Modification of flow characteristics by wall roughness has been intensively analyzed in the field of fluid mechanics. However, few studies have considered wall roughness in boundary layer flame flashback. In the present study, laminar boundary layer flashback in channels with roughness at the walls is studied using two-dimensional simulations. The laminar premixed flame interacts with a linear shear flow along a wall with triangle-shaped fine roughness. The simulation results show that wall roughness in this configuration can attenuate flashback tendency due to enhanced heat loss to the boundary. By comparing results for isothermal and adiabatic boundary conditions at the walls, it is shown that the heat loss enhancement due to wall roughness may be a dominant effect in determining flame propagation characteristics for the walls with low thermal resistance. The critical velocity gradient is shown to decrease with wall roughness level and increase with thermal gas expansion ratio.

中文翻译：

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壁面粗糙度对层流边界层回火影响的数值研究

在流体力学领域，已经对通过壁粗糙度对流动特性的改变进行了深入分析。但是，很少有研究考虑边界层火焰回火中的壁粗糙度。在本研究中，使用二维模拟研究了壁面粗糙的通道中的层流边界层回火。层流预混火焰与具有三角形精细粗糙度的壁上的线性剪切流相互作用。仿真结果表明，由于增加了向边界的热损失，这种配置下的壁面粗糙度可以减弱回火趋势。通过比较壁的等温和绝热边界条件的结果，结果表明，由于壁粗糙度造成的热损失增加可能是确定具有低热阻的壁的火焰传播特性的主要作用。临界速度梯度显示出随着壁粗糙度的增加而减小，并且随着热气体膨胀率而增加。