A conservative, thermodynamically consistent numerical approach for low Mach number combustion. Part I: Single-level integration

Abstract

We present a numerical approach for low Mach number combustion that conserves both mass and energy while remaining on the equation of state to a desired tolerance. We present both unconfined and confined cases, where in the latter the ambient pressure changes over time. Our overall scheme is a projection method for the velocity coupled to a multi-implicit spectral deferred corrections (SDC) approach to integrate the mass and energy equations. The iterative nature of SDC methods allows us to incorporate a series of pressure discrepancy corrections naturally that lead to additional mass and energy influx/outflux in each finite volume cell in order to satisfy the equation of state. The method is second order, and satisfies the equation of state to a desired tolerance with increasing iterations. Motivated by experimental results, we test our algorithm on hydrogen flames with detailed kinetics. We examine the morphology of thermodiffusively unstable cylindrical premixed flames in high-pressure environments for confined and unconfined cases. We also demonstrate that our algorithm maintains the equation of state for premixed methane flames and non-premixed dimethyl ether jet flames.

Keywords:

• low Mach number combustion
• detailed chemistry and kinetics
• thermodynamic pressure
• confined domains
• spectral deferred corrections

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

Work at the Lawrence Berkeley National Laboratory was supported by the Applied Mathematics Program of the Department of Energy (DOE) Office of Advanced Scientific Computing Research under US DOE contract [DE-AC02-05CH11231].