نوع مقاله : مقاله پژوهشی
1 حرارت و سیالات، مکانیک، تربیت دبیر شهید رجایی،تهران، ایران
2 حرارت و سیالات، مکانیک، تربیت دبیر شهید رجایی، تهران، ایران
عنوان مقاله [English]
Homogenization of lean air-fuel mixture decrease flame front temperature and simultaneously reduces NOx and particulate matter. Experimental work has been shown high level of dispersion can be obtained by impingement of diesel jet onto a matrix of cylindrical obstacles in accordance structure close to Porous media. The injected fuel impinges with the first cylindrical obstacle and splits to two smaller jets and with impingement with other obstacles causes to multi-jets formation causes to fuel dispersion. Previous experimental works have been shown geometrical structure and obstacle diameter are of key factors in multi‐jet formation and spatial distribution of the charge. In this paper, computational fluid dynamics models that accurately predict the formation behavior of several transient multi-jet are developed, and after validation, new structures of obstacles with increasing distances between them and an improved structure are proposed as novel innovations. New modeling shows that these structures have better homogenization properties and space distribution is more efficient than the structures previously studied. Also, with increasing the distance between the cylindrical obstacles, the diffusion and penetration of some fuel jets has increased and for all geometrical structures, it has increased the fuel distribution angle. The geometrical structure of the obstacles is very important to achieve the proper fuel distribution pattern and is not dependent on the number of obstacles.