Simulation and experimental study on lubrication of high-speed reducer of electric vehicle

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Fuchun Jia ◽  
Yulong Lei ◽  
Xianghuan Liu ◽  
Yao Fu ◽  
Jianlong Hu
Keyword(s):  
Flow Field ◽  
Electric Vehicle ◽  
High Speed ◽  
Content Type ◽  
Speed Reducer ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Novel Method ◽  
Set Up ◽  
Volume Method

Purpose The lubrication of the high-speed reducer of an electric vehicle is investigated. The specific contents include visualization of the flow field inside reducer, lubrication evaluation of bearings and efficiency experiment. Design/methodology/approach The flow field inside reducer at five working conditions: straight, uphill, downhill, left lean and right lean is simulated by smoothed particle hydrodynamics (SPH). According to the instantaneous number of particles through bearings, the lubrication states of bearings are evaluated. The test platform is set up to measure the efficiency of the reducer. Findings The flow field inside the reducer is obtained, the lubrication of bearings needs to be improved, the efficiency of the electric vehicle reducer meets the requirement. Originality/value The SPH method is used to simulate lubrication instead of using the traditional grid-based finite volume method. A novel method to evaluate the lubrication of bearings is proposed. The method and conclusions can guide electric vehicle reducer design.

Incompressible smoothed particle hydrodynamics for MHD double-diffusive natural convection of a nanofluid in a cavity containing an oscillating pipe

2019 ◽  
Vol 30 (2) ◽  
pp. 882-917 ◽  
Author(s):  
Abdelraheem M. Aly
Keyword(s):  
Natural Convection ◽  
Smoothed Particle Hydrodynamics ◽  
Cavity Wall ◽  
Lagrangian Description ◽  
Content Type ◽  
Wide Range ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Incompressible Smoothed Particle Hydrodynamics ◽  
Double Diffusive

Purpose This paper aims to adopt incompressible smoothed particle hydrodynamics (ISPH) method to simulate MHD double-diffusive natural convection in a cavity containing an oscillating pipe and filled with nanofluid. Design/methodology/approach The Lagrangian description of the governing partial differential equations are solved numerically using improved ISPH method. The inner oscillating pipe is divided into two different pipes as an open and a closed pipe. The sidewalls of the cavity are cooled with a lower concentration C_c and the horizontal walls are adiabatic. The inner pipe is heated with higher concentration C_h. The analysis has been conducted for the two different cases of inner oscillating pipes under the effects of wide range of governing parameters. Findings It is found that a suitable oscillating pipe makes a well convective transport inside a cavity. Presence of the oscillating pipe has effects on the heat and mass transfer and fluid intensity inside a cavity. Hartman parameter suppresses the velocity and weakens the maximum values of the stream function. An increase on Hartman, Lewis and solid volume fraction parameters leads to an increase on average Nusselt number on an oscillating pipe and left cavity wall. Average Sherwood number on an oscillating pipe and left cavity wall decreases as Hartman parameter increases. Originality/value The main objective of this work is to study the MHD double-diffusive natural convection of a nanofluid in a square cavity containing an oscillating pipe using improved ISPH method.

Numerical investigation of anguilliform locomotion by the SPH method

2019 ◽  
Vol 30 (1) ◽  
pp. 328-346 ◽  
Author(s):  
Amin Rahmat ◽  
Hossein Nasiri ◽  
Marjan Goodarzi ◽  
Ehsan Heidaryan
Keyword(s):  
Drag Coefficient ◽  
Numerical Investigation ◽  
Sph Method ◽  
Content Type ◽  
Aquatic Locomotion ◽  
Wide Range ◽  
Particle Hydrodynamics ◽  
Dummy Particles ◽  
Smoothed Particle ◽  
Sph Algorithm

Purpose This paper aims to introduce a numerical investigation of aquatic locomotion using the smoothed particle hydrodynamics (SPH) method. Design/methodology/approach To model this problem, a simple improved SPH algorithm is presented that can handle complex geometries using updatable dummy particles. The computational code is validated by solving the flow over a two-dimensional cylinder and comparing its drag coefficient for two different Reynolds numbers with those in the literature. Findings Additionally, the drag coefficient and vortices created behind the aquatic swimmer are quantitatively and qualitatively compared with available credential data. Afterward, the flow over an aquatic swimmer is simulated for a wide range of Reynolds and Strouhal numbers, as well as for the amplitude envelope. Moreover, comprehensive discussions on drag coefficient and vorticity patterns behind the aquatic are made. Originality/value It is found that by increasing both Reynolds and Strouhal numbers separately, the anguilliform motion approaches the self-propulsion condition; however, the vortices show different pattern with these increments.

scholarly journals Impact and Fire Modeling Considerations Employing SPH Coupling to a Dilute Spray Fire Code

2009 ◽  
Author(s):  
Alexander L. Brown
Keyword(s):  
High Speed ◽  
Good Method ◽  
Predictive Tool ◽  
Surface Deposition ◽  
Impact Surface ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Model Inadequacy ◽  
The Impact ◽  
Adequate Method

