Department of Mechanical Engineering

Indian Institute of Technology Palakkad&nbsp;(IIT Palakkad or IIT PKD) is a public autonomous&nbsp;engineering&nbsp;and&nbsp;research&nbsp;institute located in&nbsp;Palakkad,&nbsp;Kerala. It was&nbsp;one of the five new&nbsp;IITs&nbsp;proposed in the&nbsp;2014 Union budget of India. The campus was inaugurated on 3 August 2015. The institute has 94 faculty, 978 students, and 63 non-teaching staffs.

IT Palakkad currently offers four-year Bachelor of Technology (B.Tech) and two years MS programmes in 8 different engineering disciplines including&nbsp;Computer Science, Electrical, Mechanical, Civil among others.

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IIT Palakkad

World University root node

32nd ITCC/ITES, Purdue University, April 27–May 1, Indiana, USA

A Novel Technique for Estimation of Thermal Contact Conductance between Circular Bolted Joints using Inverse Heat Transfer Methodology

In a rotor-bearing system running with uniform angular acceleration, after running through the resonance, typical beat vibrations occur because the response of the system consists of the natural and excited motion. Shortly after resonance both are vibrations with frequencies close to each other. The present study explains a method for estimating damping of rotor-bearing systems from transient beat characteristics observed during the run-up stage. A mathematical justification is provided that the transient response of the rotor-bearing system consists of a beat response when the system crosses resonance. It is also clear from the mathematical model that the beat phenomenon observed depends on the level of damping in the system. The beat time period is also dependent on the angular acceleration of the system. This beat response is considered for wavelet analysis and the damping is estimated. Angular acceleration (α) of the rotor often increases the damping effects. This paper investigates how the damping ratio changes with respect to different angular acceleration values of the rotor-bearing system. Experimental validation of the beat phenomenon and damping identification is done for a rotor-bearing system. Validation for the above proposed method is done by the half-power bandwidth method of the run-up response and logarithmic decrement method of the beat response. A damping estimation from the impulse response of the stationary rotor by using wavelet transforms is also presented and validated using the logarithmic decrement method. © The Author(s) 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

JVC/Journal of Vibration and Control

Estimation of damping in rotors using complex morlet wavelet transform

Shock-wave boundary layer interaction (SWBLI) and associated changes in wall properties for ramp induced flow breakdown have been considered in the present studies. A two dimensional finite volume based CFD solver has been developed and implemented successfully to study the SWBLI. Pressure measurements are invariantly considered in the literature for qualitative prediction of various SWBLI parameters. Hence efforts are made herewith to understand the laminar boundary layer separation in the presence of ramp induced shock wave through surface heat transfer rates, wall skin friction coefficient and wall pressure distributions. Effect of variation of freestream and wall properties along with geometric changes is considered in present studies. It has been observed from present limited investigations that ratio of wall temperature to freestream stagnation temperature is the governing parameter for SWBLI instead of the individual temperatures. Increase in Mach number is found to suppress the upstream influence which results in decrease in extent of separation. Efforts are also made to study the effect of leading edge bluntness on the SWBLI. These studies are found useful to confirm the earlier reported experimental observations regarding turbulent re-attachment. © 2013 Elsevier Ltd. All rights reserved.

International Journal of Heat and Mass Transfer

Shock wave boundary layer interactions in hypersonic flows

It is with great pleasure that we bring out the twin Special Issues on Combustion in the International Journal of Advances in Engineering Sciences and Applied Mathematics (AEAM).

INTERNATIONAL JOURNAL OF ADVANCES IN ENGINEERING SCIENCES AND APPLIED MATHEMATICS

Preface

International Journal of Precision Technology 4 (3/4)

An investigation into the application of Al2O3nanofluid-based minimum quantity lubrication technique for grinding of Ti-6Al-4V

Increasing demand for precision miniaturised components made of hard and brittle materials can no longer meet the requirements by conventional machining and advanced machining processes. To facilitate high precision machining, vibration is introduced in any of workpiece, tool and working medium, which is called Vibration Assisted Machining (VAM). In this review, the advancements of VAM in conventional machining as well as in advanced machining are presented. In detail, general overview, classifications, basic kinematics of 1-D and 2-D VAM, chip formation and instrumental implementation issues of VAM, are discussed. In addition to this the reasons for improvements in machining process and promising areas to be explored in VAM are summarized. © 2014 The Authors.

