Arun Nema - Academia.edu (original) (raw)

Papers by Arun Nema

International Journal of Mechanical Engineering and Technology (IJMET), 2017

A plasma wind tunnel (PWT) is used for ground testing of TPS (Thermal protection system) PWT offe... more A plasma wind tunnel (PWT) is used for ground testing of TPS (Thermal protection system) PWT offers a limited way of simulating the thermal environment on TPS materials in a limited capacity on scaled-down models. In this system, plasma is generated using the arc generator system and is made to travel at high speed through a tunnel with a nozzle at the exit. The nozzle is designed to get the required parameters at the nozzle exit. In this work, the PWT system is studied with several types of PWT and the operation envelope is studied. Operation envelops for the PWT have been found using the regression equations. The operation envelope will help in choosing a point i.e. combination of operation parameters which are to be used in testing to generate particular enthalpy and heat flux, Mach number at the nozzle exit. In the next part of this work, the supersonic nozzle design has been carried out using the method of characteristics which can be applied for designing the nozzle for the PWT for given Mach ...

International Journal of Ambient Energy, 2019

International Journal of Ambient Energy, 2019

The piston is the most important component of internal combustion engines. The piston ring contai... more The piston is the most important component of internal combustion engines. The piston ring contains a ring pack and cylinder wall. The piston ring is the moving component and it is composed of aluminium matrix composites. The aim of the work is to determine the structural and thermal stress distribution of piston rings using CATIA and ANSYS. Combustion engine pistons transform heat energy into mechanical energy by expanding gases. The thermal and structural analyses were done on the piston rings model using the properties of aluminium matrix composites (aluminium A2024 alloy and fly ash).

International Journal of Mechanical and Production Engineering Research and Development, 2018

Acoustic Emission (AE) is a naturally occurring phenomenon whereby external stimuli, such as mech... more Acoustic Emission (AE) is a naturally occurring phenomenon whereby external stimuli, such as mechanical loading, generate sources of elastic waves. AE occurs when a small surface displacement of a material is produced. These AE are generated by localized sources within the structure, which travel through the interior of the material by the shortest path and get picked up by several AE sensors placed on its surface. The Acoustic Emission NDT technique is based on the detection and conversion of these high frequency elastic waves to electrical signals. These are accomplished by directly coupling piezoelectric transducers on the surface of the structure by means of a fluid coolant and are secured with tape, adhesive bonds or magnetic hold downs. The output of each piezoelectric sensor is amplified through a low noise preamplifier, filtered to remove any extraneous noise and furthered processed by suitable electronic equipment. This project aims at studying the behavior of carbon epoxy composite materials, under loaded condition that tend to fail mainly by the following modes, namely, matrix cracking, de-lamination, fiber breakage. The specimens are tested using the acoustic emission technique and sufficient amount of data is acquired from the acoustic emission equipment. Data acquired is processed using MATLAB and various plots are then plotted. The plots between various acoustic emission parameters obtained during the experiments were analysed to understand the process of failure in carbonepoxy composite plate under tensile loading. Further the technique is applied for other specimens and data acquired is analysed to come to a strong conclusion about the behaviour of composites using the acoustic emission technique which proves to be a powerful NDT method

International Journal of Mechanical and Production Engineering Research and Development, 2018

This research paper concerns to optimize the various aerodynamic characteristics of the vehicle t... more This research paper concerns to optimize the various aerodynamic characteristics of the vehicle to reduce the drag resistance and to increase the fuel efficiency and vehicle performance. Nowadays, fuel consumption of the vehicle is the major problem to deal. So, to reduce the fuel consumption and to improve the fuel economy, aerodynamic drag resistance will be considered and minimized. In this project, the drag resistance of the vehicle will be reduced by using the rear spoiler. The spoiler is designed for achieving the best result in reducing the drag in a hatchback car model. The scaled model of the car is created by using the software CATIA V5R20. The spoiler also designed using this software. The Computational Fluid Dynamics (CFD) simulation and analysis is done on the scaled modeled car with the spoiler by using ICEM CFX. The correlation between the without and with spoiler arrangements on the scaled model car is also investigated.

