Investigating the effects of different blockages with the same blocking ratio in a low-swirl combustion

In this article, an investigation is conducted into the impacts arising from variations in the configuration of apertures within a perforated plate employed in the context of low-swirl premixed combustion. To this end, a four-blade burner characterized by a radius of 7 mm is employed, along with a perforated plate possessing a radius of 4.5 mm. The blockage ratio, held at a constant value of 0.88, encompasses a set of 9 orifices, each explored across 5 distinct configurations. Computational analysis is executed utilizing the Ansys Fluent software, encompassing the resolution of the three-dimensional Navier-Stokes equations coupled with the k-ω standard turbulence model. Within this study, the role of oxidizer and fuel is played by air and methane respectively, under an equivalence ratio of 0.65. The outcomes of this investigation reveal a notable constancy in the general flow behavior despite the altered orifice arrangements. At the same time, the maximum total temperature and the average flow rotation change by 1% and 3%, respectively. In addition, in the flame formation area, the location and angles of the flame are changed by 17%, 7% and 19%, Furthermore, a downward shift of the flame by 8.8 mm is discerned consequent to modifications in the spacing between apertures within the perforated plate. Additionally, from an emissions mitigation perspective in combustion processes, it is noteworthy that there exists a discernible disparity of approximately 12% between the maximal and minimal levels of nitrogen oxide emissions generated.