Jemcov, Aleksandar; Maruszewski, Joseph P; Cokljat, Davor; Choudhury, Dipankar Pressure Correction Solver Based on Preconditioned Numeric Flux for Incompressible and Compressible Flows Inproceedings 51st Aerospace Sciences Meeting, AIAA 2013. Abstract | Links | BibTeX | Tags: Compressible, Incompressible, Solver @inproceedings{jemcov2013pressure,
title = {Pressure Correction Solver Based on Preconditioned Numeric Flux for Incompressible and Compressible Flows},
author = { Aleksandar Jemcov and Joseph P Maruszewski and Davor Cokljat and Dipankar Choudhury},
doi = {10.2514/6.2013-1128 },
year = {2013},
date = {2013-01-01},
booktitle = {51st Aerospace Sciences Meeting},
organization = {AIAA},
abstract = {Pressure based solvers in collocated grid arrangement require additional dissipation term in order to prevent pressure-velocity decoupling. Typically the dissipation is added through an interpolation procedure for the face velocity. While the face velocity interpolation resolves problems related to odd-even decoupling, the resulting dissipation is somewhat larger than what is required for the solution stabilization leading to diffusive contact and shock interfaces. On the other hand, density based solvers are well known for their resolution of discontinuities. They are often used in conjunction with eigenvalue preconditioning in order to be applicable in the low Mach number and incompressible limits. Here we demonstrate how ideas from both pressure and density based solvers can be utilized to create an all speed pressure based solver with minimal dissipation. The main idea is to use density based framework to define dissipation terms while a pressure based solver is used for the overall solution algorithm and updates of primitive variables.},
keywords = {Compressible, Incompressible, Solver},
pubstate = {published},
tppubtype = {inproceedings}
}
Pressure based solvers in collocated grid arrangement require additional dissipation term in order to prevent pressure-velocity decoupling. Typically the dissipation is added through an interpolation procedure for the face velocity. While the face velocity interpolation resolves problems related to odd-even decoupling, the resulting dissipation is somewhat larger than what is required for the solution stabilization leading to diffusive contact and shock interfaces. On the other hand, density based solvers are well known for their resolution of discontinuities. They are often used in conjunction with eigenvalue preconditioning in order to be applicable in the low Mach number and incompressible limits. Here we demonstrate how ideas from both pressure and density based solvers can be utilized to create an all speed pressure based solver with minimal dissipation. The main idea is to use density based framework to define dissipation terms while a pressure based solver is used for the overall solution algorithm and updates of primitive variables. |

Jemcov, ALeksandar; Mathur, Sanjay Nonlinear Parameter Estimation in Inviscid Compressible Flows in Presence of Uncertainties Conference CFD2005 Conference CFD Society of Canada, CFD Society of Canada 2005. Abstract | Links | BibTeX | Tags: AEM, Algorithm, C++, Compressible, Flow, SEM, Velocity @conference{jemcov2005nonlinear,
title = {Nonlinear Parameter Estimation in Inviscid Compressible Flows in Presence of Uncertainties},
author = { ALeksandar Jemcov and Sanjay Mathur},
url = {https://www.researchgate.net/profile/Aleksandar_Jemcov/publication/265161046_NONLINEAR_PARAMETER_ESTIMATION_IN_INVISCID_COMPRESSIBLE_FLOWS_IN_PRESENCE_OF_UNCERTAINTIES/links/54009fa20cf2c48563ae5881.pdf?origin=publication_detail_rebranded&ev=pub_int_prw_xdl&msrp=Eb6hxD11VAw8qlL87p7OgqEvootFE1qcP1%2B29eaQTXDZQJsA8p7cxhtWYujmiizIS6g9Ghe%2Fs%2FiKlYpqUkiuGg%3D%3D_xyhmRLK3POGJnefHrNX7GIlJ13cJFypuToDg6Wh3WROQGJDU9efiaEfVb4Ncmlvxom8DUrMXvQfMj5PjopEZKw%3D%3D&inViewer=1},
year = {2005},
date = {2005-01-01},
booktitle = {CFD2005 Conference CFD Society of Canada},
organization = {CFD Society of Canada},
abstract = {The focus of this paper is on the formulation and solution of inverse problems of parameter estimation using algorithmic differentiation. The inverse problem formulated here seeks to determine the input parameters that minimize a least squares functional with respect to certain target data. The formulation allows for uncertainty in the target data by considering the least squares functional in a stochastic basis described by the covariance
of the target data. Furthermore, to allow for robust design, the formulation also accounts for uncertainties in the input parameters. This is achieved using the method of propagation of uncertainties using the directional derivatives of the output parameters with respect to unknown parameters. The required derivatives are calculated simultaneously with the solution using generic programming exploiting the template
and operator overloading features of the C++ language. The methodology described here is general and applicable to any numerical solution procedure for any set of governing equations but for the purpose of this paper we consider a finite volume solution of the compressible Euler equations. In particular, we illustrate the method for the case of supersonic flow in a duct with a wedge. The parameter to be determined is the
inlet Mach number and the target data is the axial component of velocity at the exit of the duct.},
keywords = {AEM, Algorithm, C++, Compressible, Flow, SEM, Velocity},
pubstate = {published},
tppubtype = {conference}
}
The focus of this paper is on the formulation and solution of inverse problems of parameter estimation using algorithmic differentiation. The inverse problem formulated here seeks to determine the input parameters that minimize a least squares functional with respect to certain target data. The formulation allows for uncertainty in the target data by considering the least squares functional in a stochastic basis described by the covariance
of the target data. Furthermore, to allow for robust design, the formulation also accounts for uncertainties in the input parameters. This is achieved using the method of propagation of uncertainties using the directional derivatives of the output parameters with respect to unknown parameters. The required derivatives are calculated simultaneously with the solution using generic programming exploiting the template
and operator overloading features of the C++ language. The methodology described here is general and applicable to any numerical solution procedure for any set of governing equations but for the purpose of this paper we consider a finite volume solution of the compressible Euler equations. In particular, we illustrate the method for the case of supersonic flow in a duct with a wedge. The parameter to be determined is the
inlet Mach number and the target data is the axial component of velocity at the exit of the duct. |