Below are items from the 45th DCASS, held 3 March 2020.
Medusa's Hair
Brian Bohan and Bennet Staton
Air Force Institute of Technology
Glowing 3D particle tracks from a reacting gas-turbine swirler pilot flame holder burning propane. A series of 50 image frames from a high-speed video were averaged together to see the particle paths.
One Vane, Two Vane, Red Vane, Blue Vane
Daniel Holobeny and Brian Bohan
Air Force Institute of Technology
Turbine nozzle guide vanes at the aft of a small gas turbine engine in a non-rotating configuration. This testing validated the operability of the new ultra compact combustor design.
Paradox
Travis Shelton
Air Force Institute of Technology
This is a scanning electron microscope (SEM) image of a metal 3D printed structure, known as a triply periodic minimal surface (TPMS). Organic in shape, a single minimal surface is characterized by its different curvatures; the featured surface curvature is commonly called a "gyroid". The gyroid is highly symmetrical while exhibiting periodicity independent in all three directions. The result is an efficient mechanical structure due to the periodic loading.
Phenomenal Cosmic Power...Itty Bitty Living Space
Bennet Stanton and Brian Bohan
Air Force Institute of Technology
A propane-air flame, seeded with glowing silicon carbide, was recorded at 10,000 frames per second as it anchored to a swirling jet pilot light. The inverted velocity recirculation at the center of the swirl resembles a genie being returned to its vessel.
Modeling of Staged Pressurized Oxy-fuel Combustion of a Multi-phase
Medium comprised of Methane (Fluid) and Pulverized Coal (Solid)
Alain Islas
West Virginia University
Aiming to support the experiments on SPOC ongoing at Washington University in St. Louis (WUSTL), our computational combustion group at West Virginia University (WVU) performs a numerical study of a lab-scale SPOC reactor by using the ANSYS Fluent software for steady and unsteady Reynolds-averaged Naiver-Stokes simulations (RANS) as well as large-eddy simulations (LES). The simulations consider the total power to be 100 kW, varying the inputs from coal and methane (CH4), with CO2 being the coal carrier. the numerical analysis involves a two-phase flow, turbulence, heat transfer as well as the flame and particle dynamics. The species transport model with the finite rate/eddy dissipation turbulence-chemistry interaction is used for coal combustion, along with a non-premixed combustion model for coal-CH4 burning.
Nanosecond-Pulsed High-Frequency Discharge Ignition Kernel Growth
Katherine Opacich and Joshua Heyne
University of Dayton
This video displays a nanosecond-pulsed high-frequency discharge ignition event and subsequent kernel growth. The video was generated by using high frame rate schlieren imaging plus the addition of a colored filter.