WS1 固有不安定性による予混合火炎の非定常挙動

概要

論文の詳細を見る
Two-dimensional (2-D) and three-dimensional (3-D) reactive flows are calculated to study the unsteady behavior of premixed flames due to intrinsic instability. The compressible Navier-Stokes equation including a one-step irreversible chemical reaction is employed. We consider three basic effects responsible for the intrinsic instability of premixed flames, i.e., the hydrodynamic, diffusive-thermal, and body-force effects. These effects have a great influence on the instability of flame fronts. As the flame temperature increases, the instability level becomes higher. When the Lewis number is higher (lower) than unity, the growth rate decreases (increases) and the unstable range narrows (widens). When flames are propagated downward (upward), the flame front becomes stable (unstable). A disturbance superimposed on a planar flame is evolved by intrinsic instability, and then a cellular flame is formed. At the Lewis number of unity, the cellular flame is stationary. At Lewis numbers lower than unity, on the other hand, the cellular flame moves laterally, and the lateral velocity of 2-D flames is about twice that of 3-D flames, which is due to diffusive-thermal instability.
日本流体力学会の論文
2001-07-31