Numerical Simulation and Experimental Research of Flow Past Bluff Body in Vertical Upward Gas-Liquid Two-Phase Flow
|Course||Detection Technology and Automation|
|Keywords||flow past bluff body Vortex Shedding Gas-Liquid Two-Phase Flow FLUENT Droplet Numerical Simulation|
Gas-liquid two-phase flow exists widely in nature and industrial production. Comperhending the law of gas-liquid two-phase flow past a bluff body and velocity characteristics can provide a theoretical guarantee for the designation of industrial anti-vibration and the measurement of flow parameters in gas-liquid two-phase flow. However, considering the complexity of gas-liquid two-phase flow field, the real flow state is difficult to be detected. Therefore, using numerical simulation to simulate the real condition can explore the dynamics of flow and establish a closer realationship between numerical simulation and real experiment. Furthermore, this can provide more in-depth reference basis and strong support for the measurement of gas-liquid two-phase flow.Karman Vortex is researched by vortex flowmeter in this paper.In this paper, first to simulate the gas flow past a bluff body by 3D. The error between simulation and experiment is less than 5%, which shows the consistency between simulation and experiment. The signal at the point 1D after the bluff body is more exact and ample than the one at 1.5D according to the simulation.Then the gas-liquid two-phase flow in which the continuous phase is gas and the dispersed is liquid is experimentalized. According to the error, repeatability and theoretics , the result of experiment shows the flow is annular flow if the percentage of water is less than 0.3%, in this condition vortex street is steady. However, if the percentage is above 0.6%, the flow becomes plug converying and the vortex street is unsteady.On the basis of gas simulation, the appropriate simulation conditons are selected for gas-liquid two-phase flow. The error between simulation and experiment is acceptable. The conclusion that there is no vortex street if the percentage of water is above 1% is reached because to the velocity characteristics stress characteristics and droplet characteristics in simulatin. The simulation is also used to analyse how droplets destroy the vortex shedding.