Molecular dynamics simulations phd thesis

Molecular dynamics simulations phd thesis

MOLECULAR DYNAMICS SIMULATION OF MONTMORILLONITE AND MECHANICAL AND THERMODYNAMIC PROPERTIES CALCULATIONS A Thesis by SELMA AT ĐLHAN Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE May Major Subject: Chemical Engineering MOLECULAR DYNAMICS SIMULATION OF MONTMORILLONITE AND MECHANICAL AND THERMODYNAMIC PROPERTIES CALCULATIONS A Thesis by SELMA AT ĐLHAN Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE May Major Subject: Chemical Engineering In this thesis, we present a methodology for deriving a modified Reynolds equation (referred to as the Molecular Dynamics-based Equation for Lubrication, or the MODEL) which overcomes these limitations by introducing a Molecular Dynamics-based constitutive relationship for the flow rate through the lubrication gap, that is valid beyond the

Master thesis on the molecular dynamics simulations of intrinsically

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Some features of this site may not work without it. Toggle navigation. Molecular dynamics-based approaches for mesoscale lubrication Author s Chandramoorthy, Nisha, molecular dynamics simulations phd thesis. Download Full printable version Other Contributors Massachusetts Institute of Technology.

Computation for Design and Optimization Program. Advisor Nicolas G. Terms of use MIT theses are protected by copyright, molecular dynamics simulations phd thesis. They may be viewed, downloaded, or printed from this source but further reproduction or distribution in any format is prohibited without written permission.

Metadata Show full item record. Abstract Classical lubrication theory is unable to describe nanoscale flows due to the failure of two of its constitutive components: a the Newtonian stress-strain rate relationship and b the no-slip boundary condition. In this thesis, we present a methodology for deriving a modified Reynolds equation referred to as the Molecular Dynamics-based Equation for Lubrication, or the MODEL which overcomes these limitations by introducing a Molecular Dynamics-based constitutive relationship for the flow rate molecular dynamics simulations phd thesis the lubrication gap, that is valid beyond the range of validity of the Navier-Stokes constitutive models.

We demonstrate the proposed methodology for the flow of a simple lubricant, n-hexadecane, between smooth Iron walls and show that the MODEL is able to predict flow rates with good accuracy even in nanochannels that are only a few atomic layers wide. The MODEL constitutive relationship for the flow rate used in this work is a slip-corrected Poiseuille model with the slip length and viscosity derived from Molecular Dynamics MD simulations of pressure-driven flow in nanochannels sufficiently large that the Navier-Stokes description is valid.

Although more general expressions for the flow rate can certainly be used, for the lubricant-solid system modeled here, the slip-corrected Poiseuille flow was surprisingly found to be sufficient.

We validate the MODEL by comparing MD results for the pressure distribution in a barrel-drop lubrication configuration with the analytical solution for the pressure obtained by solving the MODEL.

The excellent agreement obtained between the dynamic pressure in the fluid measured from these MD simulations and the MODEL results suggests that it is possible to extend pde-based hydrodynamic modelling of lubrication problems even to nanoscale films beyond the validity of the Navier-Stokes description.

In other words, once the flow rate constitutive relation is obtained, lubrication problems in nanoscale films can be solved without resorting to expensive particle methods like MD. We demonstrate that slip molecular dynamics simulations phd thesis be neglected in the boundary lubrication regime by considering various lubrication problems of practical interest.

Using a simple barrel-drop lubrication model for the top two rings in an internal combustion engine, we show that for lubrication gaps with a minimum thickness that is ten times the size of the slip length, the normal force and the frictional force are overestimated by a factor of 1. By modifying the Twin Land Oil Control Ring TLOCR -liner interface model to include slip, molecular dynamics simulations phd thesis find significant reduction in the hydrodynamic pressure and the friction when compared to the original model; the oil flow rate does not change appreciably.

Finally, we chalk out a procedure for the inclusion of slip in the methodology for developing correlations for the pressure, friction and the flow rate in the TLOCR-liner system. Description Thesis: S, molecular dynamics simulations phd thesis. Date issued Department Massachusetts Institute of Technology. Publisher Massachusetts Institute of Technology.

Keywords Computation for Design and Optimization Program. Collections Graduate Theses. Search DSpace. This Collection. OA Statistics Statistics by Country Statistics by Department.

Basics of Molecular Dynamics Simulations

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Molecular dynamics-based approaches for mesoscale lubrication

MOLECULAR DYNAMICS SIMULATION OF MONTMORILLONITE AND MECHANICAL AND THERMODYNAMIC PROPERTIES CALCULATIONS A Thesis by SELMA AT ĐLHAN Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE May Major Subject: Chemical Engineering A Molecular Dynamics Simulation-Isothermal Titration Calorimetry Study of Antimicrobial Peptide-Peptide Interaction by Shaghayegh Vafaei A Thesis presented to The University of Guelph In partial fulfilment of requirements for the degree of Doctor of Philosophy in Biophysics Guelph, Ontario, Canada c Shaghayegh Vafaei, January, May 07,  · In the study presented in this thesis, we instead used a classical mechanics approach for computational simulations by performing molecular dynamics (MD) simulations. The approach is well-established and began in the s. Recently, the Nobel Prize in Chemistry was awarded to Martin Karplus, Michael Levitt, and Arieh