Electronic Theses and Dissertations

Identifier

6764

Date

2021

Document Type

Thesis

Degree Name

Master of Science

Major

Mechanical Engineering

Abstract

Developing a model for the collision rate constant between a dust grain and an ion in a high ion concentration system is essential to estimate/calculate the electric charge of a grain in a plasma. The particle is negatively charged due to higher mobility of electrons in the plasma than with ions that are positively charged. The non-dimensional collision rate constant H of the dust particle and ion are calculated using Langevin Dynamics trajectory simulations. The trajectories are calculated using a first order time stepping scheme to solve the Langevin equation of motion for the ions. To account for ion neutral collisions, H is calculated over a wide range of 𝑲𝒏𝑫, the diffusive Knudsen number, from the free molecular or low-pressure regime (KnD→∞) to the continuum or high-pressure regime (KnD→0). To account for the ion-grain electrostatic interaction parameterized by ψE , H is calculated over a range of 𝝍𝑬 that varies between 0 to 300. To account for concentration of the ions within the domain and temperature of the gas, H will be calculated over a range of 0.01≤ χ ≤10 and 0< Γig ≤30. This will be the first model of the dust particle ion collision rate constant that accounts for ion-ion interactionism, in addition to the ion-particle and ion-neutral gas interactions, as opposed to existing ones that account for the latter two effects only. H will be compared to such previous models to quantitatively establish the effect of ion-ion interactions and motivate future experimental validation, as currently no experimental data exists to validate the model for 𝐻. In the future, we hope this model will be validated with experimental results. This thesis will give results for 0.01 ≤ χ ≤ 1 at Γig=1.5

Comments

Data is provided by the student.Title, statement of responsibility, and other descriptive elements, and key words are machine generated from author's electronic form submitted to the Graduate School, University of Memphis.

Library Comment

Title, statement of responsibility, and other descriptive elements, and key words are machine generated from author's electronic form submitted to the Graduate School, University of Memphis.

Notes

Open Access

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