An Efficient Simulation Method of 3D Wind Field Based on Delay Effect

Abstract

The invention discloses a three-dimensional wind field high-efficiency simulation method based on delay effect, and belongs to the technical field of structural wind engineering. The main steps of generating the time history of wind speed in the present invention are as follows: determine the coordinates of the simulation point and the initial coordinate system according to the structural drawing, transform the coordinate system so that the Y axis is parallel to the wind speed direction, and obtain the three-dimensional model of N structural simulation points, and All the simulation points of the 3D model are projected onto the target two-dimensional plane, and the simulation points are transformed into projection points in the two-dimensional plane. The wind speed delay time is calculated, that is, the time required for each point to project on the target plane, and the two-dimensional coherence function is used to consider To simulate the horizontal and vertical spatial correlation of different points, use the "harmonic superposition method" to generate fluctuating wind speed, and use the delay time to obtain the time history of wind speed at all points. The statistical characteristics of the data obtained by the time delay method of the present invention are similar to the results of the traditional three-dimensional method, but the simulation efficiency is greatly improved, and the method is simple to operate and has a reasonable theoretical background.

Description

technical field [0001] The invention belongs to the technical field of structural wind engineering, in particular to a numerical simulation method for generating wind speed time histories. Background technique [0002] Wind disaster is one of the natural disasters that cause the greatest loss of personnel and property. For large structures, wind load is an important design load, and even plays a decisive role. The existing wind resistance design mainly adopts the methods of wind tunnel test, numerical simulation and field measurement. Numerical simulation is an important supplement to the test. The method is convenient and repeatable, and it can be used for wind load verification and design calculation. [0003] Wind loads imposed on structures require artificial synthesis of wind speed time histories with specific spectral density and spatial correlation as excitations. In engineering, natural wind is usually approximately regarded as a smooth Gaussian process with various...

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Problems solved by technology

However, with more and more large-scale structures, the number of variables in the simulation process will increase accordingly, and the dimension of the cross-spectral density matrix will increase. It will become more difficult to perform Cholesky decomposition on it, resulting in a greatly reduced computational efficiency.

Some scholars consider introducing the "Taylor Freeze Hypothesis" into the wind field simulation to replace the longitudinal spatial correlation of the wind field, and make a phase offset for the fluctuation of each frequency point. This method will increase the final superposition and summation. workload

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