This research investigates the transient flame propagation and oscillation phenomenon in the flame speed of porous biochar dust cloud. Time-dependent mass, momentum and energy equations are solved in the spherical coordinate. The gas phase reaction includes the chemical reactions, thermodynamic properties, and multi-element transition properties. To account for the porosity effects of particles, the biochar dusts are modeled as spherical particles with unlimited number of pores (semi sphere) on the surface. The particle trajectory is governed by the equation of motion. The thermophoretic, gravitational, buoyancy and drag forces are employed in this model. In the energy equation, the absorption and radiation emissions by particles is considered. The results reveal that the inertia differences between the particles and gas causes a difference in the velocities of these two phases at the flame front—which is more evident at the early stages of flame propagation when there is a significant change in the density of dust particles. Moreover, the oscillation is further intensified by enhancing the oxygen concentration due to a higher reaction rate, and, as a result, higher velocity difference between the two phases.

本研究调查了多孔生物炭粉尘云火焰速度中的瞬态火焰传播和振荡现象。在球坐标系中求解与时间相关的质量、动量和能量方程。气相反应包括化学反应、热力学性质和多元素转变性质。考虑到颗粒的孔隙率效应，生物炭粉尘被建模为球形颗粒，表面具有无限数量的孔隙（半球形）。粒子轨迹由运动方程控制。该模型采用热泳力、重力、浮力和阻力。在能量方程中，考虑了粒子的吸收和辐射发射。结果表明，粒子和气体之间的惯性差异​​导致这两个相在火焰前沿的速度存在差异——这在火焰传播的早期阶段更为明显，当灰尘粒子的密度发生显着变化时. 此外，由于较高的反应速率和结果，两相之间的速度差较大，因此通过提高氧气浓度来进一步加强振荡。