Burning Speed and Entropy Production Calculation of a Transient Expanding Spherical Laminar Flame Using a Thermodynamic Model

Abstract

A thermodynamic model has been developed to calculate burning speed and entropy production of transient expending spherical laminar flame in an enclosed vessel. The model also predicts the particle trajectories of both unburned and burned gases in the vessel. The input to this model is the dynamic pressure rise due to combustion process. The unburned gases are divided into three regions: The core unburned gases which are compressed isentropically, the vessel walls and electrodes boundary layer gases, and gases in the preheat zone of the flames. The burned gases are in many shells having the same pressure but different temperatures. The model also includes radiation losses from the burned gases to vessel walls. Entropy production due to irreversibility has been calculated by applying entropy balance to the gas mixtures. Burning speed of premixed n-decane air mixture has been reported for temperatures and pressures along an isentrope.