Mixed EHL numerical analysis and leakage experiment of skeleton reciprocating oil seal

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Hua-Lin Yang ◽  
Xiulong Li ◽  
Weiwei Sun ◽  
Fang Deng ◽  
Jie Du
Keyword(s):  
Contact Pressure ◽  
Design Methodology ◽  
Elastohydrodynamic Lubrication ◽  
Deformation Analysis ◽  
Fluid Viscosity ◽  
Asperity Contact ◽  
Direct Proportion ◽  
Element Analysis ◽  
Content Type ◽  
Simulation Process

Purpose This paper aims to present the mixed elastohydrodynamic lubrication (EHL) model and obtain the leakage characteristics for the skeleton reciprocating oil seal. Design/methodology/approach The model consists of a finite element analysis of the contact pressure, a fluid mechanics analysis of the fluid film, a contact analysis of the asperity contact pressure, a deformation analysis of the seal lip and an iterative numerical simulation process. Findings Simulation results show that the leakage is in direct proportion to the seal roughness and speed, and in inverse proportion to the fluid viscosity. Comparisons with the experimental results verify the validity of the mixed EHL model. Originality/value This study provides a helpful method to calculate the leakage of the skeleton reciprocating oil seal, which shortens its development cycles.

A numerical method to investigate the mixed lubrication performances of journal-thrust coupled bearings

2019 ◽  
Vol 71 (9) ◽  
pp. 1099-1107
Author(s):  
Guo Xiang Guo Xiang ◽  
Yanfeng Han ◽  
Renxiang Chen ◽  
Jiaxu Wang Jiaxu Wang ◽  
Ni Xiaokang
Keyword(s):  
Thrust Bearing ◽  
Load Capacity ◽  
Elastohydrodynamic Lubrication ◽  
Hydrodynamic Pressure ◽  
Mixed Lubrication ◽  
Hydrodynamic Effect ◽  
Asperity Contact ◽  
Content Type ◽  
Lubrication Regime ◽  
Coupled Effect

Purpose This paper aims to present a numerical model to investigate the mixed lubrication performances of journal-thrust coupled bearings (or coupled bearings). Design/methodology/approach The coupled hydrodynamic effect (or coupled effect) between the journal and the thrust bearing is considered by ensuring the continuity of the hydrodynamic pressure and the flow field at the common boundary. The mixed lubrication performances of the coupled bearing are comparatively studied for the cases of considering and not considering coupled effect. Findings The simulated results show that the hydrodynamic pressure distributions for both the journal and thrust bearing are modified due to the coupled effect. The decreased load capacity of the journal bearing and the increased load capacity of the thrust bearing can be observed when the coupled effect is considered. And the coupled effect can facilitate in reducing the asperity contact load for both the journal and thrust bearing. Additionally, the interaction between the mixed lubrication behaviors, especially for the friction coefficient, of the journal and the thrust bearing is significant in the elastohydrodynamic lubrication regime, while it becomes weak in the mixed lubrication regime. Originality/value The developed model can reveal the mutual effects of the mixed lubrication behavior between the journal and the thrust bearing.

Multigrid method for the solution of EHL point contact with bio-based oil as lubricants for smooth and rough asperity

2018 ◽  
Vol 70 (4) ◽  
pp. 599-611 ◽  
Author(s):  
Vishwanath B. Awati ◽  
Shankar Naik ◽  
Mahesh Kumar N.
Keyword(s):  
Design Methodology ◽  
Reynolds Equation ◽  
Multigrid Method ◽  
Approximation Scheme ◽  
Point Contact ◽  
Elastohydrodynamic Lubrication ◽  
Alternative Source ◽  
Content Type ◽  
Longitudinal Roughness ◽  
Isothermal Case

Purpose The purpose of this paper is to study the elastohydrodynamic lubrication point contact problem with bio-based oil as lubricants for an isothermal case. The simulation of the problem is analyzed on smooth and rough asperity. Design/methodology/approach The modified Reynolds equation is discretized using finite difference and multigrid method with full approximation scheme (FAS), applied for its solution with varying load and speed. Findings This paper traces out the comparison of minimum and central film thickness with the standard formulation of Hamrock and Dowson. The effect of longitudinal roughness on surfaces is investigated by means of numerical simulations. Originality/value The results obtained are comparable with the standard results, and are shown by graphs and tables. Bio-based products bring out an alternative source of lubricant to reduce energy crises.

