National Institute of Technology, Meghalaya

About: National Institute of Technology, Meghalaya is a education organization based out in Shillong, India. It is known for research contribution in the topics: Control theory & Electric power system. The organization has 503 authors who have published 1062 publications receiving 6818 citations. The organization is also known as: NIT Meghalaya & NITM.

Unsteady MHD Chemically Reacting and Radiating Mixed Convection Slip Flow Past a Stretching Surface in a Porous Medium

Abstract: This paper studies the effects of combined buoyancy forces, thermal radiation, chemical reaction, velocity slip, magnetic field and porous medium permeability on unsteady mixed convection flow of electrically conducting fluid past a stretching sheet embedded in a porous medium. Appropriate governing equations are procured and also reduced to set of nonlinear coupled ordinary differential equations by means of suitable similarity transformations. The boundary valued problem is numerically tackled using the fourth-fifth order Runge-Kutta-Fehlberg integration approach with shooting outline. Various controlling parameters effects on the fluid velocity, temperature and kinds concentration profiles together with local skin friction, Nusselt number and Sherwood number are presented diagrammatically and deliberated upon quantitatively. It is found that buoyancy forces increment enhance both heat and mass transfer rate while thermal and concentration boundary layer denseness diminished.

Modeling and validation of a 2-DOF parallel manipulator for pose control application

Abstract: Simplified mathematical model for the hydraulically actuated 2DOF parallel manipulator has been developed.In the present mathematical modeling, system kinematics, dynamics along with joint friction have been considered.The model has been implemented in MatlabSimulink environment and has been verified with the experimental result.Fuzzy tuned feedforward PID bias controller has been developed for control analysis of the system. Control performance has been studied for different pose demand and external loading condition. The use of hydraulically actuated parallel manipulator in different industries increasing rapidly due to high rigidity, higher accuracy, less error propagation, fast speed of response, very good controllability, high power to weight ratio, self lubricating property, heat dissimilation characteristic etc. Manipulator with low degree of freedom (DOF) is simple to analysis, synthesis and fabrication compare to the higher DOF manipulator. In the present work hydraulically actuated 2DOF parallel manipulator has been considered for simulation study of the pose (heave and pitch) control application. Low cost hydraulic component (proportional valve with dead band, low speed hydraulic cylinder etc.) configuration has been considered for the system model. In the present study the simplified mathematical model of the manipulator has been developed. The model of the parallel manipulator has been verified with the experimental result. The verified model has been used to study the control performance by a model free fuzzy tuned feedforward bias PID controller for pose control application. The effectiveness of the proposed controller also has been studied. To study the robustness of the proposed controller central, eccentric and variable position of the external loading has been considered on the manipulator with sinusoidal and chirp heave and pitch demand.

Second law analysis of the flow of two immiscible micropolar fluids between two porous beds

Abstract: This work investigates the effect of entropy generation rate within the flow of two immiscible micropolar fluids in a horizontal channel bounded by two porous beds at the bottom and top. The flow is considered in four zones. Zone IV contains the flow of viscous fluid in the large porous bed at the bottom, zone I and zone II contain the free flow of two immiscible micropolar fluids, and zone III contains the flow of viscous fluid in the thin porous bed at the top. The flow is assumed to be governed by Eringen’s micropolar fluid flow equations in the free channel. Darcy’s law and Brinkman’s model are used for flow in porous zones, namely, zone IV and zone III, respectively. The closed form expressions for entropy generation number and Bejan number are derived in dimensionless formby using the expressions of velocity, microrotation and temperature. The effect of physical parameters like a couple stress parameter and micropolarity parameter on velocity, microrotation, temperature, entropy generation number and Bejan number are investigated.