Numerical and experimental research on engagement process of wet multi-plate friction clutches with groove consideration

2019 ◽  
Vol 233 (10) ◽  
pp. 1464-1482 ◽  
Author(s):  
Peng-hui Wu ◽  
Jin Xu ◽  
Xiao-Jun Zhou
Keyword(s):  
Heat Transfer ◽  
Finite Element ◽  
Numerical Model ◽  
Influencing Factors ◽  
Experimental Research ◽  
Revolution Speed ◽  
Heat Transfer Theory ◽  
Wet Clutch ◽  
Engagement Process ◽  
And Behavior

A numerical model is established to investigate the effects of the influencing factors such as design parameters and operating conditions on the performance and behavior of the engagement process of the wet clutch based on the Navier–Stokes equations, contact mechanics, and heat transfer theory. A finite element contact model called KE contact model is used to analyze the rough contact during engagement process and thermal effect on the viscosity is considered based on heat transfer theory. The integration of the grooving into the simulation and the method of coupled finite element by domain decomposition of groove and ungrooved areas are put forward to facilitate the analysis. The experimental results agree well with the numerical model which takes the normal pressure, the temperature of ATF, relative revolution speed, the permeability and the groove geometry into account. The results of numerical simulation and the experiment indicate that the applied pressure not only affects the engagement time, but also has influence on the value of the engagement torque. Besides, the engagement time is roughly proportional to the relative revolution speed. The influencing factors such as the temperature of ATF, the permeability, grooves, the torque judders and effects of PID control parameters are also discussed in the paper. The performance and behavior of the engagement of the wet clutch were studied by two methods of numerical calculation and experimental research, which make the working process of the wet clutch more detailed.

Optimization of Bulk Hgcdte Growth in a Directional Solidification Furnace by Numerical Simulation

1995 ◽  
Vol 398 ◽  
Author(s):  
A.V. Bune ◽  
D.C. Gillies ◽  
S.L. Lehoczky
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Finite Element ◽  
Crystal Growth ◽  
Numerical Model ◽  
Directional Solidification ◽  
Growth Conditions ◽  
Finite Element Code ◽  
Interface Shape ◽  
Solidification Furnace

ABSTRACTA numerical model of heat transfer by combined conduction, radiation and convection was developed using the FIDAP finite element code for NASA's Advanced Automated Directional Solidification Furnace (AADSF). The prediction of the temperature gradient in an ampoule with HgCdTe is a necessity for the evaluation of whether or not the temperature set points for furnace heaters and the details of cartridge design ensure optimal crystal growth conditions for this material and size of crystal. A prediction of crystal/melt interface shape and the flow patterns in HgCdTe are available using a separate complementary model.

Multiphysics for Early Stage Cement Hydration: Theoretical Framework

2011 ◽  
Vol 255-260 ◽  
pp. 4247-4250
Author(s):  
Zhen Liu ◽  
Bin Zhang ◽  
Xiong Bill Yu
Keyword(s):  
Heat Transfer ◽  
Energy Transfer ◽  
Theoretical Model ◽  
Numerical Model ◽  
Cement Hydration ◽  
Early Stage ◽  
Diffusion Theory ◽  
Equation System ◽  
Heat Transfer Theory ◽  
Reaction Theory

The chemical hydration involves complex multiphysical processes including mass and energy transfer, chemical reactions and consequently stress development and shrinkage. This paper proposed a multiphysics numerical model to predict the kinetics cement paste. The chemical reaction theory, heat transfer theory, diffusion theory, and continuum mechanics were coupled in the theoretical model. A comprehensive theoretical model is established with partial different equation system, auxiliary functions, and typical boundary conditions.