Numerical modelling of coupled seepage-deformation subjected to rainfall infiltration in unsaturated slope

2020 ◽  
Vol 17 (6) ◽  
pp. 867-875
Author(s):  
Edgar Jr Joe ◽  
Nazri Ali ◽  
Siti Norafida Jusoh
Keyword(s):  
Numerical Modelling ◽  
Design Methodology ◽  
Factor Of Safety ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Field Monitoring ◽  
Rainfall Infiltration ◽  
Deformation Analysis ◽  
Content Type ◽  
Fully Coupled

Purpose This study aims to propose another alternative numerical modelling tool, i.e. ABAQUS, to simulate a fully coupled seepage-deformation analysis in unsaturated slope subjected to rainfall infiltration. Design/methodology/approach The effect of rainfall infiltration on the response of pore water pressure and factor of safety has been analysed and discussed. The results of this study have also been validated based on the results of field monitoring and previous numerical modelling. Findings The results from ABAQUS show a better agreement with those from field monitoring compared to other numerical modelling tools. Originality/value The procedures adopted in this study can be adopted and used as a guide to model similar slope problems in ABAQUS.

Construction by Contour Crafting using sulfur concrete with planetary applications

2016 ◽  
Vol 22 (5) ◽  
pp. 848-856 ◽  
Author(s):  
Behrokh Khoshnevis ◽  
Xiao Yuan ◽  
Behnam Zahiri ◽  
Jing Zhang ◽  
Bin Xia
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Simulation Model ◽  
Design Methodology ◽  
Construction Material ◽  
Construction Process ◽  
Element Analysis ◽  
Content Type ◽  
Contour Crafting ◽  
Finite Element Analysis Simulation

Purpose This paper aims to report on the experiments with the Contour Crafting Automated Construction process using sulfur concrete as the choice of construction material. Design/methodology/approach Several experiments have been performed at centimeter and meter scales. A finite element analysis simulation model for the behavior of sulfur concrete-based structures has been developed. Experimental results were compared with the results of simulation. Findings Sulfur concrete has numerous terrestrial applications and is potentially an ideal construction material for planetary construction. Originality/value Experimental samples of sulfur concrete were fabricated using a novel mixer/extrusion system. The mechanism was proven to be durable and stable after more than 500 h of work.

Designs of low frictional coefficients for joint bearings by inlaying graphites and liquid spraying of MoS2

2018 ◽  
Vol 70 (9) ◽  
pp. 1630-1635 ◽  
Author(s):  
Jun Cao ◽  
Zhongwei Yin
Keyword(s):  
High Temperature ◽  
Design Methodology ◽  
Element Analysis ◽  
Content Type ◽  
Nuclear Plants ◽  
Temperature Environment ◽  
Frictional Coefficients ◽  
Practical Implications ◽  
Permissible Stresses ◽  
High Temperature Environment

PurposeThe purpose of this paper is to solve the problem of joint bearings that cannot work in high temperature because of their high frictional coefficients.Design/methodology/approachTwo methods of inlaying graphites and liquid spraying of MoS2are designed. The arrangement of graphites is shown and its frictional coefficients (COFs) are discussed. MoS2coating is deposited by liquid spraying. The ingredients of liquid spraying of MoS2are illustrated. Stresses, structure deformations and fatigue life are analyzed by finite element analysis.FindingsResults show that both two designed methods can decrease COFs effectively. All stresses are in the limit of the maximum permissible stresses. The new designed bearings can be safety worked in sealed and high temperature environment which are proved by fatigue analyses.Practical implicationsTwo new designs can help joint bearings work in nuclear plants because of their low COFs and litter wear. The new designs can improve bearings life.Originality/valueTwo methods of decreasing COFs of joint bearings are designed in this paper. The technologies are illustrated. The proper scopes of applications of two designed methods are discussed.

