Efficient, Accurate, and Robust Penalty-Projection Algorithm for Parameterized Stochastic Navier-Stokes Flow Problems
Neethu Suma Raveendran, Md. Abdul Aziz, Sivaguru S. Ravindran, Muhammad Mohebujjaman
TL;DR
This work addresses uncertainty quantification for parameterized stochastic Navier–Stokes equations in convection-dominated regimes by introducing a fast, robust penalty-projection ensemble framework with grad-div stabilization and ensemble-eddy viscosity (EEV). The Coupled-EEV and the decoupled SPP-EEV schemes share the same system matrix across realizations, enabling efficient fully discrete solves; the SPP-EEV variant is shown to be unconditionally stable and to converge to the Coupled-EEV as the grad-div parameter $\gamma$ increases. The authors couple these time-stepping schemes with stochastic collocation methods on sparse grids, forming SCM-SPP-EEV and SCM-Coupled-EEV to achieve accurate UQ with reduced computational cost. Numerical experiments on Taylor Green–vortex, channel flow over a step, and regularized lid-driven cavity with five-dimensional random viscosity demonstrate optimal spatial and temporal convergence, strong agreement between SCM-SPP-EEV and SCM-Coupled-EEV, and clear advantages of EEV in convection-dominated flows. The results indicate a practical, scalable approach for UQ in complex fluid systems, with potential impact on simulations in engineering and geophysics where high Reynolds numbers and uncertain parameters are common.
Abstract
This paper presents and analyzes a fast, robust, efficient, and optimally accurate fully discrete splitting algorithm for the Uncertainty Quantification (UQ) of parameterized Stochastic Navier-Stokes Equations (SNSEs) flow problems those occur in the convection-dominated regimes. The time-stepping algorithm is an implicit backward-Euler linearized method, grad-div and Ensemble Eddy Viscosity (EEV) regularized, and split using discrete Hodge decomposition. Additionally, the scheme's sub-problems are all designed to have different Right-Hand-Side (RHS) vectors but the same system matrix for all realizations at each time-step. The stability of the algorithm is rigorously proven, and it has been shown that appropriately large grad-div stabilization parameters vanish the splitting error. The proposed UQ algorithm is then combined with the Stochastic Collocation Methods (SCMs). Several numerical experiments are given to verify this superior scheme's predicted convergence rates and performance on benchmark problems for high expected Reynolds numbers ($Re$).
