Faculty Publications
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Item Influence of temperature on magnetorheological fluid properties and damping performance(IOP Publishing Ltd, 2022) Kumar Kariganaur, A.; Kumar, H.; Arun, M.The magnetorheological (MR) system's performance depends on the MR fluid's temperature in operation. This study aims to evaluate the temperature effect of MR fluid on performance while the damper is working. Before synthesizing MR fluid, scanning electron microscopy, x-ray diffraction, and particle size analysis verifies for the synthesis of MR fluid in-house. Characterization of the MR fluid at different temperatures and magnetic fields was carried out. The Herschel-Bulkley model is used to analyse the nonlinearity in the fluid by incorporating the temperature effect. The range of critical parameters used to fabricate the MR damper is selected using the Technique for Order of Preference by Similarity to Ideal Solution performance score. The temperature of the MR fluid is measured using an embedded thermocouple while the damper is operating at different loading parameters. The results reveal that the fluid temperature rises significantly from atmospheric to 125.39 °C with decrease in damping force by 66.32% at higher loading parameters. The theoretical model predicts the increase in temperature similar to that of the experimental values with an average error of 10.24% in the on-state condition. Particle characterization after dynamic testing reveals particle morphology has not changed but the saturation magnetization of the particles reduced by 57% at higher temperatures (127 °C). It is observed through thermogravimetric analysis that, the life of the fluid is reduced by 0.25%, which is negligible after dynamic testing of the fluid for approximately 85000 cycles. Finally, to imitate the temperature effect on the particle, particles were heat-Treated at 200 °C, 400 °C, and 600 °C, and through scanning electron microscope image it is confirmed that deterioration of the particle starts after 200°C, if the fluid is operated for a prolonged amount of time. © 2022 IOP Publishing Ltd.Item Study on operational temperature of magneto-rheological fluid and design dimensions of magneto-rheological damper for optimization(Institute of Physics, 2024) Kumar Kariganaur, A.; Kumar, H.; Arun, M.This study aims to restrict the upper limit for flow gap and effective length in magnetorheological (MR) damper for optimal performance. Initially, the sedimentation study of in-house MR fluid (25%) shows that an 8% reduction in the sedimentation ratio with the addition of additive and nonlinear Herschel-Bulkley (HB) model fit reflects a 32.5% decrease in average yield stress with increasing currents when the parallel plate gap is increased from 1 mm to 2 mm. Owing to this decrease in yield stress, further study is extended to fabricate two MR dampers with limit values (LV) of flow gap and effective length with a common magnetic outer cylinder. Testing results of MR dampers revealed a 72% reduction in damping force at 0.8 A current when the LV’s is increased from LV-1 to LV-2. Selecting LV-1 over LV-2 as the upper limit for any design optimization will give the MR damper optimal performance. At higher input parameters, amplitude has a 135% greater impact on damping force than frequency and current. It is also demonstrated that saturation magnetization depends on the applied magnetic field and input loading parameters. Finally, gravimetric analysis shows that the effectiveness of the MR fluid and magnetic particle starts to decline after 322 °C and 400 °C. © 2024 IOP Publishing Ltd.