The Numerical Simulation of Iced Conductor and Research of Influencing Factors

2015 ◽  
Vol 734 ◽  
pp. 748-752
Author(s):  
Le Gao ◽  
Ji Cai Hu
Keyword(s):  
Numerical Simulation ◽  
Wind Tunnel ◽  
Influencing Factors ◽  
Turbulence Intensity ◽  
Simulation Method ◽  
Aerodynamic Characteristics ◽  
Key Factors ◽  
Wind Tunnel Tests ◽  
Aerodynamic Parameters ◽  
Micro Topography

In order to study the influence of some key factors such as the turbulence intensity related to micro topography and the diameter of conductor to the aerodynamic characteristics of iced conductor , the model is built based on the characteristic of iced conductor with crescent type ,to simulate the aerodynamic parameters for it and compare with the wind tunnel tests .The results show that we can make supplement reference to the wind tunnel tests through the numerical simulation method. Besides , we adjust the model and make research for the influence of diameter of conductor. The aerodynamic parameters we get can provide some reference to the research of galloping conductor.

The Aerodynamic Analysis for Iced Four Bundled Transmission Lines with Typical Crescent

2014 ◽  
Vol 8 (1) ◽  
pp. 84-89 ◽  
Author(s):  
Liu Yuejun ◽  
Tang Ai P. ◽  
Liu Ke T. ◽  
Tu Jie W.
Keyword(s):  
Numerical Simulation ◽  
Wind Tunnel ◽  
Transmission Lines ◽  
Angle Of Attack ◽  
Wind Tunnel Test ◽  
Simulation Method ◽  
Single Wire ◽  
Wind Tunnel Tests ◽  
Absolute Value ◽  
Aerodynamic Test

Despite the fact that the wind tunnel tests have been carried out on iced transmission lines subjected to wind load, it is not practical to do wind tunnel tests due to its high cost. This paper describes a detailed numerical simulation method that can be used to instead of wind tunnel tests. Based on the galloping mechanism of iced transmission lines, the aerodynamic test was simulated with the typical crescent super-large thickness iced four bundled conductors. One of the results highlighted in this study is that the wind angle of attack had significant influence on the aerodynamics of iced conductors. The Den-Hartog and O.Nigol coefficient were calculated to determine galloping of iced transmission lines, comparing with the reference of wind tunnel test in the Zhejiang university, the range of the wind angle of attack to the bundled conductor which can lead to gallop is larger than single wire, but the absolute value of amplitude is less than the single conductor, split conductor is more likely to gallop than single conductor.

Numerical Simulation Study on the Key Influencing Factors of Water-Invasion Performance for the Gas Wells with Bottom-Water

2014 ◽  
Vol 884-885 ◽  
pp. 104-107
Author(s):  
Zhi Jun Li ◽  
Ji Qiang Li ◽  
Wen De Yan
Keyword(s):  
Numerical Simulation ◽  
Influencing Factors ◽  
Bottom Water ◽  
Simulation Method ◽  
Gas Production ◽  
Production Performance ◽  
Gas Wells ◽  
Two Phase ◽  
Gas Well ◽  
Water Gas

For the water-sweeping gas reservoir, especially when the water-body is active, water invasion can play positive roles in maintaining formation pressure and keeping the gas well production. But when the water-cone break through and towards the well bottom, suffers from the influencing of gas-water two phase flows, permeability of gas phase decrease sharply and will have a serious impact on the production performance of the gas well. Moreover, the time when the water-cone breakthrough will directly affect the final recovery of the gas wells, therefore, the numerical simulation method is used to conduct the research on the key influencing factors of water-invasion performance for the gas wells with bottom-water, which is the basis of the mechanical model for the typical gas wells with bottom-water. It indicate that as followings: (1) the key influencing factors of water-invasion performance for the gas wells with bottom-water are those, such as the open degree of the gas beds, well gas production and the amount of Kv/Kh value; and (2) the barrier will be in charge of great significance on the water-controlling for the bottom water gas wells, and its radius is the key factor to affect water-invasion performance for the bottom water gas wells where the barriers exist nearby.

scholarly journals Planetary Atmosphere Wind Tunnel Tests on Aerodynamic Characteristics of a Mars Airplane Scale Model

2014 ◽  
Vol 12 (ists29) ◽  
pp. Pk_7-Pk_12 ◽  
Author(s):  
Masayuki ANYOJI ◽  
Masato OKAMOTO ◽  
Hidenori HIDAKA ◽  
Taku NONOMURA ◽  
Akira OYAMA ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Aerodynamic Characteristics ◽  
Planetary Atmosphere ◽  
Scale Model ◽  
Wind Tunnel Tests

Simulation Method for 3-D Wind Field over Complex Terrain with Asymmetrical Mountains

