Turbulent Plenum Jet-Crossflow Validation Via Subgrid Scale Model Variation And Upstream Forcing Under Dynamic Hybrid RANS-LES

Author

• Cole W. McCallumFollow

Date of Graduation

5-2026

Document Type

Thesis

Degree Name

Bachelor of Science in Mechanical Engineering

Degree Level

Undergraduate

Department

Mechanical Engineering

Advisor/Mentor

Dr. Keith Walters

Committee Member

Dr. Jim Leylek

Abstract

In modern gas turbine design, film cooling has become ubiquitous as a method for limiting heat transfer between high temperature gases post-combustion and the surface of downstream blades. This paper validates the use of various computational fluid dynamics techniques in recreating an experiment measuring adiabatic effectiveness over a surface downstream of a compound-angle N2 plenum jet incident on a turbulent-air boundary layer [1]. To do this, both RANS and Dynamic Hybrid RANS-LES (DHRL) methods are implemented and compared to previous research [2]. The latter method is then modified through implementation of a different subgrid scale (SGS) model and through addition of a statistically targeted synthetic turbulence forcing function upstream of the plenum inlet. Results are obtained for DHRL using the new SGS and forcing function and compared to experiment. It is found that at a high nitrogen-air blowing ratio, the addition of upstream synthetic turbulence has a negligible effect on adiabatic effectiveness, especially when compared to SGS model alteration. When at a lower blowing ratio, the comparative effect is more nuanced, with turbulence generation improving DHRL results by a noticeable amount compared to experiment.

Keywords

Film cooling; CFD; Hybrid RANS-LES; Subgrid Scale Model

Citation

McCallum, C. W. (2026). Turbulent Plenum Jet-Crossflow Validation Via Subgrid Scale Model Variation And Upstream Forcing Under Dynamic Hybrid RANS-LES. Mechanical Engineering Undergraduate Honors Theses Retrieved from https://scholarworks.uark.edu/meeguht/152