Solidification Heat Transfer and Base Separation Analysis in the Casting of an Energetic Material in a Projectile

2005 ◽  
Author(s):  
Dawei Sun ◽  
S. Ravi Annapragada ◽  
Suresh V. Garimella ◽  
Sanjeev Sing
Keyword(s):  
Heat Transfer ◽  
Finite Element ◽  
Numerical Model ◽  
Residual Stresses ◽  
Energetic Materials ◽  
Energetic Material ◽  
Complex Geometries ◽  
Experimental Measurements ◽  
Linear Temperature ◽  
High Prandtl Number

This paper investigates the problem of base separation in the casting of energetic materials in a projectile. Special challenges that arise in casting high Prandtl number energetic materials in projectiles of complex geometries are addressed. A comprehensive numerical model is developed by integrating finite volume and finite element methods to analyze the thermal and flow fields as well as the residual stresses. The predictions, which are confirmed by experimental measurements, suggest that sustenance of a linear temperature profile along the projectile axis can eliminate base separation, and also reduce residual stresses in the final casting.

scholarly journals Implementing air-based thermally activated building systems in retrofitted tertiary buildings – Towards the proof of concept

2021 ◽  
Vol 2042 (1) ◽  
pp. 012075
Author(s):  
M Cézard ◽  
M Labat ◽  
S Lorente
Keyword(s):  
Heat Transfer ◽  
Finite Element Method ◽  
Finite Element ◽  
Numerical Model ◽  
Design Method ◽  
Proof Of Concept ◽  
General Design ◽  
Thermally Activated ◽  
Building Systems ◽  
Energy Balances

Abstract Here we document the design method of an air-based thermally activated building system (TABS) suited for the retrofitting of tertiary buildings, for cooling purposes mainly. The first phase of this work provides a general design and checks its consistency with the specifications of tertiary buildings by means of basic energy balances. Second, a numerical model of both the TABS and the room is developed under a finite element method multi-physics environment to better estimate the transient heat transfer for the proposed retrofitting solution. This results in the specifications for building at 1:1 scale prototype whose construction is documented.

Numerical Simulation on the Temperature Field of Steel 1045 Quenched by Different Hardening Media

2013 ◽  
Vol 444-445 ◽  
pp. 1222-1228
Author(s):  
Jian Bin Xie ◽  
Chang Chang Wu ◽  
Jing Fan ◽  
Miao Fu ◽  
Deng Feng Hu
Keyword(s):  
Heat Transfer ◽  
Finite Element ◽  
Temperature Field ◽  
Temperature Fields ◽  
Cooling Curves ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Heat Transfer Theory ◽  
Quenching Process ◽  
Estimate Method

Based on the experimental measured cooling curves and the boiling heat transfer theory, the inverse problem of nonlinear heat conduct equation for Steel 1045 quenched by different hardening media was established by functional analysis and finite element method, and the surface heat-transfer coefficients in continuous cooling during quenching were calculated by nonlinear estimate method. Then the constitutive model of Steel 1045 during quenching was established subsequently. Finally, the temperature field of Steel 1045 cylinder quenched by different hardening media was simulated by Finite Element Methods (FEM). Results show that the calculated temperature fields agree with the practical quenching process.

Analyses of Flow Field and Heat Exchange about Limestone Grain in the Preheater

2014 ◽  
Vol 915-916 ◽  
pp. 974-977
Author(s):  
Yong Gang Liu ◽  
Xiao Yang Zhang ◽  
Jing Yang Zheng ◽  
Jin Fa Xie
Keyword(s):  
Heat Transfer ◽  
Finite Element ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Convection Heat Transfer ◽  
Particle Model ◽  
Convection Heat ◽  
Convection Heat Transfer Coefficient ◽  
Hot Air ◽  
Heat Transfer Theory

According to the structural features of the vertical preheater, the 2-dimention finite element models are set up for the section of the preheater with different arrangement and diameters for the limestone grains. The situation of gas-solid two-phase flow between the limestone grains and the hot air in the preheater is simulated by the discrete particle model. Based on the heat transfer theory, the convection heat transfer coefficient between the limestone grains and the hot air is deduced by means of the experimental correlation of the air cross-flow tube bundles. On the simulation of the 2-dimention finite element model of the vertical preheater based on the FLOTRAN module of ANSYS, the temperature field, pressure field and velocity field of the limestone grains are obtained. The results show that there is a little change of convection heat transfer coefficient by varying the arrangement of limestone grains. The convection heat transfer coefficient is improved by employing the limestone grains with little diameter. The larger the gap between the grains is, the larger the convection heat transfer coefficient is.

