Modelling of candle burning with a self-trimmed wick

Abstract

As an example of a coupled gas-phase diffusion flame with porous media flow, a candle burning model with a porous wick is offered in this paper. The porous media analysis includes capillarity-induced liquid flow, liquid vaporisation, vapour motion and re-condensation and multi-phase heat transfer. Coupling with the gas phase flame is through the conservation of mass, momentum and energy at the wick surface. The steady state solutions obtained not only yield the flame structure but also the detailed flow pattern and saturation distributions inside the wick. One of the novel features of the present model is the capability to address the self-trimming phenomena of candle burning. The self-trimming wick length and the associated flame characteristics have been computed as a function of gravity level, wick permeability and wick diameter.

Keywords:

• candle flame
• porous wick
• self-trimming
• flame-porous-media-flow coupling

Acknowledgments

This work has been supported by NASA grant NNC04GB34G with Dr Daniel Dietrich as the grant monitor.