Analysis of gas-solid multiphase flow systems in extreme flight environments using a one-way coupled DSMC-Lagrangian overlay-based computational framework

Myers, Nathan K.

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https://hdl.handle.net/2142/125598 Copy

Description

Title

Analysis of gas-solid multiphase flow systems in extreme flight environments using a one-way coupled DSMC-Lagrangian overlay-based computational framework

Author(s)

Myers, Nathan K.

Issue Date

2024-07-16

Director of Research (if dissertation) or Advisor (if thesis)

Levin, Deborah A

Department of Study

Aerospace Engineering

Discipline

Aerospace Engineering

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

dilute multiphase flow, rarefied gas-particulate flow, irregular particle drag, DSMC, Lagrangian, one-way coupled

Abstract

This thesis presents a one-way coupled DSMC-Lagrangian overlay-based computational methodology designed to investigate the dynamics of gas-solid multiphase flow systems characterized by very low particulate mass loading in extreme high-speed, high-altitude flight environments. Utilizing the Direct Simulation Monte Carlo method to generate accurate steady-state gas flow fields, this study explores three canonical hypersonic flow systems. First, we focus on the dynamics of particulates within shock-dominated flow systems over axisymmetric sharp cone and sphere-cone geometries. In the flows over the sharp cone we analyze particulate behavior in systems characterized by attached oblique shocks, finding that the presence of a strong shear layer is primarily responsible for dictating the behavior of small particulates. This layer divides particulates by generating oppositely directed radial aerodynamic forces on either side of the layer. For small particulates within its vicinity, the shear layer acts to focus particulates into highly concentrated regions on the top or bottom of the layer depending on particulate diameter. For flows over the sphere-cone, we describe the particulate interaction with the detached bow shocks, ultimately revealing the formation of dust-free zones for small particulate diameters. As particulate diameter and flight altitude increase, the characteristics of the solid phase flow evolve, leading to the emergence of distinctive features such as highly-concentrated bands of particulates or regions completely void of particulates. This investigation then extends to flows over an axisymmetric double-cone geometry, focusing on the dynamics of particulates within vortex-dominated systems where particulate-inertia-driven interactions with vortices result in unique particulate-free zones in the vicinity of the primary and secondary vortices. Additionally, this work addresses the importance of using realistic fractal-like particulate shapes and demonstrates that the shape effect tends to decelerate the fractal aggregates and trap them along the boundaries of the primary vortex. This research contributes to a fundamental understanding of gas-solid multiphase flow system dynamics in extreme flight conditions, offering insights relevant to aerospace and aerodynamic applications.

Graduation Semester

2024-08

Type of Resource

Thesis

Handle URL

https://hdl.handle.net/2142/125598

Copyright and License Information

Copyright 2024 Nathaniel K. Myers

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