Modelling the flow of an electrostructured fluid in transient operation

Abstract

This paper is primarily concerned with the feasibility of modelling the flow of electro-structured fluids (ESFs) by the use of computational fluid dynamics (CFD). The non-steady performance of specimen devices in which power, force, or torque is transmitted via an ESF is predicted. This is achieved by incorporating a Bingham plastic type model into a commercial CFD package. Adequately describing the rheology of these fluids requires the use of several parameters. The presence of plug flow and unsteady terms in the equations of motion adds a certain complexity, and a future view of including heat transfer, field distributions, and electrical conductance adds even more difficulty. For enabling practical device development/ optimization studies that incorporate these features, an approach utilizing a well-endowed CFD package for this purpose is near essential. The results are verified by experiments that represent a wide range of flow situations. For experimentation, an electrorheological (ER) fluid is used as the test medium on the grounds of convenience owing to the current availability of a reliable fluid with some characterization. However, the CFD procedures apply both to ER and to magnetorheological (MR) fluids.