关键词: 三维射流角度, 分离强度, 射流, 旋流, 冲击深度

Abstract: In order to explore the relationship between the relative flow direction and the mixing performance of the jet and the cross-flow of the central multi-strand jet reactor, the concept of three-dimensional jet angle represented by normal angle α and rotation angle θ was proposed and defined, and the mixing performance of various jet angles in space was simulated by fluent multiphase flow model. Firstly, the conditions of the numerical simulation were determined by the combination of numerical simulation and experiment, so as to ensure the accuracy of the simulation and conform to the regularity of the experiment. The results showed that under the mixture model, the concentration field obtained by the simulation was close to the distribution law obtained by the experiment, so the simulation can better reflect the internal concentration distribution of the reactor. Secondly, the reactor under the research angle was analyzed through the simulation, the qualitative analysis was carried out through the concentration contour of each section, and the quantitative analysis of the separation intensity of the cross-section, and the change law of the angle on the swirl intensity in the reactor were studied. It was found that θ=67.5° is the ideal rotation angle, and the reactors showed a good mixing effect at this angle. With the increase of θ, the pitch of the fluid trajectory at the mixing development section decreased gradually, and the swirling intensity increased gradually. The pressure drop of the inlet and outlet sections increased with the increase of the rotation angle, and the increase amplitude increased with the increase of the normal angle. At α=30°, θ=90° the slope of the separation intensity decreased the most, indicating that it can make the separation strength reach 0.05. With the increase of θ, the pitch of the mixed development section decreased and the swirling effect increased. The distance of the jet hitting the wall was proportional to the α and inversely proportional to θ.

Key words: three-dimensional jet angle, separation strength, jet flow, swirling flow, impact depth