[HTML][HTML] Modal laminar–turbulent transition delay by means of topology optimization of superhydrophobic surfaces
When submerged under a liquid, the microstructure of a SuperHydrophobic Surface (SHS)
traps a lubricating layer of gas pockets, which has been seen to reduce the skin friction of …
traps a lubricating layer of gas pockets, which has been seen to reduce the skin friction of …
Sensitivity analysis on chaotic dynamical systems by finite difference non-intrusive least squares shadowing (FD-NILSS)
Abstract We present the Finite Difference Non-Intrusive Least Squares Shadowing (FD-
NILSS) algorithm for computing sensitivities of long-time averaged quantities in chaotic …
NILSS) algorithm for computing sensitivities of long-time averaged quantities in chaotic …
Approximating linear response by nonintrusive shadowing algorithms
A Ni - SIAM Journal on Numerical Analysis, 2021 - SIAM
Nonintrusive shadowing algorithms efficiently compute v, the difference between shadowing
trajectories, and then use v to compute derivatives of averaged objectives of chaos with …
trajectories, and then use v to compute derivatives of averaged objectives of chaos with …
Fast linear response algorithm for differentiating chaos
A Ni - arXiv preprint arXiv:2009.00595, 2020 - arxiv.org
We devise the fast linear response algorithm for differentiating fractal invariant measures of
chaos with respect to perturbations of governing equations. We first derive the first …
chaos with respect to perturbations of governing equations. We first derive the first …
Divide And Conquer: Learning Chaotic Dynamical Systems With Multistep Penalty Neural Ordinary Differential Equations
Forecasting high-dimensional dynamical systems is a fundamental challenge in various
fields, such as the geosciences and engineering. Neural Ordinary Differential Equations …
fields, such as the geosciences and engineering. Neural Ordinary Differential Equations …
Fast adjoint differentiation of chaos via computing unstable perturbations of transfer operators
A Ni - arXiv preprint arXiv:2111.07692, 2021 - arxiv.org
We devise the fast adjoint response algorithm for the gradient of physical measures (long-
time-average statistics) of discrete-time hyperbolic chaos with respect to many system …
time-average statistics) of discrete-time hyperbolic chaos with respect to many system …
Toward computing sensitivities of average quantities in turbulent flows
N Chandramoorthy, ZN Wang, Q Wang… - arXiv preprint arXiv …, 2019 - arxiv.org
Chaotic dynamical systems such as turbulent flows are characterized by an exponential
divergence of infinitesimal perturbations to initial conditions. Therefore, conventional …
divergence of infinitesimal perturbations to initial conditions. Therefore, conventional …
Adjoint Sensitivities of Chaotic Flows Without Adjoint Solvers: A Data-Driven Approach
In one calculation, adjoint sensitivity analysis provides the gradient of a quantity of interest
with respect to all system's parameters. Conventionally, adjoint solvers need to be …
with respect to all system's parameters. Conventionally, adjoint solvers need to be …
[图书][B] Numerical Differentiation of Stationary Measures of Chaos
A Ni - 2021 - search.proquest.com
In this thesis we develop two algorithms, the non-intrusive shadowing and the fast linear
response algorithms, for computing derivatives of SRB measures with respect to some …
response algorithms, for computing derivatives of SRB measures with respect to some …
Lyapunov spectrum of separated flows and its dependence on numerical discretization
P Fernandez, Q Wang - arXiv preprint arXiv:1612.07409, 2016 - arxiv.org
We investigate the Lyapunov spectrum of separated flows and their dependence on the
numerical discretization. The chaotic flow around the NACA 0012 airfoil at low Reynolds …
numerical discretization. The chaotic flow around the NACA 0012 airfoil at low Reynolds …