Numerical Analysis of Magnetorheological Grease Flow Around Heated Rotating Rollers

Abstract

The present study investigates magnetorheological grease flow in a rectangular channel with two rotating cylinders. Along with a heat transfer analysis, the study focuses on the effect of a magnetic field on the flow of the grease dispersed with two different weight fractions of carbonyl iron particles. With increasing pressure, it has been observed that velocity increases at all locations of the channel. The presence of a magnetic field leads to a reduction in flow velocity. This is explained based on the formation of strong field-induced chain-like networks which increases the resistance to flow. The pressure drop across the channel is dependent on magnetic field strength as the rate of drop decreases in the vicinity of the zone where the magnetic field is applied. Temperature contours suggest that heat dissipation is directly related to the field strength. As the interaction time between the grease and heated walls of the cylinders in the channel increases due to reduced motion, better heat dissipation takes place. Velocity distribution at different locations of the channel is studied to understand the effect of magnetic field strength and rotation of cylinder walls on the flow. The velocity profile is near parabolic downstream of the magnetic zone and a higher velocity is offered by magnetorheological grease with a lower weight percentage of carbonyl iron particles.