An LDA Study of Shear rate profiles of Rushton turbine in mixing tanks

In this article, distributions of local shear rates for Rushton turbine impeller have been studied using laser Doppler Anemometry (LDA) for viscoelastic liquids. The normalized local tangential velocity and local shear rate profiles are independent of Rushton turbine impeller speeds and main variations of shear rate occur in the vicinity of impeller. This is due to the large variations in tangential velocity in this region. In the transition region, i. e. ∼30 < Re < ∼2000, tangential velocity component and local shear rate, are shown to be negligible at axial coordinate of z = 0.0315 m above impeller tip plane, i. e. z = 0.

Keywords:

Anemometry (LDA) , Local shear rate , Viscoelastic liquids , Mixing , Rushton turbine impeller