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Computational solution verification applied to a thermal model of a ruggedized instrumentation package

WIT Transactions on Modelling and Simulation

Scott, S.N.; Templeton, Jeremy A.; Ruthruff, Joseph R.; Hough, Patricia D.; Peterson, Jerrod P.

This paper details a methodology for quantification of errors and uncertainties of a finite element heat transfer model applied to a Ruggedized Instrumentation Package (RIP). The proposed verification process includes solution verification, which examines the errors associated with the code's solution techniques. The model was subjected to mesh resolution and numerical parameters sensitivity studies to determine reasonable parameter values and to understand how they change the overall model response and performance criteria. To facilitate quantification of the uncertainty associated with the mesh, automatic meshing and mesh refining/coarsening algorithms were created and implemented on the complex geometry of the RIP. Similarly, highly automated software to vary model inputs was also developed for the purpose of assessing the solution's sensitivity to numerical parameters. The model was subjected to mesh resolution and numerical parameters sensitivity studies. This process not only tests the robustness of the numerical parameters, but also allows for the optimization of robustness and numerical error with computation time. Agglomeration of these studies provides a bound for the uncertainty due to numerical error for the model. An emphasis is placed on the automation of solution verification to allow a rigorous look at uncertainty to be performed even within a tight design and development schedule. © 2013 WIT Press.

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TYPE Conference YEAR 2013
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Comparison of molecular dynamics with classical density functional and Poisson-Boltzmann theories of the electric double layer in nanochannels

Journal of Chemical Theory and Computation

Lee, Jonathan W.; Nilson, Robert H.; Templeton, Jeremy A.; Griffiths, Stewart K.; Kung, Andy K.; Wong, Bryan M.

Comparisons are made among Molecular Dynamics (MD), Classical Density Functional Theory (c-DFT), and Poisson-Boltzmann (PB) modeling of the electric double layer (EDL) for the nonprimitive three component model (3CM) in which the two ion species and solvent molecules are all of finite size. Unlike previous comparisons between c-DFT and Monte Carlo (MC), the present 3CM incorporates Lennard-Jones interactions rather than hard-sphere and hard-wall repulsions. c-DFT and MD results are compared over normalized surface charges ranging from 0.2 to 1.75 and bulk ion concentrations from 10 mM to 1 M. Agreement between the two, assessed by electric surface potential and ion density profiles, is found to be quite good. Wall potentials predicted by PB begin to depart significantly from c-DFT and MD for charge densities exceeding 0.3. Successive layers are observed to charge in a sequential manner such that the solvent becomes fully excluded from each layer before the onset of the next layer. Ultimately, this layer filling phenomenon results in fluid structures, Debye lengths, and electric surface potentials vastly different from the classical PB predictions. © 2012 American Chemical Society.

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TYPE Journal Article YEAR 2012
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Results 51–75 of 93
Results 51–75 of 93