Engineering Simulation Method for Three-Dimensional Wind Field Over Complex Terrains at Low Altitude

2013 ◽  
Author(s):  
Hu Huanran ◽  
Hong Guanxin
Keyword(s):  
Wind Field ◽  
Three Dimensional ◽  
Simulation Method ◽  
Low Altitude

Transient Simulation of a Three-Dimensional Moving Downburst

2012 ◽  
Vol 446-449 ◽  
pp. 3875-3878
Author(s):  
Bai Feng Ji ◽  
Wei Lian Qu
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Computational Fluid Dynamics ◽  
Wind Field ◽  
Three Dimensional ◽  
Simulation Method ◽  
Transient Simulation ◽  
Dynamics Simulation ◽  
Transmission Tower ◽  
Transient Wind

Thunderstorm microbursts, which are sources of extreme wind loadings in nature, have caused numerous structural failures, especially collapses of transmission tower around the world. Numerical simulation using computational fluid dynamics (CFD) has recently made significant progress in simulating downbursts. In this paper, transient simulation of a three-dimensional moving downburst was studied using computational fluid dynamics simulation method. Transient simulation of a three-dimensional moving downburst was conducted using time-filtered Reynolds Averaged Navier-Stokes (RANS) numerical simulation method. The three-dimensional transient wind field characteristics in a moving downburst were studied in detail. The results indicate that transient wind field characteristics in a moving downburst present quite different characteristics compared with stationary downburst at different heights and radial positions.

Study on Three-Dimensional Wind Field Characteristics of Thunderstorm Microbursts Using Computational Fluid Dynamics

2011 ◽  
Vol 243-249 ◽  
pp. 5033-5036
Author(s):  
Bai Feng Ji ◽  
Wei Lian Qu ◽  
Yan Li ◽  
Yi Fei Wang ◽  
Zhong Shan He
Keyword(s):  
Wind Field ◽  
Computational Simulation ◽  
Three Dimensional ◽  
Simulation Method ◽  
Computational Method ◽  
Navier Stokes ◽  
Transmission Tower ◽  
Lower Altitude ◽  
Structural Failures ◽  
Wind Distribution

Thunderstorm microbursts, which are sources of extreme wind loadings in nature, have caused numerous structural failures, especially collapses of transmission tower around the world. It is important to study wind field characteristics of thunderstorm microbusts from the perspective of wind-resistant design. In this paper, the three-dimensional wind field characteristics of thunderstorm microbursts were studied using computational simulation method. Firstly, the three-dimensional wind field of microburst was computational simulated using time-filtered Reynolds Averaged Navier-Stokes (RANS) numerical computational method. Then, the three-dimensional wind field characteristics including the wind distribution of wind velocity at different heights, the wind contours at lower altitude positions were studied in detail. The results indicate that the three-dimensional wind field of microbursts winds presents quite different characteristics at different heights and radial positions.

Three-Dimensional Wind Field Simulation on the Two Typical Roofs of the Building

2014 ◽  
Vol 986-987 ◽  
pp. 685-688
Author(s):  
Shu Qin Liu ◽  
Zhong Guo Bian ◽  
Yuan Bo Cai ◽  
Fang Zhao
Keyword(s):  
Numerical Simulation ◽  
Theoretical Analysis ◽  
Wind Energy ◽  
Wind Field ◽  
Three Dimensional ◽  
Simulation Method ◽  
Energy Utilization ◽  
Wind Field Simulation ◽  
Field Simulation ◽  
Important Significance

Wind energy utilization in the building environment has the advantage that it can avoid transporting effectively, especially it has important significance for residents without electricity. This paper mainly analyzed the basic situation of three-dimensional wind field around the buildings with the theoretical analysis and CFD numerical simulation method. By simulating the wind with different directions and different speeds, the characteristics of the wind field around single flat and pitched roof building are analyzed.

