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


Volume 13 Issue 4 October - December 2023

Research Paper

Effects of Drill Pipe Length and Weight on Bit on Lateral and Longitudinal Vibrations

Borerwe Andrew Zivai* , Mupfumira Portia**, Ndala Emmanuel***
*-*** Harare Institute of Technology.
Zivai, B. A., Portia, M., and Emmanuel, N. (2023). Effects of Drill Pipe Length and Weight on Bit on Lateral and Longitudinal Vibrations. i-manager’s Journal on Mechanical Engineering, 13(4), 1-12. https://doi.org/10.26634/jme.13.4.20076

Abstract

The vibration of a drill string is the topic under study in drilling and mining engineering. Drill string vibrations cause early failure of bits due to fatigue, drill pipe fracture and bearings damage. A modal and harmonic vibrational analysis of a drill string up to 60-65m long was done in a vertical water well by carrying out parametric studies. This paper investigates vibration of a drill string under longitudinal and mainly lateral which is the most dominant under the action of parameters such as drill pipe lengths and weight on bit. Finite element modelling of a drill string was made in Ansys workbench 2020, mechanical. Modal and harmonic frequencies were determined to obtain optimal drill pipe length and possible weight on bits. The drilling environment was assumed by using different weights on bit.

Research Paper

Shell Tube Exchanger Parametric Investigation and Performance Simulation using Ansys

Malik F. Elmzughi* , Mohammed A. Elhaj**, Elhadi I. Dekam***
*-*** Mechanical and industrial Engineering Department, Faculty of Engineering, University of Tripoli, Tripoli, Libya.
Elmzughi, M. F., Elhaj, M. A., and Dekam, E. I. (2023). Shell Tube Exchanger Parametric Investigation and Performance Simulation using Ansys. i-manager’s Journal on Mechanical Engineering, 13(4), 13-21. https://doi.org/10.26634/jme.13.4.20072

Abstract

Heat exchangers with shells and tubes are widely employed in the chemical, power generating, and petroleum refining industries. A three-dimensional simulation of a shell and tube heat exchanger with segmental baffles was performed in this paper. The research involves the use of commercial code such as ANSYS CFX, MATLAB, and Solid-Work, which incorporate modeling, meshing, and the use of finite element techniques to produce numerical results. The results have been achieved in transient situations. The purpose of this paper is to optimize and analyze temperature drops, pressure drops in side shells and tubes, stream-by-stream velocities, and parametric investigations such as the number of baffles, the distance between baffles, and the number of passes using the ANSYS program. The pressure drop that has been addressed shows that raising the baffle cut and reducing the baffle spacing have opposite impacts on the pressure drop. In many cases, the pressure drop on the shell and tube sidewalls was investigated as well. Pressure drop has been investigated in terms of the number of baffles, the gap between baffles, and the number of passes.

Research Paper

Fatigue Life Prediction of Aluminum 6061 Alloy through Experimental and Numerical Analysis under Various Stress Ratios in Axial Tension-Tension Loading Condition

K. Krishna Bhaskar* , K. Janaki Ramaiah**, K. Meera Saheb***, V. Kalyana Manohar****, T. Lakshman Kishore*****
*-***** Department of Mechanical Engineering, University College of Engineering Kakinada (A), Andhra Pradesh, Kakinada, India.
Bhaskar, K. K., Ramaiah, K. J., Saheb, K. M., Manohar, V. K., and Kishore, T. L. (2023). Fatigue Life Prediction of Aluminum 6061 Alloy through Experimental and Numerical Analysis under Various Stress Ratios in Axial Tension-Tension Loading Condition. i-manager’s Journal on Mechanical Engineering, 13(4), 22-33. https://doi.org/10.26634/jme.13.4.20198

Abstract

Aluminum alloy 6061 is a versatile material widely used in aerospace, automotive, marine, and structural applications due to its mechanical strength, weldability, and corrosion resistance. Understanding and addressing fatigue is crucial for ensuring the reliable and safe performance of components made from this alloy. This study focused on predicting the fatigue life of aluminum 6061 at room temperature under axial loading conditions and evaluating the fatigue life at various stress ratios. The experimental S-N curve, derived from tension-tension fatigue loading tests, was instrumental in characterizing the material's fatigue behaviour under constant amplitude loading condition. The data obtained from these tests were then imported into ANSYS software, a widely recognized tool for finite element analysis and simulation. ANSYS was used to conduct a detailed numerical analysis to predict the fatigue life of aluminum 6061 at different stress ratios. The results from the experimental and numerical analyses exhibited good agreement, validating the accuracy of ANSYS software in predicting fatigue life at different stress ratios. This study demonstrated the effectiveness of employing a combined experimental and numerical approach for understanding fatigue behaviour in materials, particularly in terms of its applicability to different loading scenarios. The findings from this research provide valuable insights into the fatigue life of aluminum 6061 under diverse stress ratios, with the goal of enhancing material design and engineering processes. By leveraging the capabilities of ANSYS software in conjunction with experimental data, the study established a reliable methodology for predicting fatigue life, which is crucial for optimizing the performance and longevity of components subjected to cyclic loading in various industries.

