NACA 5312 in ground effect - Wind tunnel and panel code studies

1997 ◽  
Author(s):  
Christof Hiemcke ◽  
Christof Hiemcke
Keyword(s):  
Wind Tunnel ◽  
Ground Effect ◽  
Code Studies

Aerodynamic interference test of quad tilt rotor aircraft in wind tunnel

2019 ◽  
Vol 233 (15) ◽  
pp. 5553-5566 ◽  
Author(s):  
Kun Chen ◽  
Zhiwei Shi ◽  
Shengxiang Tong ◽  
Yizhang Dong ◽  
Jie Chen
Keyword(s):  
Wind Tunnel ◽  
Reference Value ◽  
Ground Effect ◽  
Open Loop ◽  
Force Balance ◽  
Scale Model ◽  
Operating Condition ◽  
Tilt Rotor ◽  
Interference Test ◽  
Aerodynamic Interference

There is an obvious aerodynamic interference problem that occurs for a quad tilt rotor in near-ground hovering or in the conversion operating condition. This paper presents an aerodynamic interference test of the quad tilt rotor in a wind tunnel. A 1:35 scale model of the quad tilt rotor is used in this test. To substitute for the ground, a moveable platform is designed in a low-speed open-loop wind tunnel to simulate different flight altitudes of the quad tilt rotor in hovering or forward flight. A rod six-component force balance is used to measure the loads on the aircraft, and the flow field below the airframe is captured using particle image velocimetry. The experimental results show that the ground effect is significant when the hover height above the ground is less than the rotor diameter of the quad tilt rotor aircraft, and the maximum upload of the airframe is approximately 12% of the total vertical thrust with the appearance of obvious fountain flow. During the conversion operating condition, the upload of the airframe is reduced compared with that in the hovering state, which is affected by rotor wake and incoming flow. The aerodynamic interference test results of the quad tilt rotor aircraft have important reference value in power system selection, control system design, and carrying capacity improvement with the advantage of ground effect.

Wind Tunnel Testing and Computational Fluid Dynamics Analysis of a Wing-in-Ground Effect Vehicle

2007 ◽  
Author(s):  
Boonseng Soh ◽  
Andrew Low ◽  
Cees Bil ◽  
Brendon Bobbermien
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Wind Tunnel ◽  
Ground Effect ◽  
Wind Tunnel Testing ◽  
Cfd Modelling ◽  
Aerodynamic Analysis ◽  
Computational Fluid Dynamics Analysis ◽  
Wing In Ground Effect ◽  
Tunnel Testing

The Wing-in-Ground Effect Concept Technology Demonstrator (WIGE CTD) project is a joint venture between Advanced Aerosystem Technologies Pty Ltd and RMIT University, aiming to design, validate and build a prototype recreational vehicle to fly two passengers over a distance of 500km at approximately 120km/h. The WIGE vehicle will fly very close to the surface, usually water, taking advantage of ground effect to transport passengers with a greater lift/drag ratio, and thus greater fuel-efficiency than conventional aircraft. Following preliminary design, an aerodynamic analysis of the vehicle was performed using wind tunnel testing and Computational Fluid Dynamics (CFD). This paper describes the methods used for wind tunnel testing and CFD modelling of the WIGE CTD design. Results obtained using the two approaches are compared with the aim of validating the CFD model and the techniques used in both wind tunnel and CFD modelling for use in future analyses. In addition to the aerodynamic analysis, a basic CFD prediction of the maximum hydrodynamic drag experienced during take off was attempted using a simple model of the WIGE vehicle hull. This result is required in order to ensure that the aquatic take off required by WIGE vehicles was possible for the design. Concurrently, the feasibility of using a general-purpose CFD solver like Fluent to analyse hull performance was also evaluated through this aspect of the investigation.

Highlights of the Lockheed Martin F-35 STOVL jet effects programme

2009 ◽  
Vol 113 (1140) ◽  
pp. 119-127 ◽  
Author(s):  
R. Hoggarth ◽  
Richard Mange
Keyword(s):  
Wind Tunnel ◽  
System Development ◽  
Ground Effect ◽  
Wind Tunnels ◽  
Wind Tunnel Model ◽  
Low Speed ◽  
Test Conditions ◽  
Tunnel Model ◽  
Testing Techniques ◽  
Flight Regimes

Abstract This paper presents the highlights of the F-35 STOVL Jet Effects (SJE) test effort during the complete four years of the System Development and Demonstration phase. A new 12%-scale F-35 SJE model was tested in the German-Dutch wind-tunnels Large Low Speed Facility in order to gather STOVL jet-induced Forces and Moments. Ten separate test entries were conducted, covering all STOVL flight regimes from pure hover in ground effect through transition to wing borne flight. This paper will present an overview of this program, including a detailed description of the wind-tunnel model, testing techniques, test conditions, and accomplishments.

