Two Dimensional Axisymmetric CFD Model of a Natural Draft Wood Fueled Rocket Cookstove

摘要

This paper presents a two dimensional axisymmetric CFD model of a generic cookstove belonging to the 'rocket stove' category with explicit combustion, turbulence and realistic boundary conditions. The model includes combustion modeled by an 11 species, 21-step chemical kinetic mechanism, radiation from the soot-laden gas and the walls, as well as heat loss from the sides of the cookstove and heat delivered to the cookpot. We show the predicted temperature distributions, species distributions and flow field inside the cookstove, along with predictions of the airflow rate through the cookstove and heat transfer to the cookpot. The model is validated against experimental data collected as part of the study. We analyze the effects of the pot support height, secondary air injection, and baffle placement within the cookstove on combustion, flow and heat transfer. We predict the excess air for many configurations of the cookstove and find that it is typically many times stoichiometric during standard operating conditions, and is also sensitive to obstructions. Furthermore, secondary air injection by itself is ineffectual in increasing mixing, but is more effective when coupled with a central baffle. We also find that a lower pot support height results in higher heat transfer efficiency.