Article
Engineering, Mechanical
Krishnkant Sahu, Satish C. Sharma, Adesh Kumar Tomar
Summary: This paper proposes a study on the slot-entry 'hybrid conical journal bearing system' (HCJBs) with the slot restrictor as a compensating device. The effects of different zonal arrangements of textured surfaces and smart behavior of magnetorheological fluid (MRF) on the HCJBs are analyzed. Mathematical modeling of the modified Reynolds equation is done using the Finite element method and the Gauss-Seidel method. Numerical simulation shows that the application of textured surfaces and MR fluid improves the performance of the hybrid conical bearing system in terms of fluid film thickness, stiffness, and stability.
TRIBOLOGY INTERNATIONAL
(2023)
Article
Engineering, Mechanical
Satish C. Sharma, Narendra Kumar
Summary: This paper discusses the behavior of a hybrid circular thrust pad bearing (HCTB) lubricated with ER and having three-dimensional surface irregularities. Finite element analysis is used to solve the Reynolds equation and the orifice restrictor equation to study the behavior of the bearing. The use of ER lubricant and consideration of 3D surface irregularities result in improved load capacity and damping coefficient, but reduced stiffness coefficient of HCTB.
TRIBOLOGY INTERNATIONAL
(2023)
Article
Engineering, Mechanical
Satish C. Sharma, Nitin Agrawal
Summary: This article presents the finite element modeling of a spherical hybrid thrust bearing, considering the influence of three-dimensional surface irregularities and magnetorheological lubricant behavior. The study shows that by considering the surface irregularities and operating with MR fluid, the performance of the bearing is improved, but this improvement comes at the cost of power loss due to viscous friction.
TRIBOLOGY TRANSACTIONS
(2022)
Article
Optics
Jicheng Chen, Fengye Tang, Yanhong Wei, Longgen Qian, Yifeng Tang
Summary: This paper investigates the effects of edge misalignment on the dynamic behavior of weld pool by developing a multi-phase CFD model. Both experimental and numerical simulations are conducted considering different scales of edge misalignment. The results show that the keyhole quickly penetrates the workpiece and the flow patterns within the weld pool are driven by recoil pressure, surface tension gradient, and gravity. Moreover, the size of the weld pool shrinks as the sheet edges become more misaligned.
OPTICS AND LASER TECHNOLOGY
(2023)
Article
Engineering, Mechanical
Krishnkant Sahu, Satish C. Sharma, Adesh Kumar Tomar
Summary: The present article investigates the effects of deformable bearing shells and electrorheological lubricant on the performance of lobed slot-entry hybrid journal bearing systems. The results show that considering deformation in the bearing shells improves the bearing performance, while the use of electrorheological lubricant increases the lubricating film thickness and stability.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART J-JOURNAL OF ENGINEERING TRIBOLOGY
(2023)
Article
Multidisciplinary Sciences
Nathan B. Speirs, Kenneth R. Langley, Zhao Pan, Tadd T. Truscott, Sigurdur T. Thoroddsen
Summary: The study found that when a solid object impacts a liquid surface, cavitation can occur in the liquid, leading to a decrease in local pressure. Large pressure waves created by the impact reflect back from the free surface to create negative pressure regions, with cavitation potentially happening at relatively low impact velocities. This research suggests that localized cavitation could occur in various impact scenarios such as boat slamming, cliff jumping, and ocean landing of spacecraft.
NATURE COMMUNICATIONS
(2021)
Article
Engineering, Marine
Di Yingtang, Zhao Lanhao, Mao Jia, Avital Eldad
Summary: The proposed resolved CFD-DEM-IBM algorithm provides a detailed numerical description of water entry process using Navier-Stokes equations, discrete element method (DEM), and immersed boundary method (IBM). The algorithm demonstrates reliability and versatility in modeling interactions among heterogeneous fields for more general problems.
Article
Mechanics
Q. Zhang, Z. Zong, H. T. Li, T. Z. Sun
Summary: In this paper, an experimental study on the cavity evolution behind a hydrophobic sphere entering water is conducted. It is found that splash and cavity evolution are correlated. Two dominant regimes for cavity pinch-off, hydrostatic pressure and pressure pulsation inside the cavity, are confirmed. The impact of the splash closure on the necking position is dependent on the Froude number, with a critical value separating deep pinch-off into two regimes. The theoretical model is consistent with experimental results, except when the splash occurs and the effect of pressure pulsation inside the closed cavity increases.
