ID 154

Characterizing the Near-Field Region of a Spray using White Beam and Focus Beam X-ray Measurements

 

Abstract:

A current challenge being investigated is controlling sprays using real time feedback. In working towards this goal, it is necessary to create a reduced-order model of the spray. The model will then be used to determine the best method of monitoring the spray and provide an estimate of the resulting change from the controlling mechanism. The current work focuses on characterizing the near-field region of a co-axial airblast atomizer; these data will eventually be used to formulate a data-driven model for spray control. High-speed white beam and focused beam X-ray imaging of the near-field region of the atomizer has been recorded at the Advanced Photon Source at Argonne National Laboratory. Time resolved measurements have shown that there is a natural harmonic in the instabilities of the near-filed region. Liquid ligaments and internal air bubbles are observed near the nozzle tip in a region that was previously thought to be a continuous liquid region. The location of primary atomization has been determined through the X-ray measurements and was determined to vary with gas momentum ratio and fluid mass ratio. Swirl has been added to the air stream of the atomizer and has been shown to change the location of primary atomization as well as the shape of the jet. Future work will combine the current data with those obtained in the far-field region to create a reduced-order model for spray control.