Research Paper

Enhancing the Control of Boron Epoxy Cross-Ply Laminated Composite Plates through Intelligent Implementation of PZT Sensor and Actuator

Dileep Kumar K* , M. Lova Kumari**
* Jawaharlal Nehru Technological University, Kakinada, Andhra Pradesh, India.
** K L Deemed to be University, Andhra Pradesh, India.
Kumar, K. D., and Kumari, M. L. (2023). Enhancing the Control of Boron Epoxy Cross-Ply Laminated Composite Plates through Intelligent Implementation of PZT Sensor and Actuator. i-manager’s Journal on Mechanical Engineering, 13(4), 34-40. https://doi.org/10.26634/jme.13.4.20321

Abstract

Piezoelectric materials find diverse applications in structural engineering, particularly in fields like condition monitoring, smart control, and testing. The captivating interplay between their mechanical and electrical properties has garnered significant attention, showcasing immense potential for practical utility. Notably, these materials boast costeffectiveness, lightweight characteristics, compact size, exceptional dynamic capabilities, swift responsiveness, enduring stability, and remarkable energy conversion efficiency. In our research initiative, we delve into a study concentrated on the symmetric surface attachment of two piezoelectric patches or actuators onto composite laminate plates. The goal is to induce a bending effect in the laminate by applying equal-magnitude electric voltages with opposite polarities to these symmetrically positioned piezoelectric actuators. The determination of the bending moment involves the application of principles related to elasticity and piezoelectricity. To scrutinize the displacement and natural frequency of the composite plate influenced by this bending moment, we utilize plate theory and derive analytical solutions. Furthermore, these piezoelectric patches, affixed to the composite laminate plate's surface, double as vibration actuators. We subject the plate to loads to investigate its vibration response in a simply supported rectangular configuration. This excitation is achieved by applying time-harmonic voltages to the piezoelectric patches. Throughout our study, we compute analytical solutions for both deflection and vibration amplitude, presenting numerical results that depict the static deflection and vibration amplitude of the plate. Additionally, a parametric study is conducted to elucidate the influence of piezoelectric actuator size and placement on cross-ply composite laminate plates.

Review Paper

Ball Mill Energy Efficiency Optimization Techniques: A Review

Laurence Maregedze * , Rujeko Masike **, Tatenda Kanyowa***, Kudzanayi Chiteka****
* Department of Fuels and Energy Engineering, Midlands State University, Zimbabwe.
**-*** Department of Industrial and Manufacturing Engineering, Harare Institute of Technology, Zimbabwe.
**** School of Engineering and the Built Environment, University of South Africa, South Africa.
Maregedze, L., Masike, R., Kanyowa, T., and Chiteka, K. (2023). Ball Mill Energy Efficiency Optimization Techniques: A Review. i-manager’s Journal on Mechanical Engineering, 13(4), 41-50. https://doi.org/10.26634/jme.13.4.20053

Abstract

Ball mills are essential machinery in the mining industry, thermal power-producing companies, and cement manufacturing companies, for grinding different ores, grinding coal into pulverized coal, and processing cement clinkers into fine powder cement or pulp. Their design operational and energy inefficiencies are because of drivetrain inefficiencies, output load rerun, lifter face angle configuration, and poor load classifiers, with energy inefficiency topping the list of inefficiencies. These inefficiencies bring about lower production rates and huge energy costs aggravating lower profit margins. Notably, out of the total energy consumed by a ball mill, only 1% is used productively for grinding purposes while the bulk, over 80% of the energy is wasted in heat generation and carried away by the slurry or dissipated into the atmosphere. Numerous design innovations have been done on ball mills but these inefficiencies still persist, hence the need to further design an energy-efficient ball mill for industrial use. This review sought to outline and discuss the ball mill energy efficiency optimization methods which had been very limitedly explored by most researchers. There is a need to determine the ball mill energy waste by carrying out practical experiments and simulations using CFDDEM analysis.