Article
Mechanics
Mahsa Janati, Amir Hossein Azimi
Summary: The water entry, crown formation, and cavity dynamics of gravity-driven thick solid and annular disks were studied through laboratory experiments. Various parameters including aspect ratio, geometry, and density of disks were investigated to determine their effects on crown formation, interface impact, seal development, and air entrainment. Four crown shapes were identified and classified based on dimensionless moment of inertia and impact Froude number. The experiments also showed that high-density disks form deeper seals and have larger pinch-off depth in the ambient water. The velocities and vortex fields of the disks were measured and analyzed, revealing differences between solid and annular disks and the influence of release conditions.
Article
Thermodynamics
Ketan Yogi, Shankar Krishnan, S. V. Prabhu
Summary: The local heat transfer distribution is measured for a flat plate with a porous metal foam subjected to a rectangular slot air jet. The study aims to separate the effects of convection and conduction heat transfer in the flat plate with metal foam. The thickness of the metal foam and the impinging distance of the jet are varied to investigate their influence on heat transfer. Results show that the presence of metal foam reduces convective heat transfer but enhances conduction heat transfer. The thickness of the metal foam affects the hydraulic resistance experienced by the impinging jet. Overall, the enhancement of conduction heat transfer dominates over the attenuation of convective heat transfer.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2022)
Article
Mechanics
M. Sakthivel, Kameswararao Anupindi
Summary: This study develops a three-dimensional characteristic-based off-lattice Boltzmann method to handle non-uniform meshes in blood flow simulation of stenosed arteries. The solver is validated and applied to study blood flow through irregular arterial stenosis. The results show that the shape of stenosis has a significant impact on blood flow dynamics.
Article
Engineering, Multidisciplinary
Jiaojiao Ma, Chao Fu, Hao Zhang, Fulei Chu, Zhanqun Shi, Fengshou Gu, Andrew D. Ball
Summary: This study investigates the coupling effects of non-Gaussian properties and misalignments on the performance of journal bearings, finding that non-Gaussian rough surfaces have a more significant influence on static performance, with negative skewness and large kurtosis increasing load capacity and decreasing friction coefficient. Non-Gaussian properties have a greater impact on performance than misalignment in hydrodynamic lubrication regime.
Article
Automation & Control Systems
Yiheng Chen, Xiaoting Rui, Yuanyuan Ding, Yu Chang, Hanjing Lu
Summary: This study established a machining system model with misaligned coupling and investigated the influence of spindle vibration on machining quality. It found abundant low-order harmonics in the vibration response, with the angular vibration of the spindle being particularly significant in affecting the machined surface.
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2022)
Article
Computer Science, Hardware & Architecture
Gieun Kim, Jeongpil Na, Mose Jung, Jongwoon Park
Summary: In this study, we optimized the structure of slot-die heads for achieving highly uniform large-area organic thin films for potential applications in OLEDs. Computational fluid dynamics simulation was used to analyze the pressure and velocity distributions inside the cavity by varying the structure parameters. The maximum shim thickness was derived from the simulation results, providing a design guideline. We successfully coated low-viscosity and high-viscosity materials and achieved thin films with good thickness uniformity. OLED devices were fabricated with the coated PEDOT:PSS layer, showing promising performance.
Article
Thermodynamics
Muhammad Waris Saeed Khan, Zeeshan Asghar, Khalil Ur Rehman, Wasfi Shatanawi
Summary: This study solves the heat conduction equation problem with non-homogeneous boundary conditions using the superposition principle and separation of variable approach. The MATLAB algorithm is used to calculate eigenvalues and related eigenfunctions. The simplified Phan-Thien-Tanner (SPTT) fluid and finite extendable non-linear elastic peterline (FENE-P) fluid models are also discussed.
CASE STUDIES IN THERMAL ENGINEERING
(2023)
Article
Engineering, Mechanical
Satish C. Sharma, Krishnkant Sahu
Summary: The study showed that the use of a ferrofluid lubricant can provide optimized lubricant film parameters, including lubricant film thickness and fluid film stiffness/damping coefficient, as well as a better stability threshold speed.
PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART J-JOURNAL OF ENGINEERING TRIBOLOGY
(2021)
Article
Materials Science, Multidisciplinary
Aasiya Parveen, Nathi Ram Chauhan, Mohd Suhaib
Summary: Aluminium hybrid composites (AHCs) were developed in this study using powder metallurgy method, with varying weight percentages of Si3N4 and ZrO2 reinforcements. The SEM results showed uniform distribution of reinforcement and matrix particles, with accumulation of nano-size ZrO2 particles. With increasing compaction pressure and weight percentages of reinforcements, density and micro-hardness improved while porosity decreased. The highest hardness value was found to be 72 VHN for sample E at 500 MPa.
