Journal of Mechanical Engineering Research and Developments最新文献_第2页

Arc stability characterization of double coated electrodes for hardfacing 堆焊用双涂层电极的电弧稳定性表征

Journal of Mechanical Engineering Research and Developments Pub Date : 2021-04-07 DOI: 10.30564/JMER.V4I1.2890

Odonel González-Cabrera, Carlos-René Gómez-Pérez, Héctor Arturo Kairús-Hernández-Díaz, Félix A. Díaz-Rosell

引用次数: 0

Analysis of turbulence on cylinder with additional fairing with free surface 带有自由面附加整流罩的气缸湍流分析

Journal of Mechanical Engineering Research and Developments Pub Date : 2021-04-07 DOI: 10.30564/JMER.V4I1.2643

S. Chen, Xiaomin Li

{"title":"Analysis of turbulence on cylinder with additional fairing with free surface","authors":"S. Chen, Xiaomin Li","doi":"10.30564/JMER.V4I1.2643","DOIUrl":"https://doi.org/10.30564/JMER.V4I1.2643","url":null,"abstract":"Article history Received: 1 December 2020 Accepted: 27 January 2021 Published Online: 9 April 2021 In this study, two dimensional unsteady flows of cylinder and cylinder with additional fairing close to a free surface were numerically investigated. The governing momentum equations were solved by using the Semi Implicit Method for Pressure Linked Equations(SIMPLE). The Volume of Fluid(VOF) method applied to simulate a free surface. Nonuniform grid structures were used in the simulation with denser grids near the cylinder. Under the conditions of Reynolds number 150624, 271123, 210874 and 331373, the cylinders were simulated with different depths of invasion. It was shown that the flow characteristics were influenced by submergence depth and Reynolds numbers. When the cylinder close to the free surface, the drag coefficient, lift coefficient and Strouhal numbers will increase due to the effect of free liquid surface on vortex shedding. With additional fairing, can effectively reduce the influence of the free surface on the drag coefficient. Fairing will reduce lift coefficient at high Reynolds numbers, but increase lift coefficient when Reynolds numbers are small. Fairing can effectively reduce Strouhal numbers, thus can well suppress the vortex induced vibration.","PeriodicalId":16153,"journal":{"name":"Journal of Mechanical Engineering Research and Developments","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88740023","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Precision Engineering Design Process for Optimal Design based on Engineering Sciences 基于工程科学的精密工程设计过程优化设计

Journal of Mechanical Engineering Research and Developments Pub Date : 2021-04-07 DOI: 10.30564/JMER.V4I1.2889

A. Javidinejad

引用次数: 0

Physics of deactivation of gyroscopic inertial forces 陀螺仪惯性力失活的物理学

Journal of Mechanical Engineering Research and Developments Pub Date : 2021-03-31 DOI: 10.5897/JMER2020.0530

R. Usubamatov, M. Bergander

{"title":"Physics of deactivation of gyroscopic inertial forces","authors":"R. Usubamatov, M. Bergander","doi":"10.5897/JMER2020.0530","DOIUrl":"https://doi.org/10.5897/JMER2020.0530","url":null,"abstract":"This new study on effects of gyroscope demonstrates the action on the spinning disc that the eight interrelated inertial torques system generated by its rotating masses. The physics behind this inertial torques manifest the action of the resistance and precession torques, which physics are described and explained. The latest research on the gyroscopic properties revealed the deactivation of the inertial torques that contradicts the principles of classical mechanics. Practical tests of the blocking of the gyroscope motion around one axis displays the deactivation of inertial torques acting around the axis of the load torque. In this condition, the gyroscope with one side support turns down under the action of its weight and frictional forces produced by the action of the precession torque and weight of the movable components. The precession torque is presented by the change in the angular momentum, while other inertial torques is deactivated. These phenomena present the new unknown gyroscopic effect that needs a deep study and explanation. This work considers the attempt to describe the physics of the deactivation of the gyroscopic inertial torques around two axes and the action of the precession torque in a case of the gyroscope motion around one axis. \u0000 \u0000 Key words: Gyroscope theory, inertial torque, deactivation of inertial torques","PeriodicalId":16153,"journal":{"name":"Journal of Mechanical Engineering Research and Developments","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80968967","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Transient thermal analysis of different types of IC engine cylinder fins by varying thickness and introducing slots 不同型号内燃机气缸翅片厚度变化及引入狭缝的瞬态热分析

Journal of Mechanical Engineering Research and Developments Pub Date : 2021-01-31 DOI: 10.5897/JMER2020.0536

