POWER CONSUMPTION OF VISCOELASTIC FLUIDS OUT Of UNAERETED

Most of the elastic fluids are pseudoplastic and this causes difficulties of clear interpretation of the experimental results in which the effects due to inertia, elasticity and the variation of viscosity affect the power consumption, hydrodynamic and the phenomena of heat or mass transfer. In the literature, Nagata is one of the rare authors to propose a correlation of power consumption for Newtonian fluid agitated by two-bladed impeller from laminar to turbulent flow. For the Newtonian fluids agitated by a Rushton turbine, we propose the equation of the number of power consumption Np in relation with the Reynolds number Re: Npn = Kp/Re + (An + NptnRe)/(Cn +Re) with kp = 75; An = 1018; Cn = 431; Nptn = 5,3 kp and Npt are respectively the constants of power consumption in streamline and turbulent flow, An and Cn are coefficients. In viscoelastic area characterized by the number of elasticity Elo (Elo = to/d2) taking into account the properties of the fluid (characteristic time to, viscosity , density ) and the diameter d of the agitator, a correlation of power consumption was proposed. This equation is parameterized by the number of.elasticity Elo and the generalized Reynolds number generalized Reg (Reg = N2-nd2/kkmon-1) according to the concept of Metzner-Otto: Np = Kp/Reg + (A + NptReg)/(C +Reg