ADVANCES IN MATERIALS AND PROCESSING TECHNOLOGIES
(2022)
Article
Metallurgy & Metallurgical Engineering
A. Parveen, N. R. Chauhan, M. Suhaib
Summary: In this study, aluminum hybrid composites were developed through powder metallurgy using Si3N4 and ZrO2 as reinforcements. The impact of milling time and reinforcement weight percentage on microstructure, density, and hardness was investigated. The results showed that homogeneous mixing of reinforcements with the matrix and reduction of clusters were observed with increased milling time, leading to increased density and hardness of the composites.
PHYSICS OF METALS AND METALLOGRAPHY
(2021)
Article
Materials Science, Multidisciplinary
Sakshi Singh, Nathi Ram Chauhan
Summary: This study investigates the wear behavior and parameters of B4C/AZ91DMg metal matrix composites prepared by a vacuum-based stir casting process. The results show the uniform dispersion of B4C in the composites and the occurrence of severe delamination under high load conditions. Statistical analysis reveals that load has the greatest influence on wear rate, followed by distance and velocity.
ADVANCES IN MATERIALS AND PROCESSING TECHNOLOGIES
(2022)
Article
Engineering, Mechanical
Mohd Azmal Hussain, Aasiya Parveen, Nathi Ram Chauhan, Mohd Suhaib, Mohammad Waseem
Summary: This study investigates the wear behavior of aluminium hybrid composites developed through powder metallurgy. The effects of reinforcement content, compaction pressure, and applied load on wear results were analyzed. The study utilized Analysis of variance (ANOVA) and artificial neural network (ANN) for wear loss prediction, finding that load is the most influential parameter followed by reinforcement and compaction pressure.
SURFACE TOPOGRAPHY-METROLOGY AND PROPERTIES
(2022)
Proceedings Paper
Engineering, Mechanical
Payal Sharma, Nathi Ram Chauhan, Manish Saraswat
RECENT TRENDS IN THERMAL ENGINEERING, ICCEMME 2021
(2022)
Article
Engineering, Multidisciplinary
Aasiya Parveen, Nathi Ram Chauhan, Mohammad Waseem, Mohd Suhaib
Summary: This study developed a composite material Al/3 wt% Si3N4/4.5 wt% ZrO2 using powder metallurgy process and designed a connecting rod for TVS Apache 150 motor engine specifications using Solidworks software. The finite element method analysis in ANSYS Workbench showed a significant reduction in von-Mises stress for the developed composite material compared to existing composite materials.
ENGINEERING RESEARCH EXPRESS
(2021)
Proceedings Paper
Materials Science, Multidisciplinary
Saxena Neha Deepak, Chauhan Nathi Ram
Summary: This study investigates the effect of nanoparticles on traditional lubricant SAE 20 W40 and Virgin Coconut Oil (VCO), exploring the physio-chemical properties of both oils with TiO2 nanoadditives. The research aims to develop new nanolubricants with enhanced properties, offering potential benefits for machinery performance and durability.
MATERIALS TODAY-PROCEEDINGS
(2021)
Proceedings Paper
Materials Science, Multidisciplinary
Priyanka Singh, Nathi Ram Chauhan, S. Rajesha
Summary: This paper discusses the design and fabrication of a mini ball miller for grinding materials into nano form in a short period of time, and experiments were conducted to study the effect of milling speed and time on the microstructural bonding of Alumina/SiC composite.
MATERIALS TODAY-PROCEEDINGS
(2021)
Proceedings Paper
Materials Science, Multidisciplinary
Sakshi Singh, Nathi Ram Chauhan
Summary: In this study, the weight of an aircraft frame structure is optimized using a variable density method. A probabilistic Mg-based composite aircraft frame model is designed and iterated in Ansys software based on its topological properties, resulting in a significantly reduced density and weight percentage. The optimized structure demonstrates a decrease in both density and weight compared to domestic aircraft frames.
