Multi-dimensional particle sizing techniques
Multi-dimensional particle sizing techniques
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DOI：
10.1007/s00348-005-1009-1
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发表时间：
2005-06
影响因子：
2.4
通讯作者：
N. Damaschke;H. Nobach;T. Nonn;Nikolay Semidetnov;C. Tropea
中科院分区：
文献类型：
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作者：
N. Damaschke;H. Nobach;T. Nonn;Nikolay Semidetnov;C. Tropea
讨论并比较了两种用于球形颗粒多维尺寸测量的技术：干涉粒子成像技术（IPI）和一种称为全局相位多普勒（GPD）的新技术。IPI技术在以往的各种研究中是已知的，它使用激光片照射粒子场，而GPD技术是一种新的方法，它使用两个相交的激光片。所得到的远场干涉图是由粒子的类似散射阶的干涉产生的，类似于相位多普勒技术。对这两种技术的远场干扰进行了描述。这两种多维粒度技术通过散焦成像系统对远场散射光进行采样。通过测量离焦图像中干涉条纹的角频率来确定被激光光片照射的每个液滴的直径。结合脉冲激光，该技术还可以确定粒子的速度，类似于粒子跟踪测速（PTV）。然而，每个粒子离焦图像的大小也取决于粒子垂直于激光片的位置，因此，通过适当的校准，也可以获得速度的第三分量。IPI和GPD这两种技术在实现和预期准确性方面相互比较。本文还讨论了两种技术结合的可能性。介绍了一些新的信号处理方法，并用模拟信号和真实信号进行了演示。
Two techniques for multi-dimensional sizing of spherical particles are discussed and compared with one another: interferometric particle imaging (IPI) and a novel technique known as global phase Doppler (GPD). Whereas the IPI technique is known from various previous studies and uses a laser light sheet illumination of the particle field, the GPD technique is a new method and employs two intersecting laser light sheets. The resulting far-field interference pattern arises from the interference of like scattering orders from the particle, similar to the phase Doppler technique. A description of this far-field interference is given for both techniques. Both multi-dimensional particle sizing techniques sample the scattered light in the far-field by means of a defocused imaging system. The diameter of each droplet illuminated by the laser light sheet(s) is determined by measuring the angular frequency of the interference fringes in the defocused images. Combined with a pulsed laser, the technique also allows the velocity of the particle to be determined, similar to particle tracking velocimetry (PTV). However, the size of the defocused image of each particle also depends on the position of the particle perpendicular to the laser sheet, hence, with appropriate calibration, the third component of velocity is also accessible. The two techniques, IPI and GPD, are compared to one another in terms of implementation and expected accuracy. Possibilities of combining the two techniques are also discussed. Some novel approaches for the signal processing have been introduced and demonstrated with simulated and real signals.