# Modeling subgrid combustion processes in simulations of thermonuclear supernovae

## TL;DR

This paper reviews the challenges in simulating subgrid combustion processes in thermonuclear supernovae, focusing on deflagration and detonation models, and discusses approaches for modeling these small-scale phenomena within large-scale supernova simulations.

## Contribution

It provides an overview of the computational challenges and modeling strategies for subgrid combustion processes in supernova explosion simulations.

## Key findings

- Discussion of deflagration and detonation propagation modes.
- Identification of scale disparities in supernova modeling.
- Overview of subgrid model verification methods.

## Abstract

Supernovae of type Ia are thought to arise from the thermonuclear incineration of a carbon-oxygen white dwarf stellar remnant. However, the detailed explosion scenario and stellar evolutionary origin scenario -- or scenarios -- which lead to observed supernovae are still quite uncertain. One of the principal tests of proposed scenarios is comparison with the explosion products inferred, for example, from the spectrum of the supernovae. Making this comparison requires computation of the combustion dynamics and products through simulation of proposed scenarios. Here we discuss two specific proposed explosion scenarios, the deflagration-detonation transition and the helium shell double detonation, With these two examples in mind, we proceed to discuss challenges to computational modeling of the combustion taking place in these explosions. Both subsonically and supersonically propagating reaction fronts are discussed, called deflagrations and detonations respectively. Several major stages of the combustion occur on length and time scales that are many orders of magnitude smaller than those accessible in simulations of the explosion. Models which attempt to capture this sub-grid behavior and the verification of those models is briefly discussed.