Upstream wind tunnel model mounting: The forgotten method for road vehicle aerodynamics

A new method for supporting ground vehicle wind tunnel models is proposed. The technique employs a centrally mounted sting connecting the front face of the vehicle, adjacent to the floor, to a fixed point further upstream. Experiments were conducted on a 1/24th-scale model, representative of a Heavy Goods Vehicle, at a width-based Reynolds number of 2.3 × 105, with detailed comparisons made to more established support methodologies. Changes to mean drag coefficients, base pressures and wake velocities are all evaluated and assessed from both time-independent and time-dependent perspectives, with a particular focus within the wake region. Results show subtle changes in drag coefficient, together with discrete modifications to the flow-field, dependent on the method adopted. Subtle differences in base pressures and wake formation are also identified, with mounting the model upstream found to demonstrate retention of many of the beneficial effects of other techniques without suffering their deficiencies. Overall, these results identify the upstream mounting methodology as a viable alternative to currently available and more well-established techniques used to facilitate wind tunnel aerodynamic interrogation.

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Design of a Large Scale Vertical Stabilizer Wind Tunnel Model for Active Flow Control Research

Volume 5: 6th International Conference on Micro- and Nanosystems; 17th Design for Manufacturing and the Life Cycle Conference ◽

10.1115/detc2012-70197 ◽

2012 ◽

Author(s):

Glenn Saunders ◽

Edward Whalen ◽

Helen Mooney ◽

Sarah Zaremski

Keyword(s):

Wind Tunnel ◽

Flow Control ◽

Large Scale ◽

Active Flow Control ◽

Scale Model ◽

Tunnel Model ◽

Control Research ◽

Model Geometry ◽

Design Requirements ◽

Active Flow

The design, fabrication and installation of an approximately 1/6 scale model of an aircraft vertical stabilizer for research in Active Flow Control (AFC) is discussed. Highlighted are the unique design requirements of wind tunnel models, the specialized fabrication techniques employed to create them and the required close collaboration between industry, government and three academic institutions. The design of the model involves often competing constraints imposed by structural, instrumentation, aerodynamic, manufacturability and research-agenda considerations as well as cost and schedule. Instrumentation requires hundreds of pressure ports and six-axis force/torque sensing. Aerodynamic considerations necessitate high manufacturing precision, highly-skilled fabrication techniques and careful observance of model geometry throughout the design and fabrication processes. A scale model of a vertical stabilizer for AFC research was successfully designed, fabricated and deployed. The collaboratively designed model satisfies the structural, aerodynamic and research design constraints, and furthers the state of the art in Active Flow Control research.

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Method for Real-Time State Estimation of Structural Modes for an Aeroelastic Wind Tunnel Model

AIAA Scitech 2021 Forum ◽

10.2514/6.2021-1643 ◽

2021 ◽

Author(s):

Jared A. Grauer

Keyword(s):

Wind Tunnel ◽

State Estimation ◽

Real Time ◽

Wind Tunnel Model ◽

Tunnel Model

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Wind Tunnel Experiments on the Effect of Combustion in the Wake Region of Supersonic Projectiles-Test Series III

10.21236/adb018467 ◽

1977 ◽

Author(s):

J. Richard Ward ◽

Frank P. Baltakis ◽

Dennis J. Mancinelli

Keyword(s):

Wind Tunnel ◽

Test Series ◽

Wake Region ◽

Wind Tunnel Experiments

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Investigation of the Time Dependence of Wind-Induced Aeroelastic Response on a Scale Model of a High-Rise Building

Applied Sciences ◽

10.3390/app11083315 ◽

2021 ◽

Vol 11 (8) ◽

pp. 3315

Author(s):

Fabio Rizzo

Keyword(s):

Wind Tunnel ◽

Time Dependence ◽

Wind Tunnel Test ◽

Structural Response ◽

Cumulative Distribution ◽

Scale Model ◽

Acquisition Time ◽

Test Results ◽

High Rise ◽

High Rise Building

Experimental wind tunnel test results are affected by acquisition times because extreme pressure peak statistics depend on the length of acquisition records. This is also true for dynamic tests on aeroelastic models where the structural response of the scale model is affected by aerodynamic damping and by random vortex shedding. This paper investigates the acquisition time dependence of linear transformation through singular value decomposition (SVD) and its correlation with floor accelerometric signals acquired during wind tunnel aeroelastic testing of a scale model high-rise building. Particular attention was given to the variability of eigenvectors, singular values and the correlation coefficient for two wind angles and thirteen different wind velocities. The cumulative distribution function of empirical magnitudes was fitted with numerical cumulative density function (CDF). Kolmogorov–Smirnov test results are also discussed.

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Aerodynamic interference test of quad tilt rotor aircraft in wind tunnel

Proceedings of the Institution of Mechanical Engineers Part G Journal of Aerospace Engineering ◽

10.1177/0954410019852827 ◽

2019 ◽

Vol 233 (15) ◽

pp. 5553-5566 ◽

Cited By ~ 2

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.

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