Detailed Validation of Numerical Simulations of Air-blast Spray Atomization against Experimental Back-lit Images and Radiographs
Sprays appear in a variety of industrial applications ranging from powder production used in additive manufacturing to fuel nozzles. Air-blast atomization is a specific injection strategy whereby a high-speed gas shears and destabilizes a low-speed liquid which causes a cascade of instabilities leading to the creation of a spray. The flow physics around the nozzle are challenging to quantify and complex. Inside the nozzle, traditional PIV and hot-wire methods cannot be used to measure turbulence and boundary layer growth and at the nozzle exit, radiographs and back-lit images show complex time-varying wetting and contact line dynamics. In this study, we explore different computational strategies to model these flow physics and validate them against equivalent path length data (EPL), a measure of the liquid depth along a line-of-sight. Further downstream, thin liquid structures that fall below the mesh size are prone to numerical break-up and as a consequence, we employ a thin-film model to improve agreement. We make use of a multi-block simulation strategy to address the multi-scale nature of atomization. Finally, using these models, we make direct comparisons of quantities such as the liquid intact length.
This conference proceeding is published as Vu, Lam, Nathanaël Machicoane, Danyu Li, Timothy Morgan, Theodore J. Heindel, Alberto Aliseda, and Olivier Desjardins. "Detailed Validation of Numerical Simulations of Air-blast Spray Atomization against Experimental Back-lit Images and Radiographs." 15th Triennial International Conference on Liquid Atomization and Spray Systems (ICLASS 2021), August 29-September 2, 2021. Posted with permission.