2 citations · 4 across the 9 of their papers we have counts for
9 papers
A High-Accuracy Symplectic Scheme for a nonlinear transport problem
Farjana Siddiqua, Catalin Trenchea
We analyze an advection-diffusion-reaction problem with non-homogeneous boundary conditions that models the chromatography process.We prove stability and error estimates for both c…
Data assimilation with model errors
Aytekin Çibik, Rui Fang, William Layton +1
Nudging is a data assimilation method amenable to both analysis and implementation. It also has the (reported) advantage of being insensitive to model errors compared to other assi…
Statistics in a Backscatter Eddy Viscosity Turbulence Model
Ali Pakzad, Farjana Siddiqua
This paper addresses two significant drawbacks of an eddy viscosity turbulence model: the issue of excessive dissipation relative to energy input and the lack of a universal parame…
Adaptive Parameter Selection in Nudging Based Data Assimilation
Aytekin Çıbık, Rui Fang, William Layton +1
Data assimilation combines (imperfect) knowledge of a flow's physical laws with (noisy, time-lagged, and otherwise imperfect) observations to produce a more accurate prediction of…
The Ramshaw-Mesina Hybrid Algorithm applied to the Navier Stokes Equations
Aytekin Çibik, Farjana Siddiqua, William Layton
In 1991, Ramshaw and Mesina proposed a novel synthesis of penalty methods and artificial compression methods. When the two were balanced they found the combination was 3-4 orders m…
Stability and Accuracy analysis of the Method and 3-Point Time filter
Nicholas Hurl, Farjana Siddiqua, Shuxian Xu
This paper analyzes a -method and 3-point time filter. This approach adds one additional line of code to the existing source code of -method. We prove the method's -stabil…
Variable Time Step Method of DAHLQUIST, LINIGER and NEVANLINNA (DLN) for a Corrected Smagorinsky Model
Farjana Siddiqua, Wenlong Pei
Turbulent flows strain resources, both memory and CPU speed. The DLN method has greater accuracy and allows larger time steps, requiring less memory and fewer FLOPS. The DLN method…
Numerical Analysis of a Corrected Smagorinsky Model
Farjana Siddiqua, Xihui Xie
The classical Smagorinsky model's solution is an approximation to a (resolved) mean velocity. Since it is an eddy viscosity model, it cannot represent a flow of energy from unresol…
A Modified Poisson--Nernst--Planck Model with Excluded Volume Effect: Theory and Numerical Implementation
Farjana Siddiqua, Zhongming Wang, Shenggao Zhou
The Poisson--Nernst--Planck (PNP) equations have been widely applied to describe ionic transport in ion channels, nanofluidic devices, and many electrochemical systems. Despite the…