Towards an intermolecular potential for nitrogen

Ling, Mercy S.H.; Rigby, Maurice

doi:10.1080/00268978400100571

Cited by 103 publications

(16 citation statements)

References 50 publications

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“…However, for vibrational relaxation at high energies, the accuracy of MD calculations becomes more sensitive to the PES where, in particular, the shape of the 'repulsive wall' becomes important. 9a, there is more than an order of magnitude discrepancy when using a LJ potential with a power law exponent of 12 versus using the Ling-Rigby Harmonic Oscillator (HO) potential [68] which has a more realistic exponential fit for the repulsive wall leading to close agreement with experiment and QCT results of Billing and Fisher. The results are shown in Fig.…”

Section: Molecular Dynamics and Trajectory-based Dsmcmentioning

confidence: 60%

Progress and future prospects for particle-based simulation of hypersonic flow

Schwartzentruber¹,

Boyd²

2015

Progress in Aerospace Sciences

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a b s t r a c tThe direct simulation Monte Carlo method (DSMC) has evolved over 50 years into a powerful numerical technique for the computation of thermochemical nonequilibrium gas flows. In this context, nonequilibrium means that velocity and internal energy distribution functions are not in equilibrium forms due to a low number of intermolecular collisions within a fluid element. In hypersonic flow, nonequilibrium conditions occur at high altitude and in regions of flow fields with small length scales. This article highlights significant developments in particle simulation methods (since 2001) applied specifically to hypersonic flows, which now includes Molecular Dynamics in addition to DSMC. Experimental measurements that have led directly to improved DSMC models will be highlighted. Algorithm development for DSMC aimed at increasing computational efficiency is discussed with a focus on hybrid particle-continuum methods. New research that applies all-atom Molecular Dynamics simulation and trajectory-based DSMC simulation to normal shock waves is summarized. Finally, a discussion of state-resolved DSMC modeling is included with reference to future prospects for particle simulation methods and in particular for the DSMC method. (I.D. Boyd).Please cite this article as: Schwartzentruber TE, Boyd ID. Progress and future prospects for particle-based simulation of hypersonic flow. Progress in Aerospace Sciences (2014), http://dx.Progress in Aerospace Sciences ∎ (∎∎∎∎) ∎∎∎-∎∎∎ Please cite this article as: Schwartzentruber TE, Boyd ID. Progress and future prospects for particle-based simulation of hypersonic flow. Progress in Aerospace Sciences (2014), http://dx.

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Section: Molecular Dynamics and Trajectory-based Dsmcmentioning

confidence: 60%

Progress and future prospects for particle-based simulation of hypersonic flow

Schwartzentruber¹,

Boyd²

2015

Progress in Aerospace Sciences

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“…We note that the computed profiles of nitrogen pairs are based on the isotropic interaction potential of Ling and Rigby [20]; those of methane are based on the Reid et al potential [21]. Matrix elements were computed for all free-free, boundfree and bound-bound transitions.…”

Section: Theoretical Line Profilesmentioning

confidence: 99%

About an information theoretical spectral line shape proposed for the collision induced spectroscopies

1987

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“…[15][16][17][18][19][20] Trajectory calculations (often referred to as quasiclassical due to the quantum mechanical nature of the PES) can then be done on a pre-computed PES and kinetic theory collision integrals for rotational relaxation and transport properties can be evaluated using a Monte Carlo technique. Nyeland and Billing 21 compute N 2 -N 2 classical trajectories to solve collision integrals from the Wang Chang-Uhlenbeck theory.…”

Section: Introductionmentioning

confidence: 99%

Investigation of Rotational Relaxation in Nitrogen Via Molecular Dynamics Simulation

Valentini¹,

Zhang

Schwartzentruber³

2012

43rd AIAA Thermophysics Conference

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The objective of this study is to use Molecular Dynamics simulation to evaluate the rotational relaxation process in nitrogen from a first-principles perspective. The intermolecular model used in the MD simulations is shown to (i) reproduce very well the shear viscosity of nitrogen over a wide range of temperatures, (ii) predict the near-equilibrium rotational collision number in good agreement with published trajectory calculations done on ab initio Potential Energy Surfaces, and (iii) produce shock wave profiles in excellent accordance with the experimental measurements. The rotational relaxation process is found to be dependent not only on the near-equilibrium temperature (i.e., when systems relax to equilibrium after a small perturbation), but more importantly on both the magnitude and direction of the initial deviation from the equilibrium state. Although this dependence has been previously recognized, it is here investigated systematically. The comparison between MD and DSMC, based on the Larsen-Borgnakke model, for shock waves (both at low and high temperatures) and one-dimensional expansions shows that a judicious choice of a constant Zrot can produce DSMC results which are in relatively good agreement with MD. However, the selection of the rotational collision number is case-specific, depending not only on the temperature range, but more importantly on the type of flow (compression or expansion), with significant limitations for more complex simulations characterized both by expansion and compression zones. Parker's model, parametrized for nitrogen, overpredicts the magnitude of Zrot for temperatures above about 300 K. It is also unable to describe the dependence of the relaxation process on the direction to equilibrium. Finally, based on the MD data, a preliminary formulation for a novel rotational relaxation model, which includes a dependence on both the rotational and the translational state of the gas, is presented.

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Towards an intermolecular potential for nitrogen

Cited by 103 publications

References 50 publications

Progress and future prospects for particle-based simulation of hypersonic flow

Progress and future prospects for particle-based simulation of hypersonic flow

About an information theoretical spectral line shape proposed for the collision induced spectroscopies

Investigation of Rotational Relaxation in Nitrogen Via Molecular Dynamics Simulation

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