| Low Swirl Combustion (LSC) is a new technique to steady the flame which is different from other traditional Swirl Combustion. In the center flow field, the axial velocity has the higher attenuation, the flame front exists at the position where the local velocity is reverse and equal to the flame propagation velocity and there is a dynamic balance between them. In terms of IGCC system, Low Swirl Injector(LSI) can be used as a plug-in component, which has the simpler structure and lower cost. What’s more, it has the potential for adaptation to fuel-flexible gas turbines operating on a variety of fuels. The objective of this study is to gain a fundamental understanding of the effect of swirl number on the LSC cold state flow field.In this paper, the swirler is designed. Through the variation of the blockage ratio to the center perforated plate, the swirl number changes. Then the cold state flow fields of six groups are captured by using a Particle Image Velocimetry (PIV) system. At the same time, the simulation is also done. The conclusions are shown as follows:(1)The demarcation swirl number between high and low is 0.55, and the low swirl flow field formed "W" shape distribution which shows self-similarity features. (2) The attenuation of the velocity is high in the center channel, which is associated with swirl number. But the velocity in the annular channel seems weekly influenced by the swirl number. (3) The turbulent kinetic energy is small in the center flow field, which is available to provide the sufficient combustion. The center turbulent kinetic energy reduces with the increase of swirl number, and the annular turbulent kinetic energy is on the contrary. (4) The distribution and change rate of the radial velocity are associated with swirl number, and the increasing of the swirl number intensifies the diffusion. (5) The peak of the tangential velocity increases with the rise of swirl number, but the distribution is weekly influenced by it. |
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