Numerical Analysis of Inner Flow Field for Disk MRF Brake

2011 ◽  
Vol 181-182 ◽  
pp. 251-256
Author(s):  
Cheng Ye Liu ◽  
Feng Yan Yi ◽  
Ke Jun Jiang
Keyword(s):  
Numerical Analysis ◽  
Flow Field ◽  
Velocity Distribution ◽  
Theoretical Data ◽  
Numerical Data ◽  
Axial Direction ◽  
Analysis Data ◽  
Brake Torque ◽  
Set Up ◽  
Volume Method

According to structure of disk MRF brake computational model of inner flow field for MRF was set up at simplified condition when MRF was regarded as Bingham model. Velocity distribution in inner flow field had been analyzed at different brake velocities and magnetic intensity using finite volume method (FVM), and brake torque and power had also been received at the same condition by integral method. Numerical analysis data were compared with theoretical data. Result showed that velocity distribution of inner flow field was not linear at axial direction, and that brake torque of disk MRF brake was constant approximately, and that numerical data and theoretic data were identical and it can provide reference for design.

Numerical Analysis of the Turbulent Flow Field Applied to Thermal Spallation Drilling

2004 ◽  
Author(s):  
Angela O. Nieckele ◽  
Luis Fernando Figueira da Silva ◽  
Joa˜o Carlos R. Pla´cido
Keyword(s):  
Reynolds Number ◽  
Numerical Analysis ◽  
Flow Field ◽  
Gas Phase ◽  
Accurate Determination ◽  
Rock Surface ◽  
Drilling Technique ◽  
High Reynolds ◽  
Drilling Conditions ◽  
Volume Method

Thermal spallation is a possible drilling technique which consists of using hot supersonic jets as heat source to perforate hard rocks at high rates. This work presents a numerical analysis of a typical spallation drilling configuration, by the finite volume method. The time-averaged conservation equations of mass, momentum and energy are solved to determine the turbulent compressible gas phase flow field. Turbulence is predicted by the classical high Reynolds number κ-ε model, as well as with a low Reynolds number κ-ε model. The influence of the jet Reynolds number is investigated. Special attention is given to the rock surface temperature, since its accurate determination is required to predict spallation rates under field-drilling conditions.

Numerical analysis of the influence of early fuel injection on charge motion in a direct injection spark ignition engine using scale-resolving simulations

2019 ◽  
Vol 21 (4) ◽  
pp. 664-682
Author(s):  
Martin Theile ◽  
Martin Reißig ◽  
Egon Hassel ◽  
Dominique Thévenin ◽  
Martin Hofer ◽  
...  
Keyword(s):  
Numerical Analysis ◽  
Flow Field ◽  
Fuel Injection ◽  
Direct Injection ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Post Processing ◽  
Charge Motion ◽  
Set Up ◽  
Direct Injection Spark Ignition

This work summarizes the numerical analysis of the effect of early fuel injection on the charge motion in a direct injection spark ignition engine concerning cyclic fluctuations of the flow field. The combination of the scale-resolving turbulence model “Scale Adaptive Simulation” and post-processing routines for vortex trajectory visualization allows for a detailed insight into the temporal resolved and cycle-dependent behavior of the charge motion. In the first part, a simplified engine set-up is presented and used as a validation case to ensure correct behavior of the turbulence model and post-processing routines. In the second part, the computational fluid dynamics model of the real engine is introduced. The application of the proposed vortex tracking algorithm is shown, and a short discussion about the transient behavior of the charge motion in this engine set-up is given. The third part describes the analysis of the influence of the fuel injection on the charge motion at different engine speeds from 1000 to 3000 r/min and variations of the intake pressure from 1 to 2 bar. Finally, the impact on different flow field properties at possible ignition timings is discussed. Changes in mean flow field quantities as well as in aerodynamic fluctuations are found as a consequence of fuel injection.

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.

The Numerical Analysis of the Velocity and Pressure Distribution of the Oil Film in Heavy Hydrostatic Thrust Bearing

2014 ◽  
Vol 541-542 ◽  
pp. 658-662
Author(s):  
Jian Li ◽  
Yuan Chen ◽  
Yang Chun Yu ◽  
Zhu Xin Tian ◽  
Yu Huang
Keyword(s):  
Mathematical Model ◽  
Numerical Analysis ◽  
Pressure Distribution ◽  
Working Conditions ◽  
Thrust Bearing ◽  
Rotation Speed ◽  
The Other ◽  
Surface Load ◽  
Oil Film ◽  
Volume Method

To study the velocity and pressure distribution of the oil film in a heavy hydrostatic thrust bearing, a mathematical model of the velocity is proposed and the finite volume method (FVM) has been used to simulate the flow field under different working conditions. Some pressure experiments were carried out and the results verified the correctness of the simulation. It is concluded that the pressure distribution varies small under different rotation speed when the surface load on the workbench is constant. But the velocity of the oil film is influenced greatly by the rotation speed. When the rotation speed of the workbench is as quick as enough, the velocity of the oil film on one radial side of the pad will be zero, that is to say the lubrication oil will be drained from the other three sides of the recess.