Numerical investigation of tubular structures generated by cutting method and pattern scale factor (PSF) method

2019 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Xin Ren ◽  
Fang Cheng Liu ◽  
Xiang Yu Zhang ◽  
Yi Min Xie
Keyword(s):  
Scale Factor ◽  
Tubular Structure ◽  
Deformation Analysis ◽  
Tubular Structures ◽  
Element Analysis ◽  
Cutting Method ◽  
Content Type ◽  
Adjustment Method ◽  
Cut Method ◽  
Pattern Scale

Purpose This paper aims to study the tensile performance, deformation characteristics, auxeticity and stability of different auxetic tubular structures generated by cutting method and pattern scale factor (PSF) method using validated finite element analysis. Design/methodology/approach Two types of auxetic tubular structures were designed by a coordinate transformation method and the PSF adjustment method, respectively. ABAQUS/explicit solver was used for the large deformation analysis and the displacement of key nodes was extracted to calculate Poisson’s ratio value and evaluate the deformation of tubular structures. Findings The random cut method was not suitable for designing auxetic tubular structures. Vertical and horizontal cut approach was suitable, but the change of the tubular diameter was lower than the tubular structures generated by the PSF adjustment method. Research limitations/implications Simple ways to generate auxetic tubular structure, which can be made into intelligent and foldable equipment, such as annuloplasty rings, angioplasty stents and oesophageal stents. By combined with shape memory polymer, various smart tubular materials and structures with various functions can be designed, especially in medical scaffold and other medical equipment fields. Originality/value The auxetic characteristic of tubular structure designed by using random cut method has been investigated for the first time. The outcome of this study would be very useful design tubular structures with better mechanical properties.

Simplified analysis of iron loss in three-phase transformer considering rotating loss

2013 ◽  
Vol 33 (1/2) ◽  
pp. 74-84
Author(s):  
Yang Liu ◽  
Yanli Zhang ◽  
Dexin Xie ◽  
Baodong Bai
Keyword(s):  
Design Methodology ◽  
Silicon Steel ◽  
Iron Loss ◽  
Magnetic Flux Density ◽  
Element Analysis ◽  
Content Type ◽  
Three Phase ◽  
The Finite Element Analysis ◽  
Simplified Method ◽  
Property Measurement

Purpose – A simplified method for calculating iron loss of three-phase transformer is proposed in this paper. The rotating iron loss measured from 2-D vector magnetic property measurement system of gain-oriented silicon steel sheet can be taken into account in this method. The paper aims to discuss these issues. Design/methodology/approach – The finite element analysis formulation is combined with the magnetic reluctivity model expressed by diagonal tensor for 2-D nonlinear and anisotropic magnetic problem, while the iron loss is computed in terms of the interpolation of rotational loss curves measured under various loci of controlled magnetic flux density B. Findings – The iron loss of three-phase transformer is obtained by the proposed method. And the calculating iron loss is verified with experimental results. Originality/value – The method presented in this paper enables the iron loss of three-phase transformer to be more accurately calculated and more easily applied, considering the rotational iron loss.

Design and fast verification of pocket elliptical journal bearings

2014 ◽  
Vol 66 (3) ◽  
pp. 393-401 ◽  
Author(s):  
Fabrizio Stefani
Keyword(s):  
Design Methodology ◽  
Journal Bearings ◽  
Fast Method ◽  
Analysis Method ◽  
Element Analysis ◽  
Content Type ◽  
Finite Element Analysis Method ◽  
Bearing Design ◽  
And Performance ◽  
Industrial Level

Purpose – The purpose of this paper was to conceive a fast method to verify design and performance of elliptical pocket journal bearings. Design/methodology/approach – The computer-aided verification of pocket journal bearings is performed by means of a suitable finite element analysis method. Findings – The results of sample analyses indicate that the machining tolerances are very influential on elliptical pocket bearing performances, and they must be included among the input data. Originality/value – Although elliptical pocket bearings are widely used in turbomachineries, the influence of their design on performance has not been specifically investigated. A lot of works about tribological models are available, but few of them focus on their application to bearing design at the industrial level.

