i-manager's Journal on Mechanical Engineering (JME)


Volume 12 Issue 2 February - April 2022

Research Paper

Exergy Investigation of Home Air Conditioner Working with Different Environment Friendly Refrigerants

Faraj El-Sagier* , Mohammed Ali Elhaj Umbarek**
*-** Department of Mechanical and Industrial Engineering, Faculty of Engineering, University of Tripoli, Libya.
El-Sagier, F., and Umbarek, M. A. E. (2022). Exergy Investigation of Home Air Conditioner Working with Different Environment Friendly Refrigerants. i-manager’s Journal on Mechanical Engineering, 12(2), 1-9. https://doi.org/10.26634/jme.12.2.18383

Abstract

In this paper, the performance of various alternative refrigerants were compared to find the replacement for R22, the widely used hydrochlorofluorocarbon (HCFC) refrigerant in home air conditioning systems in most developing countries. This study include the environment friendly hydrofluorocarbon (HFC) refrigerants such as R-134a, R-410A, R-407C and R- 404A. A steady state thermodynamic modelling and simulation of a home air conditioner as an actual vaporcompression system was developed. The model predicted the performance of the system with the mentioned alternative refrigerants in terms of energy and exergy. Based on design conditions, operating parameters, such as coefficient of performance (COP), energy efficiency rating (EER), exergy efficiency (η11) and exergy destruction ratio (EDR) were evaluated. The results obtained showed that R-134a, R-410A, R407C, and R-404A are better substitute to replace R22, as they are more environment friendly air conditioning cooling applications.

Research Paper

Experimental Analysis on Heat Exchanger using Al2O3-CuO Hybrid Nano Coolant

V. Kranti Raj Sameer* , A. Swarna Kumari**
* CSIR-Central Mechanical Engineering Research Institute, Durgapur, West Bengal, India.
** Department of Mechanical Engineering, Jawaharlal Nehru Technological University, Kakinada, Andhra Pradesh, India.
Sameer, V. K. R., and Kumari, A. S. (2022). Experimental Analysis on Heat Exchanger using Al2O3-CuO Hybrid Nano Coolant. i-manager’s Journal on Mechanical Engineering, 12(2), 10-21. https://doi.org/10.26634/jme.12.2.18474

Abstract

This research work gives the insight on heat transfer performance of nano coolants using hybrid nanoparticles Al2O3-CuO in mixture ratio 20:80, 50:50, 80:20 respectively, at 0.1 vol% of 5 liter base fluid (mono ethylene glycol (MEG)+ deionized water (DW)) on a double pipe shell and tube heat exchanger. Nanoparticles were prepared using ball milling, magnetic stirring and ultra-sonication. The average diameter of crystallites of hybridized nanoparticles was in the range of 25 nm to 35 nm, determined using an X-ray diffractometer. Specific heat capacity, density and kinematic viscosity were determined using differential scanning calorimetry, Redwood viscometer and precision balance, respectively. Modifications were done on the cold side of the heat exchanger by installing a tank at the top for the nano coolant. The flow rates on cold fluid side was fixed to 1.2 L/min and hot fluid side varied from 0.6 L/min to 1.2 L/min operated on both, parallel flow and counter flow arrangement. Coolant sample 80:20 (Al2O3:CuO) amongst all the samples possessed highest rate of effectiveness with an increment of 35% when compared to traditional sample DW + MEG and also with water. Highest logarithmic mean temperature difference (LMTD) and overall heat transfer coefficient (OHTC) were observed for the above sample. Smidgen amount of agglomeration had been observed while conducting the experiment.

Research Paper

Parametric Analysis of Entropy Generation in Turbulent Convective Forced Flow in Spiral Channels at Constant Wall Temperature

Faraj El-Sagier*
Department of Mechanical Engineering, University of Tripoli, Libya.
El-Sagier, F. (2022). Parametric Analysis of Entropy Generation in Turbulent Convective Forced Flow in Spiral Channels at Constant Wall Temperature. i-manager’s Journal on Mechanical Engineering, 12(2), 22-32. https://doi.org/10.26634/jme.12.2.18387

Abstract

This paper discuses parametric analysis of entropy generation in a forced convective turbulent flow of an incompressible fluid at a constant wall temperature through spiral channel of rectangular cross section of flow path has been carried out in terms of mass flow rates, temperature differences between fluid flow and temperature of the wall of the passage surface, width of the spiral passages and the shape geometry, as well as the types of fluids. Air is used as the working fluid, and in addition, water and oil are used in the parametric study. The competition between heat transfer enhancement and entropy generation has been addressed. Comparison between entropy generation profiles for different passage widths and shapes have been reported. It is found that mass flow rate and inlet fluid temperature have a considerable impact on entropy generation and hence on heat transfer enhancement. The findings show that the narrowing passage consumes more pump power to overcome viscous dissipation. Regarding the channel shape, it was found that the rectangular channel has the highest Bejan number (Be), while the circular spiral channel requires more pump power than the others. The data obtained indicate that the selection of the most suitable configuration and the best flow conditions becomes a critical task. Also, secondary flow due to centrifugal force and curvature has a significant effect on increasing heat transfer and entropy generation.