Nanoparticle Precipitation in a T-Mixer: Coupling Experimental and Numerical Investigations of the Fluid Dynamics With the Solid Formation Processes

2006 ◽  
Author(s):  
Johannes Gradl ◽  
Florian Schwertfirm ◽  
Hans-Christoph Schwarzer ◽  
Hans-Joachim Schmid ◽  
Michael Manhart ◽  
...  
Keyword(s):  
Flow Field ◽  
Fluid Dynamic ◽  
Concentration Field ◽  
Population Balance ◽  
Mixing Process ◽  
Image Velocimetry ◽  
Modeling Material ◽  
Field Information ◽  
Set Up ◽  
3D Information

Mixing and consequently fluid dynamic is a key parameter to tailor the particle size distribution (PSD) in nanoparticle precipitation. Due to fast and intensive mixing a static T-mixer configuration is capable for synthesizing continuously nanoparticles. The flow and concentration field of the applied mixer is investigated experimentally at different flow rates by Particle Image Velocimetry (PIV) and Laser Induced Fluorescence (LIF). Due to the PIV measurements the flow field in the mixer was characterized qualitatively and the mixing process itself is quantified by the subsequent LIF-measurements. A special feature of the LIF set up is to detect structures in the flow field, which are smaller than the Batchelor length. Thereby a detailed insight into the mixing process in a static T-Mixer is given. In this study a CFD-based approach using Direct Numerical Simulation (DNS) in combination with the solid formation kinetics solving population balance equations (PBE) is applied, using barium sulfate as modeling material. A Lagrangian Particle Tracking strategy is used to couple the flow field information with a micro mixing model and with the classical theory of nucleation. We found that the DNS-PBE approach including macro and micro mixing, combined with the population balance is capable of predicting the full PSD in nanoparticle precipitation for different operating parameters. Additionally to the resulting PSD, this approach delivers a 3D-information about all running subprocesses in the mixer, i.e. supersaturation built-up or nucleation, which is visualized for different process variables.

Historic city, tourism performance and development: The balance of social behaviours in the city of Santiago de Compostela (Spain)

2016 ◽  
Vol 16 (3) ◽  
pp. 282-293 ◽  
Author(s):  
Belén Mª Castro Fernández ◽  
Rubén Camilo Lois González ◽  
Lucrezia Lopez
Keyword(s):  
Numerical Data ◽  
City Centre ◽  
City Development ◽  
Santiago De Compostela ◽  
Final Destination ◽  
City Tourism ◽  
Set Up ◽  
Historic City ◽  
The City ◽  
The Way

Santiago de Compostela is an iconic place. From the 9th century through to the present day the city has acted as the final destination of a major pilgrimage route named after it. In the article we ask ourselves how the contemporary reinvention of the pilgrimage and pilgrimages on the Way of St. James has boosted tourism development in the city. Development has been concentrated in the historic city centre and in the area around the cathedral. The importance of tourism has transformed the significance of the city itself, which acquires a magical component as a place of arrival and encounter for all kinds of visitors. The historic city has been set up in the 20th century as a destination for the Way and for cultural tourism. The buildings, particularly those connected with the pilgrimage route, become highly attractive and symbolic places and tourists carry out a number of rituals in them. They travel and enjoy Santiago as a unique experience. The study of tourism and of the tourist transformation of Santiago de Compostela is undertaken using a qualitative and quantitative method. The article analyses the heritage and symbolic value of the historic centre, together with the growth of its tourism activities. Numerical data are also provided on the perceptions and behaviour of visitors using surveys carried out by the city's Tourism Observatory.

Numerical analysis of the acoustic and flow field associated with perforated liners with variable acoustic forcing

2013 ◽  
Author(s):  
Cosimo Bianchini ◽  
Antonio Andreini ◽  
Bruno Facchini ◽  
Ignazio Vitale ◽  
Fabio Turrini
Keyword(s):  
Numerical Analysis ◽  
Flow Field ◽  
Acoustic Forcing

Een slechte start en dan?

2017 ◽  
Vol 33 (3) ◽  
Author(s):  
Henk-Jan Dirven ◽  
Wouter van der Torre ◽  
Seth van den Bossche
Keyword(s):  
Analysis Data ◽  
Working Environment ◽  
Work Situation ◽  
Financial Situation ◽  
Work Related ◽  
Self Employment ◽  
Level Of Satisfaction ◽  
Set Up ◽  
Employment Quality

A bad start and what then? The work situation of self-employed entrepreneurs with negative and positive start motives This article assesses the extent to which the quality of labor varies between solo self-employed who set up a business for negative reasons and those who started for positive reasons. A negative reason is, for example, not being able to find a suitable job as an employee; an example of a positive reason is wanting to be self-employed from the very beginning. Quality of labor is measured according to the person's financial situation, security of employment, quality of the working environment and work satisfaction. In the analysis, data are used from the Self-employment Survey conducted by Statistics Netherlands and TNO. Compared to self-employed persons with a positive motivation, those who were negatively motivated show lower performance in terms of their business's financial situation, income position, work-related mental fatigue (burn-out), self-perceived health status, concern about the business's future and the level of satisfaction. However, in absolute terms, the vast majority appear to be satisfied with their work situation, enthusiastic and not intending to quit self-employment.

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