Automation is one of the trending terminologies in the field of engineering to achieve various sensors and actuators such as the hydraulic system. Smart fluid is also one of the hot topics for researchers to develop a type of actuator in many control systems since the fluid’s rheological characteristics can be controlled or tuned by the intensity of the external stimuli. In this work, a new smart fluid of magnetorheological (MR) fluid is proposed and its field-dependent rheological characteristics are experimentally identified. An MR fluid using the carrier fluid as the blend of three different fluids, namely silicon oil, honey, and organic oil is prepared. In addition, two types of natural oils are used, sunflower oil and cottonseed oil. The samples are prepared using the blend as the carrier fluid, electrolytic iron powder coated with guar gum as the dispersed phase, and oleic acid as an additive. The quantity of oleic acid is optimized for 30% by weight of electrolytic iron powder. Two samples based on sunflower and cottonseed oil are synthesized and characterized for shear viscosity and shear stress with respect to shear rate subjected to a variable magnetic field. The blend-based MR fluid shows about 10% improvement over the sedimentation rate of silicon oil-based MR fluid as compared to that to conventional MR fluid. The cottonseed oil blend-based MR fluid performs better than sunflower-based fluid in terms of the viscosity and structure.

This technical article introduces a governable brake system that can be relevant for different machines, developed using magnetorheologic (MR) fluids. As an initial step, new MR fluids are developed considering different compositions of various constituents pursued by the formulation of a numerical model considering various elements such as magnetic field strength, magnetic particle size and MR fluid yield strength. Using a commercial software, COMSOL, a magnetically energized circuit is examined to obtain the details regarding the number of turns, current supply and strength of the magnetic field at predefined points, and a simulation study is carried out. Successively, the developed and optimized MR fluid is introduced between the gap of the fixed plate and rotating disk under the influence of the magnetic field over the fluid territory. A full-fledged test rig setup for the MR brake system is established, and an experimental study is carried out focusing on the shaft speed and braking torque developed during the braking process. The results are also plotted for various current input values. The current input value ranges from 0 to 2 amp, and the respective torque value is obtained. Likewise, the performance of the torque by the proposed MR brake system used simulated results in a derived theoretical model, and a comparative study is carried out with the experimented results.

Magnetorheological (MR) fluids is synthesized using micron-sized electrolytic carbonyl iron (CI) particles and vacuum grease as additive and their rheological behaviours were investigated in terms of particle alignment by controlling magnetic field, also the effect of surfactant Triton X100 was investigated. The overall rheological characteristics and sedimentation characteristics of the synthesised samples of MR fluids were compared with Lord 132DR MR fluid using rotational Rheometer which has magnetic cell. It was establish that combination of electrolytic CI powder with vacuum grease and Triton X-100 improves the stability of the fluid by reducing sedimentation

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