涡流脉冲多普勒信号的计算机仿真研究

Computer simulation research on pulsed Doppler signals from vortices

提出一种涡流脉冲多普勒信号的计算机仿真方法，产生了各种给定条件下的仿真涡流多普勒信号。对这些仿真信号进行短时傅里叶分析，求出相应的最大频率、平均频率和频谱宽度等曲线。通过研究这些曲线得到的频谱参数和仿真时给定的采样容积位置、采样容积大小、涡流中心间距、无涡流血流速度、涡流最大旋转速度之间的联系，找出利用脉冲多普勒技术检测涡流的敏感参数。

A computer simulation method for pulsed Doppler signals from vortices was proposed to generate simulated vortex Doppler signals under various given circumstances. The relative waveforms, such as maximum frequency, mean frequency and bandwidth, were obtained using the short time Fourier analysis of those simulated signals. The relations were studied between some spectrum parameters and given simulation conditions, such as the position and the size of the sampling volume, the distance between two vortices, the free stream velocity and the maximum peripheral velocity of the vortex. The sensitive parameters were found to detect vortices using the pulsed Doppler techniques.