Abstract
This work examines the temporal dynamics in the near-field of a low aspect ratio mixing layer. Using Planar Laser Induced-Fluorescence (PLIF), we investigate mixing dynamics between a rhodamine dye contaminated stream and a clean water uncontaminated stream at different velocity ratios. An in-situ calibration experiment is performed to verify the linearity of the image intensity with rhodamine concentration and to account for spatial variations in laser sheet intensity. The mixing dynamics are analyzed for velocity ratios ranging from one to three, defined as the ratio between the bulk velocity in the small channel to the bulk velocity in the large channel. This range yields mixing layer Reynolds numbers based on the velocity difference, channel width, and kinematic viscosity of water ranging from zero to approximately 1,600. The average and transient properties of the mixing layer are analyzed. The average concentration distribution is presented to quantify the spreading rate of the mixing layer. Of particular interest is the intermittency of the concentration time series at the channel centerline and the nominally clean and contaminated streams, both of which are related to the formation of large scale vortical structures.
| Original language | English |
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| Title of host publication | Fluids Engineering; Heat Transfer and Thermal Engineering |
| Publisher | American Society of Mechanical Engineers (ASME) |
| ISBN (Electronic) | 9780791886700 |
| DOIs | |
| State | Published - 2022 |
| Event | ASME 2022 International Mechanical Engineering Congress and Exposition, IMECE 2022 - Columbus, United States Duration: Oct 30 2022 → Nov 3 2022 |
Publication series
| Name | ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE) |
|---|---|
| Volume | 8 |
Conference
| Conference | ASME 2022 International Mechanical Engineering Congress and Exposition, IMECE 2022 |
|---|---|
| Country/Territory | United States |
| City | Columbus |
| Period | 10/30/22 → 11/3/22 |
Funding
The authors would like to acknowledge the Department of Physics and Nuclear Engineering, and the Photonics Research Center at the United States Military for the use of their technology. The views expressed herein are those of the authors and do not proport to reflect the position of the United States Military Academy, the Department of the Army, or the Department of Defense.