ID 129

Magnetic Resonance Imaging as a diagnostic technique for spray studies

 

Abstract:

Magnetic Resonance Imaging (MRI) is a non-invasive, three-dimensional imaging technique capable of measuring optically opaque media. The MR signal is directly proportional to the sample density, making the technique most sensitive for the liquid inside the nozzle and in the near-nozzle regions. These are also regions which represent a significant challenge for the most common methods used in spray characterization. We have recently demonstrated the potential of MRI for spray studies [1]. Density and velocity mapping can be performed for water inside ceramic nozzles with a sub-mm resolution. High spray speeds in the near-nozzle region necessitate development of magnetization preparation techniques to sensitize nuclear magnetization to parameters of interest [2]. In this work, density, velocity and diffusion/dispersion maps both inside and outside the nozzle will be presented. Considerable measurement challenges involve a trade-off between a high spatial resolution and time-of-flight effects caused by sample’s high speeds; sensitivity to presence of metal and how it can be possibly circumvented; MRI instrumentation hardware requirements. The limitations and potential new developments will be discussed. 1. I.V. Mastikhin, A. Arbabi, K.M. Bade. Magnetic Resonance Imaging measurements of a water spray upstream and downstream of a spray nozzle exit orifice. J.Magn.Reson. 266 (2016) 8-15. 2. I.V.Mastikhin, K.M. Bade, S.Ahmadi. A rapid magnetization preparation for MRI measurements of sprays. J.Magn.Reson. 283 (2017) 52-60.