Evaluation of the turbulent kinetic dissipation rate in an agitated vessel

• Published in: EPJ Web of Conferences Vol. 143; p. 2062
• Main Authors: Kysela, Bohus, Konfrst, Jiri, Chara, Zdenek, Sulc, Radek, Jasikova, Darina
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Les Ulis EDP Sciences 01.01.2017
• Subjects: Agitation; Baffles; Computational fluid dynamics; Computer simulation; Dissipation; Fluid flow; Kinetic energy; Large eddy simulation; Mathematical models; Navier-Stokes equations; Reynolds averaged Navier-Stokes method; Rushton turbines; Scale models; Vessels
• ISSN: 2100-014X; 2101-6275; 2100-014X
• DOI: 10.1051/epjconf/201714302062

The design of agitated tanks depends on operating conditions and processes for that are used for. An important parameter for the scale-up modelling is the dissipation rate of the turbulent kinetic energy. The dissipation rate is commonly assumed to be a function of the impeller power input. But this approach gives no information about distribution of the dissipation rate inside the agitated volume. In this paper the distributions of the dissipation rate inside the agitated vessels are estimated by evaluations of the CFD (Computational Fluid Dynamics). The results obtained from RANS (Reynolds Averaged Navier-Stokes equations) k-ε turbulent model and LES (Large Eddy Simulations) with Smagorinsky SGS (Sub Grid Scale) model are compared. The agitated vessels with standard geometry equipped with four baffles and stirred by either a standard Rushton turbine or a high shear impeller were investigated. The results are compared with mean dissipation rate estimated from the total impeller power input.