Citation
Davis, Branson William (2026) Autoignition Modeling and a Generalized Hot Surface Ignition Criterion. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/meyv-1317. https://resolver.caltech.edu/CaltechTHESIS:08262025-221106238
Abstract
This work investigates the fundamental physics and predictive modeling of thermal ignition in heated volumes and near hot surfaces. Three-dimensional simulations of the ASTM-E659 apparatus revealed how natural convection and fuel stratification influence ignition timing and location, highlighting key limitations in standardized AIT testing. A one-dimensional analog further demonstrated the impact of radial temperature gradients on ignition behavior.
To isolate the core mechanisms of thermal runaway, a canonical hot surface ignition problem was analyzed, showing that inclusion of low-temperature chemistry induces two-stage ignition and lowers critical surface temperatures. Building on insights from classical theory, a novel ignition model was developed based on chemical and thermal length scales. The model collapses ignition data across a wide range of configurations and defines a critical Damköhler number. Despite some limitations for NTC fuels and catalytic effects, this unified framework represents a major advance over existing models.
| Item Type: | Thesis (Dissertation (Ph.D.)) | |||||||||
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| Subject Keywords: | Thermal ignition; Autoignition; Hot Surface Ignition; Combustion Modeling | |||||||||
| Degree Grantor: | California Institute of Technology | |||||||||
| Division: | Engineering and Applied Science | |||||||||
| Major Option: | Aeronautics | |||||||||
| Thesis Availability: | Restricted to Caltech community only | |||||||||
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| Group: | Explosion Dynamics Laboratory, GALCIT | |||||||||
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| Defense Date: | 14 August 2025 | |||||||||
| Non-Caltech Author Email: | branson.davis10 (AT) gmail.com | |||||||||
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| Record Number: | CaltechTHESIS:08262025-221106238 | |||||||||
| Persistent URL: | https://resolver.caltech.edu/CaltechTHESIS:08262025-221106238 | |||||||||
| DOI: | 10.7907/meyv-1317 | |||||||||
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| Default Usage Policy: | No commercial reproduction, distribution, display or performance rights in this work are provided. | |||||||||
| ID Code: | 17653 | |||||||||
| Collection: | CaltechTHESIS | |||||||||
| Deposited By: | Branson Davis | |||||||||
| Deposited On: | 28 Aug 2025 07:40 | |||||||||
| Last Modified: | 28 Aug 2025 07:40 |
Thesis Files
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