Research On Generation And Movement Of Smoke Ring In Exhaust Emission

The motion of smoke ring is interesting, and it always attracted physicists, mathematicians and engineers because of its extensive theoretical and practical value.The purpose of this paper is to explore a new method of lifting smoke to reduce the concentration of pollutant near the chimney by researching the generation and movement of smoke ring.The main contents of this paper contain: Firstly, summarized some measures and technologies on waste gas treatment and exhaust emission, epitomized the research history and current status of vortex rings. And then, did flow field simulation with FLOTRAN for the generation and movement of smoke rings under certain devices and conditions; analyzed the changing of smoke ring as soon as it had occurred; compared and analyzed the influence factors on smoke rings and compared the difference of situations whether it produced smoke rings. Finally, designed the smoke ring device and then do practical field experiments, verified some results of the simulation analysis.After the simulation and field experiment, this paper got the following conclusions: First, compared with the situation of no smoke ring produced, smoke ring movement can upraise the smoke to higher position actually. This is advantageous for the diffusion of exhaust gas. Second, for the device which generates smoke rings in this paper, when the disk moved to the top of cylinder, high pressure would generate at the orifice; and when it stopped, low pressure produced. And then, gas on the side of the orifice flowed to the center because of the different pressures. So, smoke ring began to generate. Third, for the device which generates smoke rings in this paper, in the early of smoke ring produced, its radius is to become smaller with the change of time, and then remained relatively stable and gradually become larger; the rate of rise has also gradually slowed down. Fourth, for the device which generates smoke rings in this paper, the orifice diameter of cylinder, the size ratio of orifice and circular push board, speed and distance of travel of circular push board are all influence factors to smoke rings. Only when all factors are in certain ranges, it's possible to produce smoke ring. Smoke ring can generate easier when orifice is bigger, when the speed of circular push board is moderate and when the travel distance of circular push board is large enough. Fifth,among all factors that affect height that the smoke ring can reach , they are the orifice diameter of cylinder, the distance of travel of circular push board and the speed of travel of circular push board in order of their affecting lever.