2013 ◽  
Vol 444-445 ◽  
pp. 549-554
Author(s):  
Huan Ran Hu ◽  
Guan Xin Hong
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Turbulence Intensity ◽  
Potential Flow ◽  
Wind Field ◽  
Complex Terrain ◽  
Simulation Method ◽  
Engineering Practice ◽  
Characteristics Analysis ◽  
Flow Theories

It is important for the research of flight characteristics to master the distribution of wind field and the character of turbulence intensity in a complex-terrain mountain. Based on the potential flow theories in fluid dynamics, a numerical simulation method of complex terrain including asymmetrical and symmetrical mountains has been developed in this paper. In particular, asymmetrical mountains are simulated by the combination of two transformed quarter-semiellipsoids. Furthermore, mountain-induced airflow is calculated based on potential flow theory, which could reflect the characteristic of wind field. As an example, the wind field near Dingling airport in Beijing has been simulated and analyzed by this method. The results demonstrate that this method is suitable and accurate for engineering practice, and also applicable for flight dynamics characteristics analysis of aircrafts.

Evaluation on Across-Wind Response of Tall Building According to Aerodynamic Shapes

2013 ◽  
Vol 823 ◽  
pp. 131-136
Author(s):  
Jang Youl You ◽  
Ki Pyo You ◽  
Young Moon Kim
Keyword(s):  
Wind Tunnel ◽  
Cross Sections ◽  
Turbulence Intensity ◽  
Suburban Area ◽  
Light Weight ◽  
Wind Tunnel Tests ◽  
Large Cities ◽  
High Rise ◽  
Type Form ◽  
Wind Response

High-rise buildings constructed in large cities are thin and long in their shape and are both unconventional and light-weight. The purpose of this study is to reduce the across-wind response of high-rise buildings (unconventional) under the influence of wind load. As a means to change the external shape of high-rise buildings, we selected the flat Y-type form. It is generally applied in domestic high-rise buildings for examination. Wind tunnel tests take place on 12 high-rise buildings, composed of three different Y-type shapes such as basic square forms with square cross sections and unconventional forms, in a suburban area (α=0.15) with a turbulence intensity of 10%.

Design and Aerodynamic Characteristics Study of a Spherical Aircraft

2013 ◽  
Vol 662 ◽  
pp. 612-615
Author(s):  
Peng Li ◽  
Yan Heng Zhang ◽  
Han Xu Sun ◽  
Hao Pan
Keyword(s):  
Numerical Simulation ◽  
Simulation Method ◽  
Aerodynamic Characteristics ◽  
Aircraft Structure ◽  
Research Results ◽  
Aerodynamic Model ◽  
Numerical Simulation Method ◽  
Cfd Numerical Simulation

In order to achieve the goals of small aircraft’s taking off and landing in any posture and the protection of propeller, a new single-propeller spherical aircraft structure was proposed, which had the capacity of flying in the air and walking on the ground simultaneously. An aerodynamic model of the aircraft was built. The aerodynamic characteristics of the spherical aircraft, including the lift and the anti-torque and the generated torque of the flow deflectors under the propeller’s down airflow, are studied in depth by means of CFD numerical simulation method. A reasonable design and installation program is proposed according to the research results.

scholarly journals Aerodynamic study of a suspension bridge deck by CFD simulations, wind tunnel tests and full-scale observations

2021 ◽  
Vol 1201 (1) ◽  
pp. 012007
Author(s):  
I. Kusano ◽  
E. Cheynet ◽  
J. B. Jakobsen ◽  
J. Snæbjörnsson
Keyword(s):  
Wind Tunnel ◽  
Wind Tunnel Test ◽  
Suspension Bridge ◽  
Aerodynamic Characteristics ◽  
Full Scale ◽  
Navier Stokes ◽  
Cfd Simulations ◽  
Wind Tunnel Tests ◽  
Long Span Bridges ◽  
Wide Range

Abstract Assessing the aerodynamic characteristics of long-span bridges is fundamental for their design. Depending on the terrain complexity and local wind conditions, episodes of large angles of attack (AoA) of 15° may be observed. However, such large AoAs ( above 10°) are often overlooked in the design process. This paper studies the aerodynamics properties of a flow around a single-box girder for a wide range of AoAs, from –20° to 20°, using numerical simulations. The simulations are based on a 2D unsteady Reynolds-averaged Navier–Stokes (URANS) approach using the k − ω SST turbulence model with a Reynolds number of 1.6 × 105. Numerically obtained aerodynamic static coefficients were compared to wind tunnel test data. The CFD results were generally in good agreement with the wind tunnel tests, especially for small AoAs and positive AoAs. More discrepancies were observed for large negative AoA, likely due to the limitation of modelling 3D railings with 2D simulations. The simulated velocity deficit downstream of the deck was consistent with the one measured in full-scale using short-range Doppler wind lidar instruments. Finally, the Strouhal number from the CFD simulations were in agreement with the value obtained from the full-scale data.

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