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.

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.

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 the Downburst Field Characteristics under the Influence of Two-Dimensional Continuous Mountains at Different Distance

2014 ◽  
Vol 580-583 ◽  
pp. 3111-3114
Author(s):  
Yi Sun ◽  
Yuan Ze Wu ◽  
Hai Tao Shi ◽  
Bai Feng Ji
Keyword(s):  
Numerical Simulation ◽  
Boundary Layer ◽  
Wind Field ◽  
Strong Wind ◽  
Two Dimensional ◽  
Field Characteristic ◽  
Main Factors ◽  
Cfd Numerical Simulation ◽  
The Impact

Downburst is an outburst strong wind on or near the ground, and its wind field characteristics are significantly different from boundary layer winds. Continuous mountains at different distance are one of the main factors for the influence of downburst wind field characteristic. In this thesis, the changes of the wind field characteristics under the influence of continuous mountains at different distance after the downburst happened are studied by CFD numerical simulation. The impact of downburst is analysed and summarized through the charts.

Wind Field Numerical Simulation of Long-Span Bridge

2013 ◽  
Vol 361-363 ◽  
pp. 1094-1100
Author(s):  
Jian Guo ◽  
Wei Chang Gan ◽  
Ding Yu Jiang ◽  
Bing Nan Sun ◽  
Wei Peng
Keyword(s):  
Numerical Simulation ◽  
Wind Field ◽  
Simulation Method ◽  
Filter Method ◽  
Linear Filter ◽  
Wind Field Simulation ◽  
Long Span ◽  
Long Span Bridge ◽  
Target Spectrum ◽  
Main Girder

In the research on calculation of interaction of wind and structure, the key to the question is wind field numerical simulation. This paper introduces a practical wind field simulation method of long-span Bridge. The main bridge of Jintang Bridge was analyzed as engineering example, which is a cross-sea cable stayed bridge in Zhoushan of Zhejiang Province , and the linear filter method was applied to calculate along-wind and vertical wind field on main girder, MATLAB program also was adopted to simulate wind field of long-span Bridge. The results show that simulated spectrum is in better agreement with the target spectrum, which verifies validity of the method and correctness of the program.

Analysis of Elastic Moduli and Fracture of Concrete with Nature Element Method in Mesoscale

2012 ◽  
Vol 430-432 ◽  
pp. 640-646
Author(s):  
Hong Chang Qu ◽  
Bei Yi Zhang ◽  
Feng Zhang
Keyword(s):  
Numerical Simulation ◽  
Crack Propagation ◽  
Meshless Method ◽  
Elastic Moduli ◽  
Simulation Method ◽  
Two Dimensional ◽  
Stress Strain ◽  
Natural Element Method ◽  
Natural Element ◽  
Element Method

Based on the natural element method (NEM), which is a kind of meshless method, a two-dimensional numerical simulation method is developed and applied to the analysis of overall elastic moduli and fracture of solids. The calculated results are compared with the experimental solutions for overall elastic moduli, fracture and stress-strain curves for two, three and four graded concrete with FEM solutions in plane. The numerical results show the presented method is easy to implement and very accurate, especially for solving the problems of crack propagation.

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.

Sign in / Sign up

Export Citation Format

Share Document