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Data-Driven RANS Turbulence Closures for Forced Convection Flow in Reactor Downcomer Geometry

Journal Article · · Nuclear Technology

Recent progress in data-driven turbulence modeling has shown its potential to enhance or replace traditional equation-based Reynolds-averaged Navier-Stokes (RANS) turbulence models. Here, this work utilizes invariant neural network (NN) architectures to model Reynolds stresses and turbulent heat fluxes in forced convection flows (when the models can be decoupled). As the considered flow is statistically one dimensional, the invariant NN architecture for the Reynolds stress model reduces to the linear eddy viscosity model. To develop the data-driven models, direct numerical and RANS simulations in vertical planar channel geometry mimicking a part of the reactor downcomer are performed. Different conditions and fluids relevant to advanced reactors (sodium, lead, unitary-Prandtl-number fluid, and molten salt) constitute the training database. The models enabled accurate predictions of velocity and temperature, and compared to the baseline k–τ turbulence model with the simple gradient diffusion hypothesis, do not require tuning of the turbulent Prandtl number. The data-driven framework is implemented in the open-source graphics processing unit–accelerated spectral element solver nekRS and has shown the potential for future developments and consideration of more complex mixed convection flows.

Research Organization:
Argonne National Laboratory (ANL), Argonne, IL (United States)
Sponsoring Organization:
USDOE Office of Nuclear Energy (NE), Nuclear Energy Advanced Modeling and Simulation (NEAMS)
Grant/Contract Number:
AC02-06CH11357
OSTI ID:
2404550
Journal Information:
Nuclear Technology, Journal Name: Nuclear Technology Journal Issue: 7 Vol. 210; ISSN 0029-5450
Publisher:
Taylor & FrancisCopyright Statement
Country of Publication:
United States
Language:
English

References (30)

The numerical computation of turbulent flows journal March 1974
Remarks on turbulent constitutive relations journal July 1993
On the generality of tensor basis neural networks for turbulent scalar flux modeling journal November 2021
Reynolds-averaged stress and scalar-flux closures via symbolic regression for vertical natural convection journal August 2022
Machine-learning for turbulence and heat-flux model development: A review of challenges associated with distinct physical phenomena and progress to date journal June 2022
A CFD four parameter heat transfer turbulence model for engineering applications in heavy liquid metals journal February 2014
Data-driven scalar-flux model development with application to jet in cross flow journal February 2020
Towards robust and accurate Reynolds-averaged closures for natural convection via multi-objective CFD-driven machine learning journal May 2022
Physics-constrained machine learning for thermal turbulence modelling at low Prandtl numbers journal September 2022
A robust and accurate outflow boundary condition for incompressible flow simulations on severely-truncated unbounded domains journal March 2014
A paradigm for data-driven predictive modeling using field inversion and machine learning journal January 2016
Machine learning strategies for systems with invariance properties journal August 2016
Quantifying model form uncertainty in Reynolds-averaged turbulence models with Bayesian deep neural networks journal April 2019
SAM-ML: Integrating data-driven closure with nuclear system code SAM for improved modeling capability journal December 2022
Quantification of model uncertainty in RANS simulations: A review journal July 2019
Turbulent Flows book July 2012
A more general effective-viscosity hypothesis journal November 1975
Reynolds averaged turbulence modelling using deep neural networks with embedded invariance journal October 2016
Turbulent scalar flux in inclined jets in crossflow: counter gradient transport and deep learning modelling journal November 2020
Physics-informed machine learning journal May 2021
Learning nonlinear operators via DeepONet based on the universal approximation theorem of operators journal March 2021
Direct Numerical Simulation of Low and Unitary Prandtl Number Fluids in Reactor Downcomer Geometry journal June 2023
Toward Improved Correlations for Mixed Convection in the Downcomer of Molten Salt Reactors journal July 2023
A Perspective on Data-Driven Coarse Grid Modeling for System Level Thermal Hydraulics journal September 2022
Perspectives on machine learning-augmented Reynolds-averaged and large eddy simulation models of turbulence journal May 2021
Theory of Representations for Tensor Functions—A Unified Invariant Approach to Constitutive Equations journal November 1994
Development and Use of Machine-Learnt Algebraic Reynolds Stress Models for Enhanced Prediction of Wake Mixing in Low-Pressure Turbines journal March 2019
Turbulence Modeling in the Age of Data journal January 2019
Application of a new K-tau model to near wall turbulent flows journal February 1992
Development of Machine Learning Models for Turbulent Wall Pressure Fluctuations conference January 2017