Temperature coupling effects in radiatively heated particle-laden flows
Abstract/Contents
- Abstract
- Turbulent particle-laden flows are common in many natural phenomena and engineering applications. While particle-laden turbulence is a relatively well-studied subject, not many studies address the concurrent effect of an radiative heat transfer on the multiphase system. Understanding such an interaction can be key to designing effective spray combustors, fire suppression systems, and particle solar receivers. Using the particle solar receiver as a test bed for investigation, this work aims to experimentally investigate the coupling between radiation, turbulence, and particles in such a system using two different flow configurations of a duct flow and an isokinetic co-flowing jet. The goals of the work are to examine the effects of preferential concentration on the behavior of the radiation transport through the disperse medium and the convective heat transfer between the carrier and disperse phase. In addition, it also aims to study the converse effect of how the radiative heating can effect the clustering behavior of the particles by examining measures of preferential concentration of particles in the flow in the presence of radiative heating. The study finds that the preferential concentration of particles can cause the radiation transmission to deviate from a classical Beer's Law extinction behavior, due to increased line of sight distances in the medium. Measurements of the carrier phase temperature statistics show that large coherent particles clusters dominate the modulation of the gas phase temperature, especially in the boundary layer in wall-bounded flows. Measurements of the radial distribution function, clustering index, and Voronoi cell area PDFs all indicated a reduction of preferential concentration within clusters, particularly in denser clusters with smaller associated separation length scales, which correspond to the most intensely heated regions of the flow. Particle velocity statistics showed evidence of bulk turbulence modification by radiative heating, as particle velocity fluctuations were dampened. This was likely caused by variable property effects from temperature-dependent properties, specifically from the increase in fluid kinematic viscosity. Buoyancy and dilatation effects were identified as possible mechanisms for turbulence modification at the smaller cluster scales, supported by scaling analyses and directional measures of preferential concentration.
Description
| Type of resource | text |
|---|---|
| Form | electronic resource; remote; computer; online resource |
| Extent | 1 online resource. |
| Place | California |
| Place | [Stanford, California] |
| Publisher | [Stanford University] |
| Copyright date | 2022; ©2022 |
| Publication date | 2022; 2022 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Author | Kim, Ji Hoon |
|---|---|
| Degree supervisor | Eaton, John K |
| Thesis advisor | Eaton, John K |
| Thesis advisor | Iaccarino, Gianluca |
| Thesis advisor | Mani, Ali, (Professor of mechanical engineering) |
| Degree committee member | Iaccarino, Gianluca |
| Degree committee member | Mani, Ali, (Professor of mechanical engineering) |
| Associated with | Stanford University, Department of Mechanical Engineering |
Subjects
| Genre | Theses |
|---|---|
| Genre | Text |
Bibliographic information
| Statement of responsibility | Ji Hoon Kim. |
|---|---|
| Note | Submitted to the Department of Mechanical Engineering. |
| Thesis | Thesis Ph.D. Stanford University 2022. |
| Location | https://purl.stanford.edu/mb273ph7692 |
Access conditions
- Copyright
- © 2022 by Ji Hoon Kim
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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