A digital design methodology for surgical planning and fabrication of customized mandible implants

2017 ◽  
Vol 23 (1) ◽  
pp. 101-109 ◽  
Author(s):  
Emad Abouel Nasr ◽  
Abdurahman Mushabab Al-Ahmari ◽  
Khaja Moiduddin ◽  
Mohammed Al Kindi ◽  
Ali K. Kamrani
Keyword(s):  
Ct Scan ◽  
Design Methodology ◽  
Fused Deposition Modeling ◽  
Bone Structure ◽  
Biomechanical Study ◽  
Digital Design ◽  
Implant Design ◽  
Element Analysis ◽  
Content Type ◽  
Fused Deposition

Purpose The purpose of this paper is to demonstrate the route to digitize the customized mandible implants consisting of image acquisition, processing, implant design, fitting rehearsal and fabrication using fused deposition modeling and electron beam melting methodologies. Design/methodology/approach Recent advances in the field of rapid prototyping, reverse engineering, medical imaging and image processing have led to new heights in the medical applications of additive manufacturing (AM). AM has gained a lot of attention and interest during recent years because of its high potential in medical fields. Findings Produced mandible implants using casting, milling and machining are of standard sizes and shapes. As each person’s physique and anatomical bone structure are unique, these commercially produced standard implants are manually bent before surgery using trial and error methodology to custom fit the patient’s jaw. Any mismatch between the actual bone and the implant results in implant failure and psychological stress and pain to the patient. Originality/value The novelty in this paper is the construction of the customized mandibular implant from the computed tomography (CT) scan which includes surface reconstruction, implant design with validation and simulation of the mechanical behavior of the design implant using finite element analysis (FEA). There has been few research studies on the design and customization of the implants before surgery, but there had been hardly any study related to customized design implant and evaluating the biomechanical response on the newly designed implant using FEA. Though few studies are related to FEA on the reconstruction plates, but their paper lacks the implant design model and the reconstruction model. In this research study, an integrated framework is developed for the implant design, right from the CT scan of the patient including the softwares involved through out in the study and then performing the biomechanical study on the customized design implant to prove that the designed implant can withstand the biting and loading conditions. The proposed research methodology which includes the interactions between medical practitioners and the implant design engineers can be incorporated to any other reconstruction bone surgeries.

Deformation analysis and reinforcement of jin-gang tower in jacking method

2016 ◽  
Vol 13 (2) ◽  
pp. 163-168 ◽  
Author(s):  
Xiaonan Zhang ◽  
Sanyuan Shi ◽  
Hongyu Zhao ◽  
Man Lu ◽  
Xuguang Li
Keyword(s):  
Cultural Heritage ◽  
Design Methodology ◽  
Yunnan Province ◽  
Deformation Analysis ◽  
Stress Release ◽  
Content Type ◽  
Positive Effect ◽  
Protection Of Cultural Heritage

Purpose This paper aims to first analyze the reasons of a brick-wooden building tilts in Yunnan province in China. Then, a jacking method which combines the stress release methods and the excavation of stress release trench were put forward. Design/methodology/approach This method uses the anchor static pile to guarantee the safety of the building in the process of rectifying. Findings The practice showed that the inclination rate of the building was stable in the process of jacking, which proved the efficiency of the proposed method. Originality/value It has a great value for similar rectification projects, and for the protection of cultural heritage and ancient buildings have a positive effect.

Sign in / Sign up

Export Citation Format

Share Document