Two Dimension Numerical Simulation of Airflow over Complex Terrains at Low Altitude

2013 ◽  
Vol 756-759 ◽  
pp. 4728-4734
Author(s):  
Chu Tang ◽  
Huan Ran Hu ◽  
Guan Xin Hong
Keyword(s):  
Numerical Simulation ◽  
Wind Field ◽  
Simulation Method ◽  
Two Dimensional ◽  
Numerical Examples ◽  
Spline Curve ◽  
Flight Simulators ◽  
Low Altitude ◽  
Flow Theories ◽  
Cubic Spline Curve

In order to avoid the problems of existing methods, a numerical simulation method for two-dimensional airflow over complex terrains is developed in this paper for the engineering use of flight dynamics. Based on the potential flow theories, the effects of terrains on the wind field are considered by a serial of two-dimensional vortexes, whose strengths are solved by combining with the ground boundary conditions. Numerical examples are studied by the proposed method, and the method is also evaluated by comparing the results with ones from the existing method. The result shows that the two-dimensional profile of complex terrains could be described by a cubic spline curve precisely. The computation procedure proposed in this paper is very simple and efficient, and it could provide a result of wind field with considerable accuracy. Therefore, this method could be used for flight principle evaluation and flight simulators. Finally, through simulate flight path, discussing effect of terrains on track.

Dynamic simulation of wind field in three-dimensional display space considering particle swarm algorithm fuzzy logic

2021 ◽  
pp. 1-6
Author(s):  
Honglei Xu ◽  
Linhuan Wang
Keyword(s):  
Fuzzy Logic ◽  
Dynamic Simulation ◽  
Wind Field ◽  
Three Dimensional ◽  
Measurement Data ◽  
Particle Swarm ◽  
Particle Swarm Algorithm ◽  
Three Dimensional Display ◽  
Swarm Algorithm ◽  
Synchronous Measurement

In order to improve the accuracy of dynamic detection of wind field in the three-dimensional display space, system software is carried out on the actual scene and corresponding airborne radar observation information data, and the particle swarm algorithm fuzzy logic algorithm is introduced into the wind field dynamic simulation process in three-dimensional display space, to analyze the error of the filtering result in detail, to process the hurricane Lily Doppler radar measurement data with the optimal adaptive filtering according to the error data. The three-dimensional wind field synchronous measurement data obtained by filtering was compared with three-dimensional wind field synchronous measurement data of the GPS dropsonde in this experiment, the sea surface wind field measurement data of the multi-band microwave radiometer, and the wind field data at aircraft altitude.

scholarly journals Strata behavior and control strategy of backfilling collaborate with caving fully-mechanized mining

2020 ◽  
Vol 12 (1) ◽  
pp. 703-717
Author(s):  
Yin Wei ◽  
Wang Jiaqi ◽  
Bai Xiaomin ◽  
Sun Wenjie ◽  
Zhou Zheyuan
Keyword(s):  
Numerical Simulation ◽  
Control Strategy ◽  
Three Dimensional ◽  
Simulation Method ◽  
Mine Pressure ◽  
Hydraulic Support ◽  
Transition Area ◽  
Pressure Concentration ◽  
Strata Behavior ◽  
And Control

AbstractThis article analyzes the technical difficulties in full-section backfill mining and briefly introduces the technical principle and advantages of backfilling combined with caving fully mechanized mining (BCCFM). To reveal the strata behavior law of the BCCFM workface, this work establishes a three-dimensional numerical model and designs a simulation method by dynamically updating the modulus parameter of the filling body. By the analysis of numerical simulation, the following conclusions about strata behavior of the BCCFM workface were drawn. (1) The strata behavior of the BCCFM workface shows significant nonsymmetrical characteristics, and the pressure in the caving section is higher than that in the backfilling section. φ has the greatest influence on the backfilling section and the least influence on the caving section. C has a significant influence on the range of abutment pressure in the backfilling section. (2) There exits the transition area with strong mine pressure of the BCCFM workface. φ and C have significant effect on the degree of pressure concentration but little effect on the influence range of strong mine pressure in the transition area. (3) Under different conditions, the influence range of strong mine pressure is all less than 6 m. This article puts forward a control strategy of mine pressure in the transition area, which is appropriately improving the strength of the transition hydraulic support within the influence range (6 m) in the transition area according to the pressure concentration coefficient. The field measurement value of Ji15-31010 workface was consistent with numerical simulation, which verifies the reliability of control strategy of the BCCFM workface.

scholarly journals Engineering Comprehensive Model of Complex Wind Fields for Flight Simulation

Aerospace ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 145
Author(s):  
Jianwei Chen ◽  
Liangming Wang ◽  
Jian Fu ◽  
Zhiwei Yang
Keyword(s):  
Wind Field ◽  
Three Dimensional ◽  
Great Influence ◽  
Spatial Location ◽  
Flight Simulation ◽  
Comprehensive Model ◽  
Flight Trajectory ◽  
Wind Fields ◽  
Wind Field Simulation ◽  
Low Level Jet