Wind Tunnel Test of a Blended Wing Aircraft in Ground Effect With Active Flow Control

2016 ◽  
Author(s):  
Michael Mayo ◽  
Jonathan Carroll ◽  
Nicholas Motahari ◽  
Warren Lee ◽  
Robert Englar
Keyword(s):  
Wind Tunnel ◽  
Active Flow Control ◽  
Wind Tunnel Test ◽  
Ground Effect ◽  
Circulation Control ◽  
Wing Model ◽  
Subsonic Wind Tunnel ◽  
Test Methodology ◽  
Tunnel Floor ◽  
Lift And Drag

This paper describes the test methodology and results for a wind tunnel experiment featuring a blended wing aircraft in ground effect with built-in circulation control. A 82.55cm wingspan blended wing model was tested in a subsonic wind tunnel at velocities ranging from 18m/s – 49m/s and corresponding Reynolds numbers ranging from 130k – 350k. Pitch angle was held constant at 0 degrees and the height above the wind tunnel floor was modified to determine lift and drag modification due to ground effect. At a normalized height (y/bw) of 0.06, ground effect increased lift production by 24% and reduced drag by 22% when compared to a normalized height of 0.5. The addition of the circulation control significantly increased the lift production of the model at a cost of increased drag. At a normalized height of 0.031, the lift production increased by 200% at a blowing coefficient of 0.01, but the drag also increased by 72%, ultimately increasing L/D by 178%. Experimental results also suggest that ground effect and circulation control have a synergistic effect when used simultaneously. The effects of Reynolds number and circulation control slot height are also investigated.

Redesign of an Adjustable Slope Moving Ground Plane Wind Tunnel

2011 ◽  
Author(s):  
Matthew T. Boots ◽  
Meagan L. Hubbell ◽  
Gerald M. Angle ◽  
Emily D. Pertl ◽  
James E. Smith
Keyword(s):  
Wind Tunnel ◽  
Test Section ◽  
Ground Plane ◽  
Ground Effect ◽  
The Body ◽  
Original Design ◽  
Local Pressure ◽  
Maximum Angle ◽  
Close Proximity ◽  
Base Structure

Ground effect is an aerodynamic phenomenon that occurs when moving bodies come in close proximity to the ground. A “cushion” of air is created underneath the moving body which provides additional lift by increasing the local pressure under the body surface. To experimentally test ground effect vehicles, a unique wind tunnel is currently being redesigned and constructed at West Virginia University. This wind tunnel incorporates a rotating belt as the ground plane and a centrifugal fan that generates the air flow through the test section in the same direction as the belt’s rotation. The combination of a rotating belt and airflow is used to mimic ground effect in that it is representative of a body moving through still air in close proximity to the ground. The test section and fan assembly sit on a platform that is connected to a movable base frame. The base and testing platform connect through a pivot point that is capable of being raised upward to a maximum angle of fifty degrees to account for gravitational vector alignment between modeled and real world conditions. When the platform is raised and the belt is spinning, the structure is less stable and has the potential to create errors in force readings due to these oscillations, as well as the potential to tip in extreme wind conditions. Thus, the evaluation of the original design and the subsequent redesign are addressed in this research effort. To stabilize the wind tunnel, additional structural elements have been added downstream of the test section. Two telescoping poles were added to the end of the platform that will connect onto outriggers attached to the base structure. These poles and outriggers will form an A-shape support system when the platform is raised to any degree between zero and fifty. The width of the outriggers was calculated and then modeled in conjunction with the existing base structure. The final design is presented in this paper.

Numerical investigation of the aerodynamic characteristics of a train subjected to different ground conditions

2018 ◽  
Vol 232 (10) ◽  
pp. 2371-2384 ◽  
Author(s):  
Ji-qiang Niu ◽  
Xi-feng Liang ◽  
Dan Zhou ◽  
Yue-ming Wang
Keyword(s):  
Wind Tunnel ◽  
Boundary Layers ◽  
High Speed ◽  
Rapid Development ◽  
Ground Effect ◽  
Aerodynamic Performance ◽  
Detached Eddy Simulation ◽  
Scaled Model ◽  
Ground Conditions ◽  
Ground Condition

Due to the rapid development of high-speed railways and the increasing speed of trains, the aerodynamic phenomenon caused by moving trains could be affected. Therefore, the scaled model test has been widely used to simulate the aerodynamic performance of the stationary train in wind tunnel. However, it is difficult to disregard the influence of the ground effect on the aerodynamic performance of trains. In this study, the delayed detached eddy simulation based on the shear stress transport κ–ω turbulence model is used to investigate the aerodynamic performance of trains on three ground conditions (stationary floor + stationary ballast, stationary ground + stationary ballast, and stationary ballast). The numerical method used in this paper is verified by a wind tunnel test. The way the three ground conditions influence the flow field around the train is also analyzed. The results show that the ground condition affects the thickness of the ballast boundary layers without a train, thickness of the train boundary layers, train drag, distribution of pressure and velocity along the train, and the size of the wake region; however, the ground condition had a little effect on the flow structures around the train tail. These findings can help in designing the wind tunnel experiment.

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