Procedia Engineering

Vibration assisted conventional and advanced machining: A review

Leakage characteristics, influenced by radial growth are determined computationally for a six-tooth straight-through rotating labyrinth seal of a Gas Turbine (GT) secondary air system. The computational methodology is validated against the available data in the literature. The influence of seal location and its radial growth on the leakage performance is examined for a wide ranging speed, temperature and pressure ratios. A comparison of the structural deformations due to centrifugal and thermal effects showed that rotation has negligible effect for a smaller rotor (R25 configuration). A considerable reduction in leakage flow rate is noticed for large rotor (R75 configuration) due to both centrifugal and thermal effects.

15th International Symposium on Transport Phenomena and Dynamics of Rotating Machinery, ISROMAC 2014

Influence of location on leakage performance of a rotating labyrinth gas turbine seal with radial growth

9th International Conference on Micro Manufacturing (ICOMM)

An experimental investigation of micro-EDM drilling capability for Inconel 718 against SUS 304 stainless steel in deionized water

This study addresses the dynamic modelling and control of a novel three degrees of freedom (3-DOF) planar parallel robotic motion platform in the presence of parameter uncertainties and external disturbances. The proposed planar parallel motion platform is a guide way free manipulator and has two legs both with a revolute-prismatic-revolute (RPR) configuration located in the same plane connecting a moving platform. Of the two, one leg comprises of only one active prismatic joint, while the other leg consists of an active prismatic and an active rotary joint. The dynamic model has been derived using Euler-Lagrangian energy based formulation method. The proposed controller is based on computer torque control integrated with a disturbance observer. The disturbance vector comprising of disturbances due to parameter uncertainties, payload variations, frictional effects and further disturbances is estimated using a nonlinear disturbance observer incorporated with an extended Kalman filter (EKF). The observer uses only position and orientation measurements. Simulations with a typical trajectory are presented and compared with traditional controllers such as proportional integral derivative (PID) controller and computed torque controller and the results show that superior tracking performance is achieved in the presence of parameter uncertainties and external disturbances.

Procedia Materials Science

Dynamic Modellingand Control of a 3-DOF Planar Parallel Robotic (XY$\theta$Z Motion) Platform

In the present study, a detailed visualization of the transport of fuel film has been performed in a small carburetted engine with a transparent manifold at the exit of the carburettor. The presence of fuel film is observed significantly on the lower half of the manifold at idling, while at load conditions, the film is found to be distributed all throughout the manifold walls. Quantitative measurement of the fuel film in a specially-designed manifold of square cross section has also been performed using the planar laser-induced fluorescence (PLIF) technique. The measured fuel film thickness is observed to be of the order of 1 mm at idling and in the range of 0.1 to 0.4 mm over the range of load and speed studied. These engine studies are complemented by experiments conducted in a carburettor rig to study the state of the fuel exiting the carburettor. Laser-based Particle/Droplet Image Analysis (PDIA) technique is used to identify fuel droplets and ligaments and estimate droplet diameters. At a throttle position corresponding to idling, the fuel exiting the carburettor is found to consist of very fine droplets of size less than 15 μm and large fuel ligaments associated with length scales of the order of 500 μm and higher. For a constant pressure difference across the carburettor, the fuel consists of droplets with an SMD of the order of 30 μm. Also, the effect of liquid fuel film on the cold start HC emissions is studied. Based on the understanding obtained from these studies, strategies such as manifold heating and varying carburettor main jet nozzle diameter are implemented. These are observed to reduce emissions under both idling and varying load conditions. © 2014 Indian Academy of Sciences.