scholarly journals A Spectrum Correction Method Based on Optimizing Turbulence Intensity

2021 ◽  
Vol 12 (1) ◽  
pp. 66
Author(s):  
Wenwu Yi ◽  
Ziqi Lu ◽  
Junbo Hao ◽  
Xinge Zhang ◽  
Yan Chen ◽  
...  
Keyword(s):  
Turbulence Intensity ◽  
Wind Field ◽  
Dimensional Space ◽  
Correction Method ◽  
Turbulent Wind ◽  
Wind Field Simulation ◽  
Simulation Efficiency ◽  
Spectral Correction ◽  
Spectral Representation Method ◽  
Speed Fluctuation

Based on the classical spectral representation method of simulating turbulent wind speed fluctuation, a harmonic superposition algorithm was introduced in detail to calculate the homogeneous turbulence wind field simulation in space. From the view of the validity of the numerical simulation results in MATLAB and the simulation efficiency, this paper discussed the reason for the bias existing between three types of turbulence intensity involved in the whole simulation process: simulated turbulence intensity, setting reference turbulence intensity, and theoretical turbulence intensity. Therefore, a novel spectral correction method of a standard deviation compensation coefficient was proposed. The simulation verification of the correction method was carried out based on the Kaimal spectrum recommended by IEC61400-1 by simulating the uniform turbulent wind field in one-dimensional space at the height of the hub of a 15 MW wind turbine and in two-dimensional space in the rotor swept area. The results showed that the spectral correction method proposed in this paper can effectively optimize the turbulence intensity of the simulated wind field, generate more effective simulation points, and significantly improve the simulation efficiency.

scholarly journals Non-Stationary Turbulent Wind Field Simulation of Long-Span Bridges Using the Updated Non-Negative Matrix Factorization-Based Spectral Representation Method

2019 ◽  
Vol 9 (24) ◽  
pp. 5506
Author(s):  
Zidong Xu ◽  
Hao Wang ◽  
Han Zhang ◽  
Kaiyong Zhao ◽  
Hui Gao ◽  
...  
Keyword(s):  
Wind Field ◽  
Spectral Representation ◽  
Wind Fields ◽  
Turbulent Wind ◽  
Long Span Bridges ◽  
Long Span ◽  
Spectral Representation Method ◽  
Representation Method ◽  
Turbulent Wind Field ◽  
Non Negative Matrix Factorization

Numerical simulation of the turbulent wind field on long-span bridges is an important task in structural buffeting analysis when it comes to the system non-linearity. As for non-stationary extreme wind events, some efforts have been paid to update the classic spectral representation method (SRM) and the fast Fourier transform (FFT) has been introduced to improve the computational efficiency. Here, the non-negative matrix factorization-based FFT-aided SRM has been updated to generate not only the horizontal non-stationary turbulent wind field, but also the vertical one. Specifically, the evolutionary power spectral density (EPSD) is estimated to characterize the non-stationary feature of the field-measured wind data during Typhoon Wipha at the Runyang Suspension Bridge (RSB) site. The coherence function considering the phase angles is utilized to generate the turbulent wind fields for towers. The simulation accuracy is validated by comparing the simulated and target auto-/cross-correlation functions. Results show that the updated method performs well in generating the non-stationary turbulent wind field. The obtained wind fields will provide the research basis for analyzing the non-stationary buffeting behavior of the RSB and other wind-sensitive structures in adjacent regions.

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.

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