A DPIV MEASUREMENT AND CFD SIMULATION OF VISCOUS FLUID FLOW IN A STIRRED TANK AGITATED BY A RUSHTON TURBINE

Mixing, achieved mostly by mechanically stirring, is one of the most important unit operation processes in chemical and allied industries. The problem of designing and scaling-up stirred tanks has been tackled mainly by means of semi-empirical methods. Measurement and numerical simulation of viscous fluid in a stirred tank is still unsufficient and further development is needed. In this paper, computational fluid dynamics (CFD) simulation and digital particle image velocimetry (DPIV) measurement have been carried out to study the flow filed of viscous fluid in a stirred tank agitated by a four-blade Ruston turbine. The working medium is the mixtures of water and glycerine with various concentrations. The results show mean velocity, turbulent energy and vorticity of the fluids as well as the flow patterns change with the fluid viscosity. CFD code of CFX with sliding grids was used to simulate the flow field. The k-ε model was selected as the turbulent models of simulation. The CFD simulations were compared with the experimental DPIV data. The result shows that the CFD simulations reflect the flow of the viscous fluid in a stirred tank. Keywords stirred tank, DPIV, CFD, viscous fluid, turbulence model