Numerical Simulation for Thick-Walled Hollow Axle during Cross Wedge Rolling

2011 ◽  
Vol 337 ◽  
pp. 270-273 ◽  
Author(s):  
Yang Jiang ◽  
Bao Yu Wang ◽  
Zheng Huan Hu ◽  
Jian Guo Lin
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Finite Element ◽  
Numerical Model ◽  
Rolling Process ◽  
Cross Wedge Rolling ◽  
Finite Element Software ◽  
Temperature Distributions ◽  
Simulation Results ◽  
Deform 3D

The paper investigates a process of cross wedged rolling (CWR) for manufacturing thick-walled hollow axles. A finite element numerical model coupled deformation and heat transfer of CWR is established using commercial finite element software DEFORM-3D. The rolling process of hollow axle during CWR is simulated successfully. The stress, strain and temperature distributions of workpiece are obtained and analyzed. The simulation results show that forming thick-walled hollow axles through CWR is feasible.

3D Numerical Simulation of Heat Transfer for the Vertical U Type Berried Pipe of the Ground Source Heat Pump

2013 ◽  
Vol 827 ◽  
pp. 203-208
Author(s):  
Yang Zhang ◽  
Yong Feng Qi
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Finite Element ◽  
Heat Pump ◽  
Element Model ◽  
Ground Source Heat Pump ◽  
Pump System ◽  
Heat Pump System ◽  
Ground Source ◽  
Heat Transfer Theory

Based on transient heat transfer theory and finite element method, a 3D finite element model was created to simulate the heat transfer of the vertical U type berried pipe of the ground source heat pump system. At the same time, the pipe algorithm applied successfully in the numerical simulation of concrete temperature field was introduced. The corresponding program was written. Taking the true experiment conditions as the input data and boundary condition of the computation model, the 3D dynamic simulation of the heat transfer between the berried pipe and sandy soil was carried out. The calculated temperatures of the output water of the pipe and the measure points in soil at different times met the experiment results very well, which verified the effectiveness and the reliability of the algorithm and the model. Beneficial exploration is made for providing more detailed and accurate data for the designer.

scholarly journals Dynamic Temperature Rise Mechanism and Some Controlling Factors of Wet Clutch Engagement

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Zhang Zhigang ◽  
Shi Xiaohui ◽  
Guo Dong
Keyword(s):  
Heat Transfer ◽  
Temperature Rise ◽  
Transmission Model ◽  
Radial Temperature ◽  
Dynamic Temperature ◽  
Heat Transfer Theory ◽  
Clutch Engagement ◽  
Friction Disk ◽  
Wet Clutch ◽  
Three Components

The friction transmission model of wet clutch is established to analyze the friction transmission mechanism of its engagement. The model is developed by applying both the average flow model and the elastic contact model between the friction disk and separator plate. The key components during wet clutch engagement are the separator plate, friction disk, and lubricant. The one-dimension transient models of heat transfer in radial direction for the three components are built on the basis of the heat transfer theory and the conservation law of energy. The friction transmission model and transient heat transfer models are coupled and solved by using the Runge-Kutta numerical method, and the radial temperature distribution and their detailed parametric study for the three components are conducted separately. The simulation results show that the radial temperature for the three components rises with the increase of radius in engagement. The changes in engagement pressure, lubricant viscosity, friction lining permeability, combined surface roughness RMS, equivalent elasticity modulus, difference between dynamic and static friction coefficients, and lubricant flow have important influence on the temperature rise characteristics. The proposed models can get better understanding of the dynamic temperature rise characteristics of wet clutch engagement.

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