Simulation Study: The Role of Area to Volume Ratio and Key Parameters in Cylindrical Micro Combustors

A micro combustor is one of important devices in heat generation to power miniaturized products such as microrobots, notebook computers, micro-aerial vehicles and other small scale devices. An integrated micro combustor with thermophotovoltaic (TPV) in a micro-size electric generator supplies electricity to these micro devices. There is a growing interest in developing micro combustors as a power source due to their inherent advantages of higher energy density, higher heat and mass transfer coefficients and shorter recharge times compared to electrochemical batteries. A new micro combustion concept is described in this work by introducing a new terminology in the micro combustion. The effects of Area to Volume Ratio (AVR) of the micro-combustors were studied to find the best performance of designed micro-combustors. In order to test the feasibility of the designed micro combustors before the actual experiment is conducted, simulation work was performed. There are three key parameters involved in the current study: Area to Volume Ratio (AVR), Flow Velocity of the mixture (u), and Fuel-Air Equivalent Ratio (Ø). Main results of this experiment are images of temperature contour, graphs of temperature distribution profile, and graphs of mean temperature profile. This study found there is a specific range of mixture flow velocity (0.50 – 0.56 m/s) which result a high and uniform temperature distribution as well as its best mean temperature of micro combustion process. The simulation work could also localized the specific range of AVR-value (1.40 – 2.01) which require further investigation in the future.