◽  
pp. 907-918 ◽  
Author(s):  
M Hecklau ◽  
C Gmelin ◽  
W Nitsche ◽  
F Thiele ◽  
A Huppertz ◽  
...  
Keyword(s):  
Flow Control ◽  
Active Flow Control ◽  
Numerical Results ◽  
Pressure Probe ◽  
Compressor Cascade ◽  
Time Resolved ◽  
Inlet Velocity ◽  
Wide Range ◽  
Active Flow ◽  
Highly Loaded

This article presents experimental and numerical results for a compressor cascade with active flow control. Steady and pulsed blowing has been used to control the secondary flow and separation characteristics of a highly loaded controlled diffusion airfoil. Investigations were performed at the design incidence for blowing ratios from approximately 0.7 to 3.0 (jet-to-inlet velocity) and a Reynolds number of 840 000 (based on axial chord and inlet velocity). Detailed flow field data were collected using a five-hole pressure probe, pressure taps on the blade surfaces, and time-resolved Particle Image Velocimetry. Unsteady Reynolds-averaged Navier–Stokes simulations were performed for a wide range of flow control parameters. The experimental and numerical results are used to understand the interaction between the jet and the passage flow. The benefit of the flow control on the cascade performance is weighted against the costs of the actuation by introducing an efficiency which takes the presence of the jets into account.

Helicopter Fuselage Model Drag Reduction by Active Flow Control Systems

2019 ◽  
Vol 64 (2) ◽  
pp. 1-15 ◽  
Author(s):  
Fabrizio De Gregorio
Keyword(s):  
Experimental Investigation ◽  
Flow Control ◽  
Control Systems ◽  
Flow Separation ◽  
Laboratory Tests ◽  
Active Flow Control ◽  
Aerodynamic Characteristics ◽  
Pulsed Jets ◽  
Wide Range ◽  
Active Flow

A comprehensive experimental investigation of a helicopter blunt fuselage model was carried out to evaluate the effectiveness of active flow control (AFC) systems in reducing parasite fuselage drag. The main objective was to demonstrate the capability of different active technologies to decrease fuselage drag by alleviating the flow separation in the loading ramp region of large transport helicopters. The work was performed on a simplified blunt fuselage at model scale. Two different flow control actuators were considered for evaluation: steady blowing and unsteady blowing (i. e., pulsed jets). Laboratory tests of each individual actuator were performed to assess their performance and properties. The fuselage model was investigated with and without the AFC systems located along the loading ramp edges. Significant drag reductions were achieved for a wide range of fuselage angles of attack and sideslip angles without negatively affecting other aerodynamic characteristics.

Partial Cavitation as Drag Reduction Technique and Problem of Active Flow Control

2003 ◽  
Vol 40 (03) ◽  
pp. 181-188
Author(s):  
Eduard Amromin ◽  
Igor Mizine
Keyword(s):  
Drag Reduction ◽  
Flow Control ◽  
Active Flow Control ◽  
Total Drag ◽  
Reduction Techniques ◽  
Partial Cavitation ◽  
Wide Range ◽  
Hull Design ◽  
Successful Employment ◽  
Active Flow

Partial cavitation can substantially reduce the ship total drag in a wide range of her speed. Vented partial cavitation manifested certain advantages in comparison with other drag reduction techniques. Its successful employment, however, requires both a special hull design and development of an active flow control system. Such a system will stabilize the cavity under perturbations of incoming flow in seas. The paper includes an analysis of achievements in drag reduction, description of design fundamentals of ships with cavitating hulls/elements, and suggestions on application of ship drag reduction by cavitation.

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