This article briefly reviews the recent works related to small-scale combustion and its potential impact into combustion science and engineering is presented. Followed by a simple description of the scale effect on combustion to highlight its “unique” feature, past related works are then summarized. The impact of heat recirculation appearing in combustion systems, which is the most prominent feature of a micro- or small-scale combustion system, is focused upon and is understood that exactly the same strategy promising better combustion performance is confirmed irrespective of flame type (either premixed or non-premixed). With respect to this, paying attention to the entire combustor design, to optimize within the target working range is a crucial matter when micro-scale combustion is adopted. Potential subjects to be covered to further promote these aspects in this field are then presented.
A finite volume based three dimensional numerical studies on the heat transfer due to natural convection inside the inclined cubical cavity filled with CNT-water nanofluid is solved by vorticity-vector potential formalism. The enclosure contains an Ahmed body at its middle with differentially heated vertical walls. The other walls are adiabatic. The effect due to Rayleigh number (103 ≤ Ra ≤ 105), volumetric fraction (0 ≤ φ ≤ 0.05) of CNT particles, angle of incidence of enclosure (0° ≤ γ ≤ 180°) and thermal conductivity ratio (0.01 ≤ Rc ≤ 100) are analyzed. The results of fluid flow with single phase model are elucidated with Particle trajectories, Velocity vectors, Iso-surfaces of temperature and Nusselt number. CNT-particles enhanced the heat transfer in all the considered cases. Maximum average Nusselt number is reported when the angle of inclination is 30° and 150°. The variation in thermal conductivity ratio has a least effect on convection.
Edited and published by : The Japan Society of Mechanical Engineers and The Heat Transfer Society of Japan Produced and listed by : Showa Joho Process Co., Ltd.(Vol.8 No.3-) Sanbi Printing Co., Ltd.(Vol.1 No.1-Vol.8 No.2)