International Journal of Mechanical Engineering and Technology (IJMET), 2017

A plasma wind tunnel (PWT) is used for ground testing of TPS (Thermal protection system) PWT offe... more A plasma wind tunnel (PWT) is used for ground testing of TPS (Thermal protection system) PWT offers a limited way of simulating the thermal environment on TPS materials in a limited capacity on scaled-down models. In this system, plasma is generated using the arc generator system and is made to travel at high speed through a tunnel with a nozzle at the exit. The nozzle is designed to get the required parameters at the nozzle exit. In this work, the PWT system is studied with several types of PWT and the operation envelope is studied. Operation envelops for the PWT have been found using the regression equations. The operation envelope will help in choosing a point i.e. combination of operation parameters which are to be used in testing to generate particular enthalpy and heat flux, Mach number at the nozzle exit. In the next part of this work, the supersonic nozzle design has been carried out using the method of characteristics which can be applied for designing the nozzle for the PWT for given Mach ...

International Journal of Ambient Energy, 2019

International Journal of Ambient Energy, 2019

The piston is the most important component of internal combustion engines. The piston ring contai... more The piston is the most important component of internal combustion engines. The piston ring contains a ring pack and cylinder wall. The piston ring is the moving component and it is composed of aluminium matrix composites. The aim of the work is to determine the structural and thermal stress distribution of piston rings using CATIA and ANSYS. Combustion engine pistons transform heat energy into mechanical energy by expanding gases. The thermal and structural analyses were done on the piston rings model using the properties of aluminium matrix composites (aluminium A2024 alloy and fly ash).

International Journal of Mechanical and Production Engineering Research and Development, 2018

Acoustic Emission (AE) is a naturally occurring phenomenon whereby external stimuli, such as mech... more Acoustic Emission (AE) is a naturally occurring phenomenon whereby external stimuli, such as mechanical loading, generate sources of elastic waves. AE occurs when a small surface displacement of a material is produced. These AE are generated by localized sources within the structure, which travel through the interior of the material by the shortest path and get picked up by several AE sensors placed on its surface. The Acoustic Emission NDT technique is based on the detection and conversion of these high frequency elastic waves to electrical signals. These are accomplished by directly coupling piezoelectric transducers on the surface of the structure by means of a fluid coolant and are secured with tape, adhesive bonds or magnetic hold downs. The output of each piezoelectric sensor is amplified through a low noise preamplifier, filtered to remove any extraneous noise and furthered processed by suitable electronic equipment. This project aims at studying the behavior of carbon epoxy composite materials, under loaded condition that tend to fail mainly by the following modes, namely, matrix cracking, de-lamination, fiber breakage. The specimens are tested using the acoustic emission technique and sufficient amount of data is acquired from the acoustic emission equipment. Data acquired is processed using MATLAB and various plots are then plotted. The plots between various acoustic emission parameters obtained during the experiments were analysed to understand the process of failure in carbonepoxy composite plate under tensile loading. Further the technique is applied for other specimens and data acquired is analysed to come to a strong conclusion about the behaviour of composites using the acoustic emission technique which proves to be a powerful NDT method

International Journal of Mechanical and Production Engineering Research and Development, 2018

This research paper concerns to optimize the various aerodynamic characteristics of the vehicle t... more This research paper concerns to optimize the various aerodynamic characteristics of the vehicle to reduce the drag resistance and to increase the fuel efficiency and vehicle performance. Nowadays, fuel consumption of the vehicle is the major problem to deal. So, to reduce the fuel consumption and to improve the fuel economy, aerodynamic drag resistance will be considered and minimized. In this project, the drag resistance of the vehicle will be reduced by using the rear spoiler. The spoiler is designed for achieving the best result in reducing the drag in a hatchback car model. The scaled model of the car is created by using the software CATIA V5R20. The spoiler also designed using this software. The Computational Fluid Dynamics (CFD) simulation and analysis is done on the scaled modeled car with the spoiler by using ICEM CFX. The correlation between the without and with spoiler arrangements on the scaled model car is also investigated.