23 publications from this institution
. This paper proposes a fractal-based technique for simulating multivariate nonstationary wind speed fields by the stochastic Weierstrass Mandelbrot function. Upon conducting a systematic fractal analysis, it was found that the structure function method is more suitable and reliable than the box counting method, variation method, and R/S analysis method for estimating the fractal dimension of the stochastic wind speed series. Wind field measurement at the meteorological gradient tower with a height of 356 m in Shenzhen was conducted during Typhoon Mangkhut (2018). Significant non-stationary properties and fractal dimensions of typhoon wind speed data at various heights were analyzed and used to demonstrate the effectiveness of the proposed multivariate typhoon wind speed simulation method. The multivariate wind speed components simulated by the proposed fractal-based method are in good agreement with the measured records in terms of the fractal dimension, standard deviation, probability density function, wind spectrum and cross-correlation coefficient.
A novel development of Embedded Large Eddy Simulation (ELES) model was proposed for urban wind field simulations, incorporating the synthetic volume force method integrated with the Graphic Processing Unit (GPU) parallel computing. By combining the advantages of RANS and LES, the proposed model enhances both computational efficiency and accuracy in comparison to conventional LES models. A validation simulation for the atmospheric boundary layer wind field was conducted to assess the accuracy of the proposed method. Subsequently, an ideal urban block was used to evaluate the influence of LES region sizes and the positioning of the RANS (Reynolds-Averaged Navier-Stokes)/LES interface on the simulation results. It was found that the positioning of the RANS/LES interface in the ELES model appears to have little effects on the mean wind field, while it does affect the fluctuating wind speed results. Comparative analysis with wind tunnel experiments and conventional large eddy simulation confirmed the efficacy of the proposed ELES with accelerated turbulence generation.
