RESUMO

Analysis and identification of vortex structures and their formation, particularly in swirl flows, have received widespread interest among researchers in the field of fluid mechanics. Due to the importance of vortex structures and their applications in combustion chambers, a special type of combustion chamber, which is called a "bidirectional swirl combustor", has been investigated in this work. The dependence of vortex structures on the combustion chamber geometry and fuel injection location in cold flow, the effect of hot flow on coherent structures, and the difference between vortex structures in hot and cold flows have been studied as well. A common characteristic which is in combustion chambers and cyclones alike and that has not yet been exactly surveyed is swirl intensity and its variation along the length of the combustion chamber In this study, the velocity profiles obtained from the numerical simulation have been used to determine swirl intensity profiles along the combustion chamber axis for various models. Numerical solutions have been performed via OpenFOAM software. The results show that the mean vortex intensity increases while the combustion chamber length decreases. Also, comparison of the reactive flow with the nonreactive flow shows that the vortex intensity in the hot chamber is approximately half of its value for the cold flow. Unlike the cold chamber model, there is no opportunity to form small recirculation zones in the hot model due to the heat release and increment of the axial momentum.