Browsing by Author "Bhaumik, S."

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    3-Dimensional numerical study of cooling performance of a heat sink with air-water flow through mini-channel
    (2016) Majumder, S.; Majumder, A.; Bhaumik, S.
    The present microelectronics market demands devices with high power dissipation capabilities having enhanced cooling per unit area. The drive for miniaturizing the devices to even micro level dimensions is shooting up the applied heat flux on such devices, resulting in complexity in heat transfer and cooling management. In this paper, a method of CPU processor cooling is introduced where active and passive cooling techniques are incorporated simultaneously. A heat sink consisting of fins is designed, where water flows internally through the mini-channel fins and air flows externally. Three dimensional numerical simulations are performed for large set of Reynolds number in laminar region using finite volume method for both developing flows. The dimensions of mini-channel fins are varied for several aspect ratios such as 1, 1.33, 2 and 4. Constant temperature (T) boundary condition is applied at heat sink base. Channel fluid temperature, pressure drop are analyzed to obtain best cooling option in the present study. It has been observed that as the aspect ratio of the channel decreases Nusselt number decreases while pressure drop increases. However, Nusselt number increases with increase in Reynolds number. � 2016 Author(s).
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    3-Dimensional numerical study of cooling performance of a heat sink with air-water flow through mini-channel
    (American Institute of Physics Inc. subs@aip.org, 2016) Majumder, S.; Majumder, A.; Bhaumik, S.
    The present microelectronics market demands devices with high power dissipation capabilities having enhanced cooling per unit area. The drive for miniaturizing the devices to even micro level dimensions is shooting up the applied heat flux on such devices, resulting in complexity in heat transfer and cooling management. In this paper, a method of CPU processor cooling is introduced where active and passive cooling techniques are incorporated simultaneously. A heat sink consisting of fins is designed, where water flows internally through the mini-channel fins and air flows externally. Three dimensional numerical simulations are performed for large set of Reynolds number in laminar region using finite volume method for both developing flows. The dimensions of mini-channel fins are varied for several aspect ratios such as 1, 1.33, 2 and 4. Constant temperature (T) boundary condition is applied at heat sink base. Channel fluid temperature, pressure drop are analyzed to obtain best cooling option in the present study. It has been observed that as the aspect ratio of the channel decreases Nusselt number decreases while pressure drop increases. However, Nusselt number increases with increase in Reynolds number. © 2016 Author(s).
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    Active Upper Arm Exoskeleton - Design and Kinematic Analysis
    (2019) Santra, P.; Mukhopadhyay, A.; Debnath, B.; Herbert, M.A.; Bhaumik, S.
    The authors present a design of an exoskeleton with 6 active degrees of freedom (DOF) and 5 passive DOFs for rehabilitation of stroke survivors. Emphasis has been laid on making the model light weight and more ergonomic. Thus, concentration is mainly on 3D modeling of that device so that the mechatronic approach is compatible with human hand. The main choice of material for fabrication has been Nylon 6/10, owing to its lightweight and durable properties. The model was developed completely by the use of Computer Aided Design (CAD) and Computer Aided Engineering (CAE). Our model focuses on proposing a new actuation principle for better development of ergonomic shoulder design by incorporation of compliant passive springs and one passive revolute joint. Joints of the exoskeleton have been taken as simple revolute, possessing desired motion limits. Also forward kinematics has been established and the general workspace of the model has been developed. � 2019 IEEE.
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    Active Upper Arm Exoskeleton - Design and Kinematic Analysis
    (Institute of Electrical and Electronics Engineers Inc., 2019) Santra, P.; Mukhopadhyay, A.; Debnath, B.; Herbert, M.A.; Bhaumik, S.
    The authors present a design of an exoskeleton with 6 active degrees of freedom (DOF) and 5 passive DOFs for rehabilitation of stroke survivors. Emphasis has been laid on making the model light weight and more ergonomic. Thus, concentration is mainly on 3D modeling of that device so that the mechatronic approach is compatible with human hand. The main choice of material for fabrication has been Nylon 6/10, owing to its lightweight and durable properties. The model was developed completely by the use of Computer Aided Design (CAD) and Computer Aided Engineering (CAE). Our model focuses on proposing a new actuation principle for better development of ergonomic shoulder design by incorporation of compliant passive springs and one passive revolute joint. Joints of the exoskeleton have been taken as simple revolute, possessing desired motion limits. Also forward kinematics has been established and the general workspace of the model has been developed. © 2019 IEEE.
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    Wear characteristics and sustainability of WS2 solid lubricant deposited layer on Al 6061-T6 substrate under the dry sliding conditions
    (Taylor and Francis Ltd., 2023) Rajeshshyam, R.; Venkatraman, R.; Raghuraman, S.; Bhaumik, S.
    This research investigates the tribological characteristics and sustainability of WS2 deposited Al 6061-T6 surface under dry sliding conditions and optimizes the wear parameters to enhance the tribological behaviour and discuss its sustainability. The experiment used the Box–Behnken design, which examines the effective interaction between dry sliding parameters and specific wear rate (SWR) and friction coefficient (COF). By varying the load (L), sliding velocity (V) and distance (D), the wear behaviour of WS2 deposition against EN 31 steel was examined through the pin-on-disc experiment. Grooving, debris formation, polishing, tribolayer, ploughing, transfer material, smearing, delamination and pitting are observed through scanning electron microscope (SEM) analysis. For optimum conditions, SEM with energy dispersive spectroscopy was utilized to characterize the worn surface, and X-Ray diffraction (XRD) patterns confirmed the phases of W, WO3, WS2, Al, AlO, Al2S3 and Al4C3. © 2023 Institute of Materials, Minerals and Mining and Informa UK Limited, trading as Taylor & Francis Group.