Short student presentations
Pennsylvania State University
Student presentations
Jennifer Colborn
Department of Mechanical Engineering
Relative impact of convective and radiative heat transfer in a backward facing step combustor
Flow fields in gas turbine combustors have a wide variety of flow features near the combustor liner, including recirculation, shear layer separation and impingement, and boundary-layer development. As a result, modeling and predicting the heat transfer to the liner is challenging. The current work seeks to investigate the relative contributions of convective and radiative heat transfer to combustor liners using a backward-facing step combustor. Backward-facing step flows have many features relevant to gas turbines in a two-dimensional geometry, allowing for simpler modeling and easier instrumentation. Reynolds number, air temperature, and temperature of the combustor floor were varied to determine the impact of each parameter on the heat transfer through the different combustor zones: the recirculation, impingement, and recovery zones. Using a heat flux sensor and a radiometer, the total and radiative heat flux in these different zones was measured, respectively. Total heat flux was much higher than radiative heat flux, indicating the importance of convection heat transfer at these conditions. Increases in air and plate temperature increased both total and radiative heat transfer. Additionally, the highest heat flux was observed in the impingement zone and the lowest heat transfer was usually observed in the recirculation zone.
Samuel Gosin
Department of Aerospace Engineering
Implementation of two local correlation-based transition models in the OVERFLOW overset grid CFD solver
Menter’s SST-based 1-equation transition model and an SA-based implementation of the Langtry–Menter γ–Reθ,t transition model has been implemented into NASA’s OVERFLOW 2.3e CFD solver. An initial assessment of the implemented models has been carried out using benchmark 2D test cases involving flat plates and the NLF-0416 airfoil, focusing on bypass, Tollmien–Schlichting wave, and laminar separation bubble-induced transition scenarios.