Transportation accidents and the subsequent fire present a concern. Particularly energetic accidents like an aircraft impact or a high speed highway accident can be quite violent. We would like to develop and maintain a capability at Sandia National Laboratories to model these very challenging events. We have identified Smoothed Particle Hydrodynamics (SPH) as a good method to employ for the impact dynamics of the fluid for severe impacts. SPH is capable of modeling viscous and inertial effects for these impacts for short times. We have also identified our fire code Lagrangian/Eulerian (L/E) particle capability as an adequate method for fuel transport and spray modeling. A fire code can also model the subsequent fire for a fuel impact. Surface deposition of the liquid may also be acceptably predicted with the same code. These two methods (SPH and L/E) typically employ complimentary length and timescales for the calculation, and are potentially suited for coupling given adequate attention to relevant details. Length and timescale interactions are important considerations when joining the two capabilities. Additionally, there are physical model inadequacy considerations that contribute to the accuracy of the methodology. These models and methods are presented and evaluated. Some of these concerns are detailed for a verification type scenario used to show the work in progress of this coupling capability. The importance of validation methods and their appropriate application to the genesis of this class of predictive tool are also discussed.

Experimental study on the effect of pressure and flow rate on cavitation in a poppet throttle valve

2019 ◽  
Vol 72 (5) ◽  
pp. 629-636
Author(s):  
Jian Zhang ◽  
Tingting Luo
Keyword(s):  
Flow Rate ◽  
Pressure Difference ◽  
High Speed ◽  
High Speed Camera ◽  
Experimental Conditions ◽  
Content Type ◽  
Experimental Support ◽  
Throttle Valve ◽  
Set Up

Purpose The purpose of this paper is to study the variation of cavitation scale with pressure and flow in poppet throttle valve, to obtain the cavitation scale under pressure and flow conditions and to provide experimental support for the research of suppressing throttle valve cavitation and cavitation theory. Design/methodology/approach A hydraulic cavitation platform was set up, a valve was manufactured with highly transparent PMMA material and a high-speed camera was used to observe the change in cavitation scale. Findings Through experiments, it is found that the pressure difference between inlet and outlet of throttle valve affects the cavitation scale, and the more the pressure difference is, the easier the cavitation will be formed. Under the condition of small pressure difference, the cavitation is not obvious and reducing the pressure difference can effectively suppress the cavitation; the flow rate also affects the cavitation scale, the smaller the flow rate, the more difficult the cavitation will be formed and the lower the flow rate, the more the cavitation will be suppressed. Research limitations/implications Because of the magnification factor of the high-speed camera lens, the morphology of smaller bubbles cannot be observed in this study, and the experimental conditions need to be improved in the follow-up study. Originality/value This study can provide experimental support for the study of throttle valve cavitation suppression methods and cavitation theory.

Natural convection from heated fin shapes in a nanofluid-filled porous cavity using incompressible smoothed particle hydrodynamics

2019 ◽  
Vol 29 (12) ◽  
pp. 4569-4597 ◽  
Author(s):  
Abdelraheem M. Aly ◽  
Zehba Raizah ◽  
Mitsuteru Asai
Keyword(s):  
Heat Transfer ◽  
Porous Medium ◽  
Natural Convection ◽  
Smoothed Particle Hydrodynamics ◽  
Fluid Flows ◽  
Content Type ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Incompressible Smoothed Particle Hydrodynamics ◽  
Darcy Parameter

Purpose This study aims to focus on the numerical simulation of natural convection from heated novel fin shapes in a cavity filled with nanofluid and saturated with a partial layer of porous medium using improved incompressible smoothed particle hydrodynamics (ISPH) method. Design/methodology/approach The dimensionless of Lagrangian description for the governing equations were numerically solved using improved ISPH method. The current ISPH method was improved in term of wall boundary treatment by using renormalization kernel function. The effects of different novel heated (Tree, T, H, V, and Z) fin shapes, Rayleigh number Ra(103 – 106 ), porous height Hp (0.2-0.6), Darcy parameter Da(10−5 − 10−1 ) and solid volume fraction ϕ(0.0-0.05) on the heat transfer of nanofluid have been investigated. Findings The results showed that the variation on the heated novel fin shapes gives a suitable choice for enhancement heat transfer inside multi-layer porous cavity. Among all fin shapes, the H-fin shape causes the maximum stream function and Z-fin shape causes the highest value of average Nusselt number. The concentrations of the fluid flows in the nanofluid region depend on the Rayleigh and Darcy parameters. In addition, the penetrations of the fluid flows through porous layers are affected by porous heights and Darcy parameter. Originality/value Natural convection from novel heated fins in a cavity filled with nanofluid and saturated with a partial layer of porous medium have been investigated numerically using improved ISPH method.

