Abstract
The chemical vapor infiltration (CVI) process involves infiltrating a porous preform with reacting gases that undergo chemical transformation at high temperatures to deposit the ceramic phase within the pores, ultimately leading to a dense composite. The conventional CVI process in composite manufacturing needs to follow an isothermal approach to minimize temperature differences between the external and internal surfaces of the preform, ensuring that reactive gases infiltrate internal pores before external surfaces seal. This study addresses the challenge of premature pore closure in CVI processes through microwave heating. A frequency-domain microwave solver is developed in OpenFOAM to investigate volumetric heating mechanisms within the preform. Through numerical studies, we demonstrate the capability of microwave heating of creating an inside-out temperature inversion. This inversion accelerates reactions proximal to the preform center, effectively mitigating the risk of premature external pore closure and ensuring uniform densification. The results reveal a significant enhancement in temperature inversion when high-permittivity reflectors are incorporated to generate resonant waves. This microwave heating strategy is then coupled with high-fidelity direct numerical simulation (DNS) of reacting flow, enabling the analysis of resulting densification processes. The DNS includes detailed chemistry and realistic diffusion coefficients. The numerical results can be used to estimate the impact of microwave-induced temperature inversion on densification in productions.
| Original language | English |
|---|---|
| Article number | 042201 |
| Journal | ASME Journal of Heat and Mass Transfer |
| Volume | 147 |
| Issue number | 4 |
| DOIs | |
| State | Published - Apr 1 2025 |
Funding
This research was supported by the High-Performance Computing for Manufacturing Program (HPC4Mfg), managed by the U.S. Department of Energy (DOE), Advanced Manufacturing Office (AMO) within the Energy Efficiency and Renewable Energy (EERE) Office. This research used resources of the Oak Ridge Leadership Computing Facility (OLCF) and Compute and Data Environment for Science (CADES) at the ORNL, which is supported by the Office of Science of the U.S. DOE under Contract No. DE-AC05-00OR22725. The authors acknowledge the contributions of Jake Parsons and Christopher Ibarra whose internships were supported by HPC4Mfg Internship Program. This manuscript has been authored by UT-Battelle, LLC, under contract DE-AC05-00OR22725 with the U.S. Department of Energy (DOE). The U.S. government retains and the publisher, by accepting the article for publication, acknowledges that the U.S. government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for U.S. government purposes. DOE will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (http://energy.gov/downloads/doe-public-access-plan). Office of Energy Efficiency and Renewable Energy (Award No.: HPC4Mfg; Funder ID: 10.13039/100006134).