A complex wind field refers to the typical atmospheric disturbance phenomena existing in nature that have a great influence on the flight of aircrafts. Aimed at the issues involving large volume of data, complex computations and a single model in the current wind field simulation approaches for flight environments, based on the essential principles of fluid mechanics, in this paper, wind field models for two kinds of wind shear such as micro-downburst and low-level jet plus three-dimensional atmospheric turbulence are established. The validity of the models is verified by comparing the simulation results from existing wind field models and the measured data. Based on the principle of vector superposition, three wind field models are combined in the ground coordinate system, and a comprehensive model of complex wind fields is established with spatial location as the input and wind velocity as the output. The model is applied to the simulated flight of a rocket projectile, and the change in the rocket projectile’s flight attitude and flight trajectory under different wind fields is analyzed. The results indicate that the comprehensive model established herein can reasonably and efficiently reflect the influence of various complex wind field environments on the flight process of aircrafts, and that the model is simple, extensible, and convenient to use.

scholarly journals Study of the Effect of Centrifugal Force on Rotor Blade Icing Process

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Zhengzhi Wang ◽  
Chunling Zhu
Keyword(s):  
Numerical Simulation ◽  
Centrifugal Force ◽  
Rotor Blade ◽  
Flow Direction ◽  
Three Dimensional ◽  
Simulation Method ◽  
Two Phase ◽  
Numerical Simulation Method ◽  
Calculation Results ◽  
Flow Field Characteristics

In view of the rotor icing problems, the influence of centrifugal force on rotor blade icing is investigated. A numerical simulation method of three-dimensional rotor blade icing is presented. Body-fitted grids around the rotor blade are generated using overlapping grid technology and rotor flow field characteristics are obtained by solving N-S equations. According to Eulerian two-phase flow, the droplet trajectories are calculated and droplet impingement characteristics are obtained. The mass and energy conservation equations of ice accretion model are established and a new calculation method of runback water mass based on shear stress and centrifugal force is proposed to simulate water flow and ice shape. The calculation results are compared with available experimental results in order to verify the correctness of the numerical simulation method. The influence of centrifugal force on rotor icing is calculated. The results show that the flow direction and distribution of liquid water on rotor surfaces change under the action of centrifugal force, which lead to the increasing of icing at the stagnation point and the decreasing of icing on both frozen limitations.

Thermo-mechanical coupling particle simulation of three-dimensional large-scale non-isothermal problems

2017 ◽  
Vol 34 (5) ◽  
pp. 1551-1571 ◽  
Author(s):  
Ming Xia
Keyword(s):  
Large Scale ◽  
Three Dimensional ◽  
Simulation Method ◽  
Particle Simulation ◽  
Similarity Criteria ◽  
Particle Model ◽  
Length Scale ◽  
Content Type ◽  
Mechanical Coupling ◽  
Particle Simulation Method

Purpose The main purpose of this paper is to present a comprehensive upscale theory of the thermo-mechanical coupling particle simulation for three-dimensional (3D) large-scale non-isothermal problems, so that a small 3D length-scale particle model can exactly reproduce the same mechanical and thermal results with that of a large 3D length-scale one. Design/methodology/approach The objective is achieved by following the scaling methodology proposed by Feng and Owen (2014). Findings After four basic physical quantities and their similarity-ratios are chosen, the derived quantities and its similarity-ratios can be derived from its dimensions. As the proposed comprehensive 3D upscale theory contains five similarity criteria, it reveals the intrinsic relationship between the particle-simulation solution obtained from a small 3D length-scale (e.g. a laboratory length-scale) model and that obtained from a large 3D length-scale (e.g. a geological length-scale) one. The scale invariance of the 3D interaction law in the thermo-mechanical coupled particle model is examined. The proposed 3D upscale theory is tested through two typical examples. Finally, a practical application example of 3D transient heat flow in a solid with constant heat flux is given to illustrate the performance of the proposed 3D upscale theory in the thermo-mechanical coupling particle simulation of 3D large-scale non-isothermal problems. Both the benchmark tests and application example are provided to demonstrate the correctness and usefulness of the proposed 3D upscale theory for simulating 3D non-isothermal problems using the particle simulation method. Originality/value The paper provides some important theoretical guidance to modeling 3D large-scale non-isothermal problems at both the engineering length-scale (i.e. the meter-scale) and the geological length-scale (i.e. the kilometer-scale) using the particle simulation method directly.

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