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.

Static Force Measurement Technology Wind Tunnel Test

2013 ◽  
Vol 423-426 ◽  
pp. 1689-1692
Author(s):  
Dun Jin ◽  
Yue Ming Yang ◽  
Jie Wu ◽  
Li Min Song ◽  
Song Li
Keyword(s):  
Numerical Simulation ◽  
Wind Tunnel ◽  
Force Measurement ◽  
Spin Dynamics ◽  
Limit State ◽  
Wind Tunnel Test ◽  
Measurement Technology ◽  
Static Force ◽  
Aerodynamic Test ◽  
High Angles Of Attack

Static force measurement aerodynamic wind tunnel test data provided by the aircraft normally used to predict the stall characteristics, predicted aircraft deviated,spin Sensitivities, numerical simulation of aircraft stall, spin dynamics and so on. Based on practical flight, the paper analyzed the harm of limit state flight-spin to the flight safe, emphasized the static force test techniques at high angles of attack, and obtained a series of aerodynamic test date, managed them to spin prediction analysis.

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.

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

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.

Wind Tunnel Experimental Research on Flutter Stability of Liujiaxia Bridge

2013 ◽  
Vol 361-363 ◽  
pp. 1105-1109
Author(s):  
Chun Sheng Shu
Keyword(s):  
Wind Tunnel ◽  
Critical Velocity ◽  
Experimental Research ◽  
Wind Tunnel Test ◽  
Suspension Bridge ◽  
Wind Tunnel Tests

Liujiaxia Bridge is a truss stiffening girder suspension bridge which span is 536m, and it is the narrowest suspension bridge with the same scale, so the problems of flutter stability are prominent. Results of wind tunnel test show that its critical velocity cannot meet the requirements without any aerodynamic measures. Based on above considerations, seven kinds of aerodynamic measures are proposed, respectively wind tunnel tests are conducted. The results show that the program, in which the upper central stable board is 1.12m high and the under central stable board is 1.28m high, can meet the requirements. The results of this study provide some references to solving the problem of wind-resistant stability of narrow deck suspension bridge.

Videogrammetric Measurement for Model Displacement in Wind Tunnel Test

2011 ◽  
Vol 130-134 ◽  
pp. 103-107 ◽  
Author(s):  
Zheng Yu Zhang ◽  
Shui Liang Wang ◽  
Yan Sun
Keyword(s):  
Image Processing ◽  
Wind Tunnel ◽  
Wind Tunnel Test ◽  
Accurate Data ◽  
Exterior Orientation ◽  
Wind Tunnel Tests ◽  
Key Techniques ◽  
Transonic Wind Tunnel

It is crucial measuring position and attitude of model to gain the precise and accurate data in wind tunnel tests. The model displacement videogrammetric measurement (MDVM) system and its key techniques such as the exterior orientation with big rotation angles and large-overlap, mark points, image processing and calibration based on the known distances are therefore presented. The practice example in Asia's largest (2.4m) transonic wind tunnel has demonstrated the MDVM system and its key techniques are correct and feasible, and they have application value.

scholarly journals Galloping Stability and Aerodynamic Characteristic of Iced Transmission Line Based on 3-DOF

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Xiaohui Liu ◽  
Ming Zou ◽  
Chuan Wu ◽  
Bo Yan ◽  
Mengqi Cai
Keyword(s):  
Wind Speed ◽  
Transmission Line ◽  
Angle Of Attack ◽  
Wind Tunnel Test ◽  
Simulation Method ◽  
Theoretical Formula ◽  
Aerodynamic Load ◽  
Line System ◽  
Critical Wind Speed ◽  
The Stability

