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Present work optimizes the operational parameters such as solid particle diameter, inlet air velocity and inlet air temperature on heat transfer rate by Taguchi method. Operational parameters play an important role in the performance of cyclone heat exchanger thus the parameter optimization is deemed important. The parameters have been analyzed under varying solid particle diameter (300 and 400 µm), inlet air temperature (323, 373, 423 and 473 K) and inlet air velocity (5, 10, 15 and 20 m/s). Results of heat transfer rate by varying the operational parameters have been found from Computational Fluid Dynamics (CFD) software Ansys Fluent. Orthogonal array of Taguchi, the signal-to-noise ratio and analysis of variance have been employed to found the optimal parameter values and the effect of parameters on heat transfer rate. Mixed level factor and L32 array is chosen for the design of analysis in Taguchi. Result of statistical analysis shows that the developed approach yields worthy results when comparing with predicted simulation values with confidence level of 99.5%. Taguchi analysis reveals that optimized levels of parameters are 300 µm, 473 K & 20 m/s for solid particles diameter, inlet air temperature and inlet air velocity respectively. Confirmation test was conducted in simulation and experiment for optimized parameters and result shows that maximum heat transfer rate was obtained with optimized parameter among the chosen operational parameters.

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Mechanically toughened high electromagnetic interference (EMI) shielding natural rubber composite material was prepared and characterised. The aim of this investigation was to reveal the role of adding cobalt nanowire and conductive graphene nanoplatelet in toughening and EMI shielding effectiveness of rubber composite in microwave bands (E, F, I and J). The composites were prepared using two roll-mill and cured at 150 ο C. The mechanical and EMI shielding behaviour was measured following ASTM standards. The addition of graphene nanoplatelet improved the toughness and skin effect of rubber, whereas cobalt nanowire improved the magnetic permeability. A highest EMI shielding of −17.6 dB in absorption and −20 dB in reflection at 18 GHz was observed for the composite made of graphene nanoplatelet and cobalt nanowire of 3 and 8phr. These mechanically toughened promising EMI shielding composite materials could be used as EMI filters and electromagnetic wave absorbers in antennae application with good toughness.