Experimental Investigation of Flow and Thermal Patterns in the Rotated Arc Mixer

Thermal patterns emerging during the downstream evolution of temperature fields in industrial inline mixers have been studied numerically yet experimental observation remains outstanding. This research concerns a comparative analysis between experimental and numerical studies on the evolution of the temperature fields of a representative configuration, namely the Rotated Arc Mixer (RAM), and its correlation with the flow field. The RAM is an inline mixer that is composed of a stationary inner cylinder with consecutive apertures and a rotating outer cylinder inducing transverse flow at the apertures. Design of the experimental facility is based on a 2D time-periodic simplification of the 3D spatially-periodic RAM, where the cross-sectional progression is represented by the temporal evolution. The setup consists of a circular test section with apertures on the circumference and motor-driven belts imitating the rotating cylinder. Constant circumferential temperature is achieved by an enclosing annular hot-water reservoir. The 2D flow and temperature fields are measured by 2D Particle-Imaging Velocimetry and Infrared Thermography. Preliminary results have exposed a clear correlation between temperature and flow fields: thermal patterns evolve in accordance with the time-periodic flow patterns and become persistent ultimately.