Theory of supercritical flames with real-fluid equations of state

Abstract

We report a theoretical analysis of the propagation and structure of the planar adiabatic/radiative flame in supercritical fluids, employing the Van der Waals and the Redlich-Kwong equations of state to describe the fluid properties. It is demonstrated that the effective molecular volume and attractive force terms in these non-ideal equations of state show opposite effects on the density modification, especially in the upstream unburned region. Furthermore, the non-ideal effect is found to strongly couple with radiative emission and reabsorption, whose respective weakening and strengthening effect can substantially affect the state of radiation-induced quenching. The theory is useful for the description of high-pressure flames as both the non-ideal state and radiation become more pronounced under such conditions.

Keywords:

• supercritical fluids
• equation of state
• flame theory

Acknowledgement

This research was sponsored by the US AFOSR under the technical monitoring of Dr. Mitat Birkan.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by US AFOSR.