Session: 13-04 - Transients, Unsteadiness and Swirl

Paper Number: 127902

127902 - Investigation of Conjugate Heat Transfer in Wall-Modeled Large Eddy Simulation of High-Speed Compressible Wall-Bounded Flows 

Heat transfer has been shown to influence the behavior of turbulent wall-bounded flows in a variety of ways. For example Reynolds-stresses, coherent structures, and skin friction can be altered significantly in localized regions. Understanding and predicting the physical mechanisms underpinning these effects is critical to improving the design of cooling technologies. Conjugate Heat Transfer (CHT) is a methodology that models heat transfer in the adjacent solid domain and couples it to the fluid domain through a mutual set of thermal boundary conditions. This allows the wall thermal state to vary realistically in space and time. However, CHT also introduces extreme additional cost to numerical simulations due to large time-scale disparities between processes in the fluid and solid domains. Loosely-coupled methods seek to mitigate this cost for Large Eddy Simulation (LES) of high-speed compressible flows. Similarly, given the importance of treating boundary layer dynamics correctly with CHT, wall modeling makes LES more computationally tractable, but has not been widely used with CHT. In this work, a parameter study is performed in a compressible boundary-layer at supersonic conditions to investigate the combination of a previously validated loosely-coupled CHT methodology combined with advanced wall modeling approaches for LES. The wall-modeling and loosely coupled CHT methodology is found to yield similar results for orders of magnitude reduction in numerical cost. Additionally, the strength of the fluctuations of the solid wall, enforced through CHT, is found to have negligible influence on turbulence statistical quantities of interest such as Reynolds stresses, skin friction coefficient, and mean velocity profiles, indicating that the fluctuations of the solid wall are negligible in these cases.

Presenting Author: Julia Muller Georgia Institute of Technology

Presenting Author Biography: Julia Muller is a PhD student studying aerospace engineering at the Daniel Guggenheim School of Aerospace Engineering. Her thesis covers the effects of heat transfer on high speed turbulent flows, with specific focus on the shock boundary layer interaction (SBLI) phenomena and the unsteadiness mechanisms that govern the separation bubble's low frequency oscillatory motion. Additionally, she seeks to mitigate the extreme numerical cost the conjugate heat transfer (CHT) boundary condition introduces to LES and DNS. CHT is used in a variety of engineering applications to better model the effect of heat transfer from the solid domain on the fluid domain. Julia hopes to continue her career researching heat transfer effects on high speed turbulent boundary layers after graduate school, either in academia or at a national research lab. In her free time she enjoys painting, playing Dungeons and Dragons, and Brazilian jiu jitsu.

Authors:

Julia Muller Georgia Institute of Technology
Meghna Dutta Georgia Institute of Technology
Joshua Boisvert Georgia Institute of Technology
Joseph Oefelein Georgia Institute of Technology