Aerodynamic Characteristics of Radar Antenna in Stationary and Azimuthal Rotational Motion

To study the effects of aerodynamic loads on the aerodynamic characteristics of stationary and azimuthally rotating antennas, wind tunnel force tests are conducted using solid and porous plate antennas. The variation of aerodynamic coefficient with azimuth angle is obtained when the antenna is stationary and azimuthal rotation, and the results are compared with those from numerical simulations. The variation in the aerodynamic coefficients with respect to the azimuth angle is found to be sinusoidal for both the solid and porous plate antennas rotating in azimuth. Compared with the antenna stationary, quantitative analysis indicates that the rotational motion increases the maximum value and root mean square of the aerodynamic coefficient. For solid plate antenna, |Cx|_max, |Cmy|_max, and |Cmz|_max increase by 41.6%, 15.0%, and 47.3%, respectively; Cx_rms, Cmy_rms, and Cmz_rms increase by 19.0%, 20.0%, and 19.1%, respectively. For porous plate antenna, |Cx|_max, |Cmy|_max, and |Cmz|_max increase by 30.6%, 71.4%, and 40.9%, respectively; Cx_rms, Cmy_rms, and Cmz_rms increase by 22.9%, 50%, and 20%, respectively. The wind tunnel tests verify the feasibility of using numerical simulations to obtain the flow field results. By analyzing the surface pressure coefficient and vortex core track distribution, the effects of azimuthal rotation on the aerodynamic characteristics of the antenna are further clarified.

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Study on the Aerodynamic Characteristics and Galloping Instability of Conductors Covered with Sector-Shaped Ice by a Wind Tunnel Test

International Journal of Structural Stability and Dynamics ◽

10.1142/s0219455420400167 ◽

2020 ◽

Vol 20 (06) ◽

pp. 2040016

Author(s):

Jia-Xiang Li ◽

Jian Sun ◽

Ye Ma ◽

Shu-Hong Wang ◽

Xing Fu

Keyword(s):

Wind Tunnel ◽

Drag Coefficient ◽

Wind Tunnel Test ◽

Aerodynamic Characteristics ◽

Ice Thickness ◽

Shape Parameters ◽

Aerodynamic Coefficient ◽

Wind Tunnel Tests ◽

And Control

Conductors with sector-shaped ice are susceptible to galloping. To prevent and control galloping, it is necessary to study the conductor aerodynamic characteristics. Wind tunnel tests were performed to study the influence of two shape parameters (ice thickness and ice angle) of a conductor with sector-shaped ice on the aerodynamic characteristics considering the roughness of the surface. In addition, the unstable areas for galloping are discussed according to Den Hartog theory and Nigol theory. The results show that with increasing ice thickness, the aerodynamic coefficient curves fluctuate more strongly, and galloping tends to occur; with increasing ice angle, the unstable area becomes larger according to Nigol theory, and the increasing drag coefficient will suppress the unstable areas according to Den Hartog theory. With the increasing two shape parameters, the most affected ranges of the aerodynamic coefficient curves are 150–180∘.

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Numerical Simulations and Wind Tunnel Experiments of Aerodynamic Characteristics on Waverider with Orbiter

The Proceedings of Conference of Kyushu Branch ◽

10.1299/jsmekyushu.2017.70.502 ◽

2017 ◽

Vol 2017.70 (0) ◽

pp. 502

Author(s):

Tomoki UZAKI ◽

Tomoyuki MUTA ◽

Nobuyuki TSUBOI ◽

Yusuke MARU ◽

Kazuhisa FUJITA

Keyword(s):

Wind Tunnel ◽

Numerical Simulations ◽

Aerodynamic Characteristics ◽

Wind Tunnel Experiments

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A research on aerodynamic characteristics of non-pneumatic tire

Mechanics & Industry ◽

10.1051/meca/2021026 ◽

2021 ◽

Vol 22 ◽

pp. 27

Author(s):

Hong Li ◽

Yilun Xu ◽

Chenlong Si ◽

Yong Yang

Keyword(s):

Wind Tunnel ◽

Structural Parameters ◽

Wind Tunnel Test ◽

Aerodynamic Characteristics ◽

Aerodynamic Coefficient ◽

Pneumatic Tire ◽

Simulation Calculation ◽

Calculation Results ◽

Fluent Software ◽

Static Conditions

Application of non-pneumatic tire (NPT) has been increased during the last decade. The aerodynamic characteristics of the wheel with NPT has been studied due to significance on improvement of handling and reduction of fuel consumption. In this paper, first, an original NPT model was simulated by CATIA software, and the influence of NPT structural parameters on aerodynamic characteristics was studied by Fluent software. The simulation calculation results showed that: the reduction of tire width and spoke length, and the increase of spoke thickness can effectively decrease aerodynamic coefficient. Then, the MIRA model was used to study the influence of NPT on aerodynamic characteristics of the whole vehicle under driving conditions. Studies showed that: NPT increased the resistance of the whole vehicle, and 63.1% of the resistance at the wheels was provided by the front wheels. Finally, the wind tunnel test was conducted to study aerodynamic characteristics of the optimized NPT model under static conditions and verify the simulation calculation.

