Development and validation of an MRI-based method for 3D particle concentration measurement
Development and validation of an MRI-based method for 3D particle concentration measurement
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DOI：
10.1016/j.ijheatfluidflow.2018.04.006
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发表时间：
2018-06-01
影响因子：
2.6
通讯作者：
Eaton, John K.
中科院分区：
文献类型：
--
作者：
Borup, Daniel D.;Elkins, Christopher J.;Eaton, John K.
提出了一种利用磁共振成像（MRI）测量湍流中分散颗粒相体积分数的新方法MRP（Magnetic Resonance Particle Concentration）。在琼脂糖凝胶中悬浮的单个不锈钢颗粒附近拍摄的MRI图像显示出与浸没球体引起的均匀磁场干扰的分析解的良好一致性。对于颗粒的随机分布，先前在MRI文献中已经预测了MRI信号衰减速率（R-2（*））和颗粒体积分数（phi（v））之间的线性关系。研究了悬浮在琼脂糖凝胶小瓶中的各种类型的颗粒的这种关系。与理论观察到的颗粒具有高的磁化率从水的差异。R-2（*）也在含有均匀分布的钛颗粒的方形通道流中在两个完全湍流雷诺数下测量。实验结果再次同意与理论在大多数的通道的雷诺数研究。来自该流的数据用于在未来实验中检查MRP的预期SNR和动态范围。在通道的入口区域附近观察到一些差异，可能的解释包括流入流体和通道混合针阵列后面的大规模流动结构效应。最后，用该方法测量了钛颗粒注入带角肋方槽道湍流流中的三维浓度分布。的条纹的运输进行了定量分析，并在通道的几何形状中的一个小的不对称性被证明有重要的影响，颗粒条纹的平均运输。
A novel method, denoted MRP (short for Magnetic Resonance Particle concentration), was developed to obtain 3D volume fraction measurements for a dispersed particulate phase in turbulent water flows using Magnetic Resonance Imaging (MRI). MRI images taken near a single stainless steel particle suspended in agarose gel showed good agreement with the analytical solution for the disturbance to a uniform magnetic field induced by an immersed sphere. For a random distribution of particles, a linear relationship between the MRI signal decay rate (R-2(*)) and particle volume fraction (phi(v)) has previously been predicted in the MRI literature. This relationship was investigated for various types of particles suspended in agarose gel vials. Good agreement with theory was observed for particles with a high magnetic susceptibility difference from water. R-2(*) was also measured in a square channel flow containing a uniform distribution of titanium particles at two fully turbulent Reynolds numbers. Experimental results again agreed well with theory in the majority of the channel for both Reynolds numbers studied. Data from this flow were used to examine the expected SNR and dynamic range for MRP in future experiments. Some discrepancy was observed near the entry region of the channel, with possible explanations including inflowing fluid and large-scale flow structure effects behind the channel's mixing pin array. Finally, the new method was used to measure the 3D concentration distribution for a streak of titanium particles injected into a turbulent square channel flow with angled ribs. The transport of the streak was analyzed quantitatively, and a minor asymmetry in the channel geometry was shown to have important implications for the mean transport of the particle streak.