MATERIALS TODAY-PROCEEDINGS
(2021)
Proceedings Paper
Engineering, Industrial
Nathi Ram
RECENT ADVANCES IN MECHANICAL INFRASTRUCTURE ( ICRAM 2019)
(2020)
Article
Engineering, Electrical & Electronic
Samta Shastri, Yusuf Parvez, Nathi R. Chauhan
INTERNATIONAL JOURNAL OF POWER AND ENERGY SYSTEMS
(2020)
Article
Engineering, Multidisciplinary
Manish Saraswat, Nathi Ram Chauhan
ENGINEERING SCIENCE AND TECHNOLOGY-AN INTERNATIONAL JOURNAL-JESTECH
(2020)
Article
Engineering, Mechanical
Rosaria Del Toro, Maria Laura De Bellis, Marcello Vasta, Andrea Bacigalupo
Summary: This article presents a multifield asymptotic homogenization scheme for analyzing Bloch wave propagation in non-standard thermoelastic periodic materials. The proposed method derives microscale field equations, solves recursive differential problems within the unit cell, establishes a down-scaling relation, and obtains average field equations. The effectiveness of this approach is validated by comparing dispersion curves with those from the Floquet-Bloch theory.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2024)
Article
Engineering, Mechanical
Yue Bao, Zhengcheng Yao, Yue Zhang, Xueman Hu, Xiandong Liu, Yingchun Shan, Tian He
Summary: This paper proposes a novel triple-gradient phononic acoustic black hole (ABH) beam that strategically manipulates multiple gradients to enhance its performance. The study reveals that the ABH effect is not solely brought about by the thickness gradient, but also extends to the power-law gradients in density and modulus. The synergistic development of three different gradient effects leads to more pronounced and broader bandgaps in PCs.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2024)
Article
Engineering, Mechanical
Matthias Ryser, Jason Steffen, Bekim Berisha, Markus Bambach
Summary: This study investigates the feasibility of replacing complex experiments with multiple simpler ones to determine the anisotropic yielding behavior of sheet metal. The results show that parameter identifiability and accuracy can be achieved by combining multiple specimen geometries and orientations, enhancing the understanding of the yield behavior.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2024)
Article
Engineering, Mechanical
Wenjun Li, Pengfei Zhang, Siyong Yang, Shenling Cai, Kai Feng
Summary: This study presents a novel two-dimensional non-contact platform based on Near-field Acoustic Levitation (NFAL), which can realize both one-dimensional and two-dimensional transportation. Numerical and experimental results prove the feasibility and ease of this method.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2024)
Article
Engineering, Mechanical
Shuo Liu, Lu Che, Guodong Fang, Jun Liang
Summary: This study presents a novel lamina conjugated bond-based peridynamic (BB-PD) model that overcomes the limitations of material properties and is applicable to composite laminates with different stacking sequences. The accuracy and applicability of the model are validated through simulations of elastic deformation and progressive damage behavior, providing an explanation of the damage modes and failure mechanisms of laminated composite materials subjected to uniaxial loading.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2024)
Article
Engineering, Mechanical
Omar El-Khatib, S. Kumar, Wesley J. Cantwell, Andreas Schiffer
Summary: Sandwich-structured honeycombs (SSHCs) are hierarchical structures with enhanced mass-specific properties. A model capable of predicting the elastic properties of hexagonal SSHCs is presented, showing superior in-plane elastic and shear moduli compared to traditional honeycombs, while the out-of-plane shear moduli are reduced.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2024)
Article
Engineering, Mechanical
Zhi-Jian Li, Hong-Liang Dai, Yuan Yao, Jing-Ling Liu
Summary: This paper proposes a process-performance prediction model for estimating the yield strength and ultimate tensile strength of metallic parts fabricated by powder bed fusion additive manufacturing. The effect of main process variables on the mechanical performance of printed metallic parts is analyzed and the results can serve as a guideline for improvement. The accuracy of the proposed model is validated by comparison with literature.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2024)
Article
Engineering, Mechanical
Saman A. Bapir, Kawa M. A. Manmi, Rostam K. Saeed, Abdolrahman Dadvand
Summary: This study numerically investigates the behavior of an ultrasonically driven gas bubble between two parallel rigid circular walls with a cylindrical micro-indentation in one wall. The primary objective is to determine the conditions that facilitate the removal of particulate contamination from the indentation using the bubble jet. The study found that the bubble jet can effectively remove contamination from the indentation for certain ranges of indentation diameter, but becomes less effective for larger indentation diameters.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2024)
Article
Engineering, Mechanical
E. Polyzos, E. Vereroudakis, S. Malefaki, D. Vlassopoulos, D. Van Hemelrijck, L. Pyl
Summary: This research investigates the elastic and damage characteristics of individual composite beads used in 3D printed composites. A new analytical probabilistic progressive damage model (PPDM) is introduced to capture the elastic and damage attributes of these beads. Experimental results show strong agreement with the model in terms of elastic behavior and ultimate strength and strain.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2024)
