Plasma/wind tunnel experiment with 1/6 scale model of nose part of F-15

For the purposes of this study, a wind tunnel experiment and a numerical analysis during ebb and high tides were conducted to determine the positive and negative effects of wind flow influenced by a seawall structure on the performance of wind turbines installed along a coastal seawall. The comparison of the wind flow field between a wind tunnel experiment performed with a 1/100 scale model and a computational fluid dynamics (CFD) analysis confirmed that the MP k-turbulence model estimated flow separation on the leeside of the seawall the most accurately. The CFD analysis verified that wind speed-up occurred due to the virtual hill effect caused by the seawall’s windward slope and the recirculation zone of its rear face, which created a positive effect by mitigating wind shear while increasing the mean wind speed in the wind turbine’s rotor plane. In contrast, the turbulence effect of flow separation on the seawall’s leeside was limited to the area below the wind turbine rotor, and had no negative effect. The use of the CFD verified with the comparison with the wind tunnel experiment was extended to the full-scale seawall, and the results of the analysis based on the wind turbine Supervisory Control and Data Acquisition (SCADA) data of a wind farm confirmed that the seawall effect was equivalent to a 1.5% increase in power generation as a result of a mitigation of the wind profile.

Download Full-text

Effects of Inflow Shear on Wake Characteristics of Wind-Turbines over Flat Terrain

Energies ◽

10.3390/en13143745 ◽

2020 ◽

Vol 13 (14) ◽

pp. 3745 ◽

Cited By ~ 1

Author(s):

Takanori Uchida

Keyword(s):

Wind Tunnel ◽

Wind Turbine ◽

Wind Turbines ◽

Turbine Rotor ◽

Wind Tunnel Experiment ◽

Scale Model ◽

Speed Ratio ◽

Flat Terrain ◽

Wind Turbine Rotor ◽

Wake Characteristics

The scope of the present study was to understand the wake characteristics of wind-turbines under various inflow shears. First, in order to verify the prediction accuracy of the in-house large-eddy simulation (LES) solver, called RIAM-COMPACT, based on a Cartesian staggered grid, we conducted a wind-tunnel experiment using a wind-turbine scale model and compared the numerical and experimental results. The total number of grid points in the computational domain was about 235 million. Parallel computation based on a hybrid LES/actuator line (AL) model approach was performed with a new SX-Aurora TSUBASA vector supercomputer. The comparison between wind-tunnel experiment and high-resolution LES results showed that the AL model implemented in the in-house LES solver in this study could accurately reproduce both performances of the wind-turbine scale model and flow characteristics in the wake region. Next, with the LES solver developed in-house, flow past the entire wind-turbine, including the nacelle and the tower, was simulated for a tip-speed ratio (TSR) of 4, the optimal TSR. Three types of inflow shear, N = 4, N = 10, and uniform flow, were set at the inflow boundary. In these calculations, the calculation domain in the streamwise direction was very long, 30.0 D (D being the wind-turbine rotor diameter) from the center of the wind-turbine hub. Long-term integration of t = 0 to 400 R/Uin was performed. Various turbulence statistics were calculated at t = 200 to 400 R/Uin. Here, R is the wind-turbine rotor radius, and Uin is the wind speed at the hub-center height. On the basis of the obtained results, we numerically investigated the effects of inflow shear on the wake characteristics of wind-turbines over a flat terrain. Focusing on the center of the wind-turbine hub, all results showed almost the same behavior regardless of the difference in the three types of inflow shear.

Download Full-text

CFD Wing/Pylon/Finned Store Mutual Interference Wind Tunnel Experiment

10.21236/adb152669 ◽

1991 ◽

Cited By ~ 32

Author(s):

E. R. Heim

Keyword(s):

Wind Tunnel ◽

Mutual Interference ◽

Wind Tunnel Experiment

Download Full-text

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.

Download Full-text

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.

Download Full-text