A. Das, G. Harish, D. Purrab, J. Sachin, G. Suraj

{"title":"Transient thermal analysis of different types of IC engine cylinder fins by varying thickness and introducing slots","authors":"A. Das, G. Harish, D. Purrab, J. Sachin, G. Suraj","doi":"10.5897/JMER2020.0536","DOIUrl":"https://doi.org/10.5897/JMER2020.0536","url":null,"abstract":"Fins are extended surfaces used between two fluids for heat transfer between the hotter and colder fluid or between a solid and a fluid. There are various types of fins, viz. angular fins, circular fins, and rectangular fins. Engine piston chamber is the most precarious part of any automobile imperiled to extreme thermal shocks, hence prone to thermal stresses. Therefore, fins are introduced to cool the cylinder, which helps to improve engine performance considerably. In this study, rectangular and circular types of fins were selected, and its effect on temperature distribution and heat flux has been studied for with and without the introduction of slots. Firstly, different fins were modelled by using AUTODESK FUSION 360, then meshing and post-processing were done using ANSYS WORKBENCH. The results (plots of temperature and heat flux distribution) obtained for various case studies have been analyzed and compared which showcased that the slotted circular fin geometry having higher fin thickness (3 mm in this case) is the preferred fin geometry compared to other types of fin. \u0000 \u0000 Key words: Fins, Autodesk fusion 360, Ansys workbench 2020 academic Software, temperature distribution, and heat flux.","PeriodicalId":16153,"journal":{"name":"Journal of Mechanical Engineering Research and Developments","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81194181","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Thermal deformation of a thermal shield material vs. method of heat supply 热屏蔽材料的热变形与供热方式

Journal of Mechanical Engineering Research and Developments Pub Date : 2021-01-31 DOI: 10.5897/JMER2020.0531

L. I. Gracheva

{"title":"Thermal deformation of a thermal shield material vs. method of heat supply","authors":"L. I. Gracheva","doi":"10.5897/JMER2020.0531","DOIUrl":"https://doi.org/10.5897/JMER2020.0531","url":null,"abstract":"This work aims to analyze the thermal deformation of a thermal shield laminated material under a uniform or one-sided heating of up to 600°C/min. The material is made of a fiberglass composite polymer material based on phenol-phormaldehyde matrix. This work describes the method used to study the kinetics of thermal deformation of the composite material at different heating rates and a high-temperature of gas flow (2500°C). The state of the stressed-deformed samples made of a reinforced plastic is computed and used to measure the expanded temperature of the materials under one-sided heating. It is shown that under both force and thermal loading, the linear dependence of the coefficient of thermal deformation Т on temperature, stresses in the sample developed to prevent the bending of free samples. For a bent sample, there is no stress gradient ( = 0) under increased heating rate of the loaded samples, leading to an increase in the stress gradient values. The data are compared with dilatometry results obtained at a uniform temperature field and heating rates of 20 to 1100°C. \u0000 \u0000 Key words: Thermal shield, spacecraft, re-entry, composite material, high temperature, fiberglass, dilatometer.","PeriodicalId":16153,"journal":{"name":"Journal of Mechanical Engineering Research and Developments","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86089404","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Peristaltic transport of a second-grade dusty fluid in a tube 二级含尘流体在管内的蠕动输送

Journal of Mechanical Engineering Research and Developments Pub Date : 2020-10-31 DOI: 10.5897/JMER2019.0518

H. Tariq, A. A. Khan

引用次数: 4

In the road of assessing the validity of logarithmic law in wake flows: A review 在尾流对数规律有效性评价的道路上——综述

Journal of Mechanical Engineering Research and Developments Pub Date : 2020-10-31 DOI: 10.5897/jmer2019.0521

Sabzpoushan Seyedali

{"title":"In the road of assessing the validity of logarithmic law in wake flows: A review","authors":"Sabzpoushan Seyedali","doi":"10.5897/jmer2019.0521","DOIUrl":"https://doi.org/10.5897/jmer2019.0521","url":null,"abstract":"In any application of wall-bounded or shear fluid flows, near-wall boundary layer and shear layer are the places of struggle between viscous and inertial forces. After development and spread of using wall functions for modeling near-wall region of boundary layer in wall-bounded turbulent flows, the importance of accurate prediction and modeling of different layers of boundary layer, particularly the so-called logarithmic layer becomes more crucial in aerodynamics. Due to the intrinsic characteristics of flow structure in log-layer and wide-spread applications of wake flows, the presence of these characteristics in wake flows rather than wall-bounded flows opens a new window to the researchers to investigate the possibility of using log-law within wake regions, particularly on wake centerline for modeling purposes. On the applications of wake modeling and studying, we can point out to wing and blade trailing edge design, exhaust flow of pipes and ducts (e.g. nozzle exhaust or internal flow of polymers in dimpled pipes), and vortex generator design which are just a few examples of the areas with great interest in both fundamental scientific research, that is, developing optimum and accurate Computational Fluid Dynamics (CFD) tools and their industrial applications. In this article, a brief description about different approaches, previous efforts and case studies, and similar analogous problems is presented to give a better perception to the future researchers. \u0000 \u0000 Key words: Logarithmic law, turbulent boundary layer, wake centerline, vortical structure.","PeriodicalId":16153,"journal":{"name":"Journal of Mechanical Engineering Research and Developments","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91301230","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The Dynamic Simulation of Rotary Inertia on Light vehicle-Slope I 轻型车辆旋转惯量的动力学模拟-斜坡[j]

Journal of Mechanical Engineering Research and Developments Pub Date : 2020-06-24 DOI: 10.30564/jmer.v3i2.1800

Run Xu, Boyong Hur

引用次数: 0

The Simulation on Dynamic of Rotary Inertia and Engine’s Inflamer in Light Vehicle 轻型汽车旋转惯量与发动机消炎器动力学仿真

Journal of Mechanical Engineering Research and Developments Pub Date : 2020-06-24 DOI: 10.30564/jmer.v3i2.1774

Run Xu

引用次数: 1