考虑声波折射的声学锅炉温度场测量技术的研究

A Sonic Measuring Technique of Furnace Temperature Fields Taking into Account the Refraction of Sound Waves

根据炉膛断面理想的温度分布函数,给出了二维单峰圆对称模型温度场,数值计算了声波在模型温度场中沿直线路径的传播时间,用声学CT算法进行了温度场的重建仿真。根据光学Fermat原理和数学变分方法建立的声波传播路径的数学模型,数值计算了声波在模型温度场中的折射传播路径,发现声波在非均匀温度场中不沿直线传播,其传播路径朝向温度较高的区域发生弯曲。利用得到的声波实际传播路径,用声学CT算法重建了温度场,结果表明考虑声波折射后建立的声学法二维温度场精确度得到提高。

Based on the ideal temperature distribution function of furnace's cross-section, a 2-dimensional, circular symmetric, single-peaked model temperature field is given. The straight-line propagation time of sonic waves in the model temperature field numerically calculated, and the reconstruction simulation of the temperature field accomplished with acoustic CT algorithm. The refracted propagation path of sonic waves in the in the model's temperature field is numerically calculated with Fermat's theory and by variational calculation, which shows that sonic waves do not propagate in along straight lines in fields of non-uniform temperature, but curve towards zones of higher temperature. Reconstructed temperature fields, calculated by acoustic CT algorithm and starting from actual propagation paths of sonic waves already obtained that the accuracy of 2-dimensional temperature fields obtained by acoustic algorithm is improved by taking into account of the sonic waves' refraction. Figs 5 and refs 7