A Finite-Volume based POD-Galerkin reduced order modeling strategy for steady-state Reynolds averaged Navierâ€“Stokes (RANS) simulation is extended for low-Prandtl number flow. The reduced order model is based on a full order model for which the effects of buoyancy on the flow and heat transfer are characterized by varying the Richardson number. The Reynolds stresses are computed with a linear eddy viscosity model. A single gradient diffusion hypothesis, together with a local correlation for the evaluation of the turbulent Prandtl number, is used to model the turbulent heat fluxes. The contribution of the eddy viscosity and turbulent thermal diffusivity fields are considered in the reduced order model with an interpolation based data-driven method. The reduced order model is tested for buoyancy-aided turbulent liquid sodium flow over a vertical backward-facing step with a uniform heat flux applied on the wall downstream of the step. The wall heat flux is incorporated with a Neumann boundary condition in both the full order model and the reduced order model. The velocity and temperature profiles predicted with the reduced order model for the same and new Richardson numbers inside the range of parameter values are in good agreement with the RANS simulations. Also, the local Stanton number and skin friction distribution at the heated wall are qualitatively well captured. Finally, the reduced order simulations, performed on a single core, are about 105 times faster than the RANS simulations that are performed on eight cores.

VL - 89 ER - TY - JOUR T1 - Reduced order models for the incompressible Navier-Stokes equations on collocated grids using a `discretize-then-project' approach JF - International Journal for Numerical Methods in Fluids Y1 - 2021 A1 - Kelbij Star A1 - Benjamin Sanderse A1 - Giovanni Stabile A1 - Gianluigi Rozza A1 - Joris Degroote PB - Wiley VL - 93 UR - https://doi.org/10.1002/fld.4994 ER - TY - CONF T1 - POD-Galerkin Reduced Order Model of the Boussinesq Approximation for Buoyancy-Driven Enclosed Flows T2 - International Conference on Mathematics and Computational Methods Applied to Nuclear Science and Engineering, M and C 2019 Y1 - 2019 A1 - Kelbij Star A1 - Giovanni Stabile A1 - Sokratia Georgaka A1 - Francesco Belloni A1 - Gianluigi Rozza A1 - Joris Degroote JF - International Conference on Mathematics and Computational Methods Applied to Nuclear Science and Engineering, M and C 2019 SN - 9780894487699 ER -