A new calculation method of critical wind speed based on three degrees of freedom (3-DOF) is proposed for galloping problem of iced transmission line. Based on the quasistatic theory, the aerodynamic load of iced transmission line is obtained, which considers the influence of transverse and torsional motion on the relative wind angle of attack. Finally, the equivalent galloping model of 3-DOF iced transmission line is established. At the initial angle of attack, the aerodynamic load is expanded by Taylor, and the unsymmetrical linear aerodynamic coefficient matrix is obtained. The Routh–Hurwitz criterion is used to judge the stability of iced transmission line system, and then the critical wind speed is calculated. The in-plane and out-plane frequencies corresponding to the first-order mode of the transmission line are solved by the analytical method and numerical simulation method. The results obtained by the two methods are compared and verified. The influence of dimensionless transmission line parameter λ on the in-plane and out-of-plane frequencies is discussed. The aerodynamic coefficients of the iced transmission line are measured by wind tunnel test and the aerodynamic characteristics are analyzed. According to the theoretical formula, the critical wind speed is calculated by MATLAB. The critical wind speed determined in this paper is compared with the critical wind speed determined by Den Hartog and Nigol theory. The influences of torsional vibration frequency, ice thickness, and ice shape on critical wind speed are analyzed. The research results of this paper have important theoretical significance for the stability judgment of iced transmission lines.

Design of a Wind Tunnel Test Section for Single Airfoil Configuration With Real-Time Lift Force Control

2017 ◽  
Author(s):  
Aline Aguiar da Franca ◽  
Dirk Abel
Keyword(s):  
Wind Tunnel ◽  
Wind Turbine ◽  
Real Time ◽  
Force Control ◽  
Test Section ◽  
Lift Force ◽  
Angle Of Attack ◽  
Wind Tunnel Test ◽  
Wiener Model ◽  
Dynamic Matrix

This article presents a concept of test section for a closed-return wind tunnel, where the lift force of an airfoil, which depends on the angle of attack, is controlled in real-time. This airfoil is used to represent a wind turbine blade. The lift force of the blades is what produces the rotor torque of the wind turbine. This torque determines the amount of energy that will be captured by the wind turbine. The linear dynamics of the motor used to change the angle of attack and the static non-linearity of the airfoil are modeled as a Wiener model. The Quadratic Dynamic Matrix Controller based on Wiener model with linearizing pre-compensation is implemented to keep the lift force constant, which is desirable to avoid mechanical loads for wind turbine applications.

Wind Load on Complex-Shape Building

2010 ◽  
Vol 163-167 ◽  
pp. 4389-4394
Author(s):  
Cheng Qi Wang ◽  
Zheng Liang Li ◽  
Zhi Tao Yan ◽  
Qi Ke Wei
Keyword(s):  
Numerical Simulation ◽  
Wind Tunnel ◽  
Negative Pressure ◽  
Complex Shape ◽  
Wind Tunnel Test ◽  
Wind Load ◽  
Negative Pressures ◽  
Windward Surface

Wind load on complex-shape building, the wind tunnel test and numerical simulation were carried out. The two technologies supplement each other and their results meet well. There are mainly positive pressures on the windward surface, negative pressures on the roof, the leeward surface and the side. Especially, negative pressure is higher in the leeward region of the building corner. Its effect induced by the shape of the complex-shape building is remarkable.

The Research of Subspan Oscillation and Configuration of Spacer for Transmission Line

2012 ◽  
Vol 614-615 ◽  
pp. 1855-1861
Author(s):  
Yu Xian Di ◽  
Kuan Jun Zhu ◽  
Cao Lan Liu
Keyword(s):  
Numerical Simulation ◽  
Transmission Lines ◽  
Simulation Method ◽  
Computational Method ◽  
Analysis Model ◽  
Element Analysis ◽  
Finite Element Analysis Model ◽  
The Finite Element Analysis ◽  
Computer Aided ◽  
Calculation Procedures

Based on the summarization of domestic and foreign experience, the computational method of spacer configuration was developed in order to depress sub-span oscillation principally. The requirements of the reverse recovery characteristics were considered. The computer-aided calculation procedures were programmed. The finite element analysis model of sub-span oscillation for cable-spacer system was established. The inherence modal and amplitude for sub-span oscillation of bundled transmission lines were calculated by using numerical simulation method. The dynamic configurations were analyzed by using the parameters of the cable and spacer obtained from vibration testing.

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