Research Paper

Analysis of a Finned Type Concentric Tube Heat Exchanger using Different Materials by Applying CFD

Jithendra Sai Raja Chada* , Ganesh Nathipam**, Dharmalingam R.***
* NS Engineering Company Pvt Ltd, Hyderabad, Telangana, India.
**-*** Department of Mechanical Engineering, Pragati Engineering College, Surampalem, Andhra Pradesh, India.
Chada, J. S. R., Nathipam, G., and Dharmalingam, R. (2022). Analysis of a Finned Type Concentric Tube Heat Exchanger using Different Materials by Applying CFD. i-manager’s Journal on Mechanical Engineering, 12(2), 33-39. https://doi.org/10.26634/jme.12.2.18476

Abstract

Heat exchangers are equipment used to transfer heat from a high temperature fluid to a low temperature fluid without direct contact. Usually, the heat exchangers used for industrial applications are large in size. The objective of this study is to reduce the size of the heat exchanger and increasing the effectiveness by using suitable materials. The present study is carried out on a concentric tube heat exchanger with rectangular fins arranged around the circumference of the tube. The initial simulation is carried out to find the best material among aluminum bronze and Al 6061. The study is further continued to find the best inlet conditions by varying the mass flow rate from 0.25 kg/s to 3 kg/s in 0.25 kg/s increments and inlet temperature from 80°C to 90°C in 5°C increments. Cold water flow conditions, such as mass flow rate of 1.5 kg/s and inlet temperature of 30°C, are constant throughout the study. The heat exchanger was modeled in SOLIDWORKS 2020. The flow simulation and thermal analysis were carried out in SOLIDWORKS Flow Simulation 2020. The simulation results and the actual prototype results showed a variation of 4.2%.

Research Paper

Multi Objective Optimization of 3D Printing Process using Multi-Attribute Decision Making Methods

V. Chengal Reddy * , S. Kavitha**, T. Nishkala***, S. M. Jameel Basha****
*-**** Department of Mechanical Engineering, Chadalawada Ramanamma Engineering College, Tirupati, Andhra Pradesh, India.
Reddy, V. C., Kavitha, S., Nishkala, T., and Basha, S. M. J. (2022). Multi Objective Optimization of 3D Printing Process using Multi-Attribute Decision Making Methods. i-manager’s Journal on Mechanical Engineering, 12(2), 40-49. https://doi.org/10.26634/jme.12.2.18562

Abstract

Fused deposition modeling (FDM) is one of the additive manufacturing (AM) methods widely used in many divisions, especially medical implants and aerospace, due to capabilities to build complex 3D objects and geometries. However, quality and dimensional accuracy of the FDM parts are significantly influenced by the various FDM process parameters including filament wire material. In the present work, new filament wire material Thermoplastic Polyurethane (TPU) was utilized to produce FDM parts. Hence, deciding the optimum process parameters is very critical to produce the FDM parts with good surface quality (Ra) and dimensional accuracy (Δd) concurrently using TPU material. In this paper, the author has contributed to determine the optimum 3D printing process parameters to improve the quality and accuracy for the new filament wire material Thermoplastic Polyurethane (TPU) using multi-attribute decision making (MADM) methods namely Gray Relational Analysis (GRA) and technique for order preference by similarity to ideal solution (TOPSIS). Further, the results of GRA and TOPSIS techniques were compared and concluded that TOPSIS method substantially reduced the surface roughness to a value of 12% contrast to the GRA method whereas the dimensional deviation accuracy increased to 6.25% over the GRA method.

Research Paper

A Study on Design and Analysis by Varying Piston Material in SI Engine

Sri Ram Deepak Akella* , Sashendra Srinivas Baswanth Pappula**, Sanku Sai Aditya Vardhan***, Alluri Sujatha Priyadarshini****
*-****Department of Mechanical Engineering, Pragati Engineering College, Surampalam, Andhra Pradesh, India.
Akella, S. R. D., Pappula, S. S. B., Vardhan, S. S. A., and Priyadarshini, A. S. (2022). A Study on Design and Analysis by Varying Piston Material in SI Engine. i-manager’s Journal on Mechanical Engineering, 12(2), 50-61. https://doi.org/10.26634/jme.12.2.18576

Abstract

The piston in an internal combustion engine is exposed to high temperature and pressure for a long time. Generally, when designing a piston, the material used must have a high melting point and tensile strength. In this paper, the design research and structural analysis of the piston of a four-stroke spark ignition (SI) engine was carried out by changing the composition of the piston material with various materials such as titanium alloy, magnesium alloy, gray cast iron, aluminum alloy and structural steel. The study investigated mechanical strain and the mechanical stress, deformation, heat dissipation, and heat-flux. This study concluded that under assumed conditions, depending on other piston parameters, titanium alloy creates optimal conditions for the piston.