In this work, we examine the bluff body effect on thermal and NO_x emission performance in a micro-planar combustor fueled with premixed ammonia/oxygen using three-dimensional numerical simulations. For this, a three-dimensional model is developed with a detailed chemical kinetic mechanism. The effects of 1) the presence/absence of the bluff-body, 2) its dimensionless height h and 3) its dimensionless axial location l are examined. It is found that the implementation of a bluff-body can significantly affects the thermal and NO emission characteristics. Up to 39.1 % reduction of NO formation and 41.6 K increase in the outer wall temperature (OWT) can be achieved as the bluff-body is optimized, when compared to the case in the absence of the bluff-body. Furthermore, increasing h leads to OWT being increased, but it can suppress the NO generation in some cases. In addition, increasing l is shown to be involved with a high OWT and a low NO concentration, mainly due to the variation in the flow field and thus heat transfer characteristics. Finally, the dimensionless pressure loss is strongly affected by the NH₃ flow rate, and the dimensionless parameters h and l. This work reveals that implementing a proper designed bluff-body is an effective way to enhance thermal performance and reduce NO_x emission.

在这项工作中，我们研究的热的含非流线形体的效果和NO _X与使用三维数字模拟预混氨/氧燃料的微平面燃烧室排放性能。为此，建立了具有详细化学动力学机理的三维模型。1）钝体的存在/不存在； 2）无量纲高度h； 3）无量纲轴向位置l的影响被检查。发现钝体的实施可显着影响热和NO排放特性。与不存在钝体的情况相比，通过优化钝体，可以减少多达39.1％的NO生成并增加41.6 K的外壁温度（OWT）。此外，增加h导致OWT增加，但是在某些情况下可以抑制NO的产生。另外，显示出增加的l与高OWT和低NO浓度有关，这主要是由于流场的变化以及因此的传热特性的变化。最后，无量纲压力损失受NH ₃流量的强烈影响，无量纲参数h和l。这项工作表明，实施适当的设计钝体是提高散热性能和降低NO的有效途径_X的排放。