考虑相位角的脉动风场模拟

为克服考虑相位角后风谱密度矩阵可能不正定而无法进行Cholesky分解的困难,提出了一种基于插值技术的改进风场模拟方法。首先依据风谱密度矩阵的正定性或不正定性将模拟风频范围划分为正定区间和不正定区间。在正定区间内,可直接将风谱密度矩阵进行Cholesky分解。而在不正定区间内,可采用插值技术获得风谱密度矩阵的分解式。然后运用谐波合成法模拟出全部风频范围内的脉动风速。数值算例表明:该方法具有较高的精度,且模拟结果能较好地符合自然风的基本特性。

SIMULATION OF TURBULENT WIND FIELD WITH PHASE ANGLE

An improved method based on the interpolation technique is proposed to simulate a wind field. It overcomes the difficulty that the Cholesky’s decomposition of a wind spectral density matrix can not be executed due to its possible indefiniteness with phase angle. The interval of the simulant wind frequency can be divided into two parts: definite interval and indefinite interval according to the definiteness or indefiniteness of the wind spectral density matrix. In definite interval, the Cholesky’s decomposition can be directly executed, while in indefinite interval, the decomposition expression can be obtained by the interpolation technique. Then the turbulent wind velocity can be simulated with the spectral representation method in entire intervals of the wind frequency. Numerical examples show that the method is of high precision and the simulant results accord with the basic characteristics of natural wind.