Numerical model of two-phase mechanical face seal with shallow grooves based on finite volume method

2020 ◽  
Vol 72 (10) ◽  
pp. 1303-1309
Author(s):  
Wenbin Gao ◽  
Weifeng Huang ◽  
Tao Wang ◽  
Ying Liu ◽  
Zhihao Wang ◽  
...  
Keyword(s):  
Flow Field ◽  
Phase Change ◽  
Finite Volume Method ◽  
Peer Review ◽  
Finite Volume ◽  
Fluid Model ◽  
Mechanical Seal ◽  
Two Phase ◽  
Content Type ◽  
Volume Method

Purpose By modeling and analyzing the two-phase mechanical seal of the fan-shaped groove end face, which is prone to phase change, an effective method to study the flow field of the mechanical seal when both cavitation and boiling exist simultaneously is found. Design/methodology/approach Based on the finite volume method, a fluid model was developed to investigate a two-phase mechanical seal. The validity of the proposed model was verified by comparing with some classical models. Findings By modeling and analyzing the two-phase mechanical seal of the fan-shaped groove end face, which is prone to phase change, the analysis of the gap flow field of the mechanical seal was realized when cavitation and boiling existed simultaneously. Originality/value Based on the model proposed for different conditions, the pressure and phase states in the shallow groove sealing gap were compared. The phase change rate between the mechanical seal faces was also investigated. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-12-2019-0537/

LES of Airflow Distribution for CRH2 Electric Motor Train Units

2014 ◽  
Vol 687-691 ◽  
pp. 109-112
Author(s):  
Zhong Zan Wang ◽  
Zhao Hui Qi ◽  
Hui Tian
Keyword(s):  
Electric Motor ◽  
High Speed ◽  
Wall Functions ◽  
Eddy Simulation ◽  
Airflow Distribution ◽  
Large Eddy ◽  
Model Coefficient ◽  
Set Up ◽  
Volume Method ◽  
Temperature And Velocity Fields

In the premise of parallel computing, large eddy simulation (LES) model was adopted to set up math formers for the characteristics of airflow origination in CRH2 Electric Motor Train Units(EMU) in this paper. The Smagorinsky-Lilly dynamic sub-grid model was adopted for fitting local turbulent structure and confirming benchmark model coefficient. Amended balance layer model was used to the wall functions. The temperature and velocity fields in the compartments were numerically simulated. Furthermore, area discretization adopted finite volume method. The results showed, adopting the method of enlarging calculation region, the instantaneous and continuity of turbulence were reflected truly and accurately. The analysis provided a reference for LES of airflow organization in high-speed train. It was also a new reference for the evaluation of comfort environment in the train.

The Prediction of High-Speed Landslide Movement and Simulation of Generated Impulsive Wave by SPH Method

2011 ◽  
Vol 378-379 ◽  
pp. 418-422
Author(s):  
Ji Lun Miao ◽  
Jing Qiu Chen ◽  
Cen Wen
Keyword(s):  
High Speed ◽  
Limit Equilibrium ◽  
Soil Mass ◽  
Equilibrium Analysis ◽  
Sph Method ◽  
Limit Equilibrium Analysis ◽  
Particle Hydrodynamics ◽  
Sample Test ◽  
Smoothed Particle ◽  
Landslide Movement

A sliding block model is developed for predicting the runout of high-speed landslides, which couple with SPH method (Smoothed Particle Hydrodynamics) to simulate impulse wave. This model adopts the limit equilibrium analysis approach to simulate the whole travel process of the soil mass from the onset of the landslide. The submarine landslide produces highly unsteady and rapidly varied flows, so it was very complicated by fixed grid numerical simulations. The SPH method is a meshfree particle-based Lagrangian method. A sample test is given which shows the impulsive waves generated by high-speed landslide can be reproduced well.

A Proposal of a Haptic System for Real-Time Interaction with Clay-Like Objects

2014 ◽  
Vol 1079-1080 ◽  
pp. 631-637
Author(s):  
Lan Hai Liu ◽  
Satoshi Miyake ◽  
Katsuhito Akahane ◽  
Makoto Sato
Keyword(s):  
Real Time ◽  
Particle System ◽  
High Viscosity ◽  
Fluid Simulation ◽  
Time Interaction ◽  
Time Simulation ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Novel Method ◽  
The Stability

People often interact with deformable objects when they are kneading clay or making traditional desserts, either directly with their hands and fingers or through tools. Haptic interactions with virtual clay-like objects would significantly make the simulations more interesting and more real. However, to achieve a stable and real-time simulation of a clay-like particle system with high viscosity is challenging. In this research, we propose a novel method that allows real-time haptic interaction with clay-like objects. The particle system is based on a SPH(Smoothed-Particle Hydrodynamics) model, and the procedure of the conventional SPH method for fluid simulation is improved for simulating a particle system especially of high viscosity. The haptic rendering is done by a string-based haptic interface SPIDAR-G. We evaluate the performance and the stability of the proposed method in the end.

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