Optimization of radiative property models for fire simulations

• Grant number: 25/24102-4
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2026
• End date: January 31, 2027
• Field of knowledge: Engineering - Mechanical Engineering - Transport Phenomena
• Principal Investigator: Guilherme Crivelli Fraga
• Grantee: Fernando Toshiaki Ueno
• Host Institution: Faculdade de Engenharia Mecânica (FEM). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil

Abstract

Thermal radiation and its spectral characteristics significantly influence temperature fields and combustion dynamics in fire problems. However, accurate line-by-line spectral integration is computationally prohibitive for engineering simulations. This project aims to develop and test reduced-order spectral models based on the Spectrally Reduced Integration (SRI) method to provide a practical compromise between LBL accuracy and computational cost. Two research directions will be pursued: (i) refinement and extension of SRI for multidimensional problems, including new coarsening schemes and alternative spectral importance measures; and (ii) adaptation of SRI tools to identify optimal wide-band intervals and to construct improved wide-band radiative-property models (e.g., stepwise-gray, wide-band cumulative-k, and banded SLW-1 approaches). Implementations will be incorporated into an in-house radiative transfer code and thoroughly verified and validated. Models will be assessed against LBL references and commonly used wide-band formulations on representative two- and three-dimensional fire cases, with evaluation metrics including prediction accuracy and the number of evaluations of the radiative transfer equation (cost). Expected outcomes are more cost-efficient formulations of the SRI method for general benchmark applications, and new, more accurate wide-band models for fire simulations. Deliverables of the project will include a conference presentation and a journal paper. (AU)