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Numerical Simulation and Wind Tunnel Experiment of the Aerodynamic Characteristics of a Formula Student Racing Car

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.774-776.460 ◽

2013 ◽

Vol 774-776 ◽

pp. 460-464

Author(s):

Guo Xin Wang ◽

Yinuo Hu ◽

Ting Ting Xu ◽

Ze Fei Li ◽

Bo Yang

Keyword(s):

Numerical Simulation ◽

Wind Tunnel ◽

Numerical Simulations ◽

Aerodynamic Characteristics ◽

Wind Tunnel Experiment ◽

Rear Wing ◽

Front Wing ◽

The Difference

This research used CFD softwares to simulate the downforce generated with the airfoil set to different height, and also analyzed the difference on the downforce when the airfoil is set on the racing car. Several pairs of front wing (FW) and rear wing (RW) of different ground clearances were chosen during the wind tunnel experiment and the results were compared with those of the numerical simulations. With the results of the simulations as well as the experiment, an appropriate solution of the ground clearances of the FW and RW for different kinds of race is provided.

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Numerical Simulations of the Wind Tunnel Tests on the Aerodynamic Characteristics of Trains in the Crosswind

Quarterly Report of RTRI ◽

10.2219/rtriqr.59.2_115 ◽

2018 ◽

Vol 59 (2) ◽

pp. 115-120 ◽

Cited By ~ 1

Author(s):

Yuhei NOGUCHI ◽

Koji NAKADE

Keyword(s):

Wind Tunnel ◽

Numerical Simulations ◽

Aerodynamic Characteristics ◽

Wind Tunnel Tests

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Wind Load of Telecom Equipment in Masts – Comparing Numerical Simulations and Wind Tunnel Measurements

2020 26th International Workshop on Thermal Investigations of ICs and Systems (THERMINIC) ◽

10.1109/therminic49743.2020.9420494 ◽

2020 ◽

Author(s):

Tomas W. Muld ◽

Stevin van Wyk ◽

Andreas Ankarbjork

Keyword(s):

Wind Tunnel ◽

Numerical Simulations ◽

Wind Load ◽

Wind Tunnel Measurements

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Galloping Stability and Wind Tunnel Test of Iced Quad Bundled Conductors considering Wake Effect

Discrete Dynamics in Nature and Society ◽

10.1155/2020/8885648 ◽

2020 ◽

Vol 2020 ◽

pp. 1-15

Author(s):

Xiaohui Liu ◽

Ming Zou ◽

Chuan Wu ◽

Mengqi Cai ◽

Guangyun Min ◽

...

Keyword(s):

Wind Tunnel ◽

Transmission Lines ◽

Degrees Of Freedom ◽

Wind Tunnel Test ◽

Aerodynamic Coefficients ◽

Wake Effect ◽

Aerodynamic Coefficient ◽

Set Up ◽

The Stability ◽

Three Degrees Of Freedom

A new quad bundle conductor galloping model considering wake effect is proposed to solve the problem of different aerodynamic coefficients of each subconductor of iced quad bundle conductor. Based on the quasistatic theory, a new 3-DOF (three degrees of freedom) galloping model of iced quad bundle conductors is established, which can accurately reflect the energy transfer and galloping of quad bundle conductor in three directions. After a series of formula derivations, the conductor stability judgment formula is obtained. In the wind tunnel test, according to the actual engineering situation, different variables are set up to accurately simulate the galloping of iced quad bundle conductor under the wind, and the aerodynamic coefficient is obtained. Finally, according to the stability judgment formula of this paper, calculate the critical wind speed of conductor galloping through programming. The dates of wind tunnel test and calculation in this paper can be used in the antigalloping design of transmission lines.

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Investigations on Aerodynamic Loading Limits of Subsonic Compressor Tandem Cascades: Midspan Flow

Volume 1: Advances in Aerodynamics ◽

10.1115/imece2013-64488 ◽

2013 ◽

Cited By ~ 1

Author(s):

Charlotte Hertel ◽

Christoph Bode ◽

Dragan Kožulović ◽

Tim Schneider

Keyword(s):

Mach Number ◽

Wind Tunnel ◽

Numerical Simulations ◽

Pressure Distribution ◽

Large Range ◽

Pressure Rise ◽

Transition Model ◽

Diffusion Factor ◽

Aerodynamic Loading ◽

Tandem Cascades

An optimized subsonic compressor tandem cascade was investigated experimentally and numerically. Since the design aims at incompressible applications, a low inlet Mach number of 0.175 was used. The experiments were carried out at the low speed cascade wind tunnel at the Technische Universität Braunschweig. For the numerical simulations, the CFD-solver TRACE of DLR Cologne was used, together with a curvature corrected k-ω turbulence model and the γ-Reθ transition model. Besides the incidence variation, the aerodynamic loading has also been varied by contracting endwalls. Results are presented and discussed for different inlet angles and endwall contractions: pressure distribution, loss coefficient, turning, pressure rise, AVDR and Mach number. The comparison of experimental and numerical results is always adequate for a large range of incidence. In addition, a comparison is made to an existing high subsonic tandem cascade and conventional cascades. For the latter the Lieblein diffusion factor has been employed as a measure of aerodynamic loading to complete the Lieblein Chart of McGlumphy [1].

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