Measurements of Non-reacting and Reacting Flow Fields of a Liquid Swirl Flame Burner

The understanding of the liquid fuel spray and flow field characteristics inside a combustor is crucial for designing a fuel efficient and low emission device.Characterisation of the flow field of a model gas turbine liquid swirl burner is performed by using a2-D particle imaging velocimetry（PIV）system.The flow field pattern of an axial flow burner with a fixed swirl intensity is compared under confined and unconfined conditions,i.e.,with and without the combustor wall.The effect of temperature on the main swirling air flow is investigated under open and non-reacting conditions.The result shows that axial and radial velocities increase as a result of decreased flow density and increased flow volume.The flow field of the main swirling flow with liquid fuel spray injection is compared to non-spray swirling flow.Introduction of liquid fuel spray changes the swirl air flow field at the burner outlet,where the radial velocity components increase for both open and confined environment.Under reacting condition,the enclosure generates a corner recirculation zone that intensifies the strength of radial velocity.The reverse flow and corner recirculation zone assists in stabilizing the flame by preheating the reactants.The flow field data can be used as validation target for swirl combustion modelling.

WEAKLY SWIRLING TURBULENT FLOW IN TURBID WATER HYDRAULIC SEPARATION DEVICE

This article deals with the characteristics of weakly swirling turbulent flow field in a Turbid Water Hydraulic Separation Device （TWHSD） through experimental and numerical researches. The flow field was measured by PIV, which provided streamlines, vortex structure, vorticity and velocity distribution in different test planes in the TWHSD. On the basis of the experimental results, the tangential and radial velocity distributions of the swirling flow field were obtained. Meanwhile, the numerical simulations were conducted with the RNG κ-ε and RSM turbulence models, respectively. According to the experimental and numerical results, the characteristics of the clear water flow field inside the TWHSD were determined. In view of simulation accuracy and time consumption, it is suggested to apply the RNG κ-ε model instead of the RSM model, which is more time consuming, to make further study on two-phases flow fields in the device.

Experimental study of droplet behavior in a swirl flow field induced by two kinds of guiding vanes and inlet structure optimization

Droplet breakage is a common phenomenon in converting a pipe flow to a swirl flow in a vane-type pipe separator(VTPS)’inlet.The evaluation of the dispersed droplet sizes after breakage is crucial to the optimum design of the inlet structure and the estimation of the oil-water separation performance.This paper studies the droplet behavior in a swirl flow produced by guiding vanes.Experiments are performed with two different guiding vanes at the inlet of the VTPS.The sizes of the produced oil droplets at the downstream of the guiding vanes are measured in situ using a Malvern Insitec SX.The results indicate that the streamlined deflector is superior to the semi-elliptical plate for the VTPS’optimization based on the comparison of the droplet sizes in their respective induced swirl flow fields,which can be explained by a modified T-model.Our study suggests that the use of the modified T-model is a reliable method to optimize the design of the guiding vane in the swirling generating stage.