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.

scholarly journals Effects of operating and material parameters on the thermal characteristics of a wet clutch

2021 ◽  
Vol 13 (7) ◽  
pp. 168781402110341
Author(s):  
Zhigang Zhang ◽  
Ling Zou ◽  
Hang Liu ◽  
Yonglong Chen ◽  
Benzhu Zhang
Keyword(s):  
Heat Flux ◽  
Applied Pressure ◽  
Thermal Characteristics ◽  
Thermal Models ◽  
Material Parameters ◽  
Heat Transfer Theory ◽  
Friction Disk ◽  
Viscous Shear ◽  
Wet Clutch ◽  
Transient Thermal

Based on the frictional mechanism of a wet clutch, frictional models of wet clutch engagement were established using the modified Reynolds equation and the elastic contact model between frictional pairs. Then, the heat flux models for the viscous shear and asperity friction were built, and the two-dimensional transient thermal models for the separator plate, friction disk, and ATF heat convection model were deduced based on the heat transfer theory and conservation law of energy. Finally, the Runge–Kutta numerical method was used to solve the frictional and thermal models. The average temperature of the separator plate, friction disk, and ATF were calculated. The effects of operating and material parameters, such as applied pressure, initial angular velocity, friction lining permeability, surface combined roughness RMS, equivalent elastic modulus, and ATF flow, on the thermal characteristics of friction pairs and ATF during engagement, were studied. The simulation results show that the temperature characteristics of the separator plate, friction disk, and ATF depend mainly on the viscous shear and asperity friction heat flux, and that the operating and material parameters of the wet clutch also have significant impacts on the overall variation trend of the thermal characteristics of the separator plate, friction disk, and ATF.

Optimizing the Smoothness and Temperatures of a Wet Clutch Engagement Through Control of the Normal Force and Drive Torque

1999 ◽  
Vol 122 (1) ◽  
pp. 119-123 ◽  
Author(s):  
Mikael Holgerson
Keyword(s):  
Temperature Rise ◽  
Normal Force ◽  
Dynamic Performance ◽  
Automatic Transmission ◽  
Test Rig ◽  
Friction Characteristics ◽  
Drive Torque ◽  
Clutch Engagement ◽  
Wet Clutch ◽  
Transmission Gear

Automatic transmission gear shifts are handled by wet clutches, which determine the smoothness. The clutch face temperatures during the engagements are often an important parameter for the total clutch life. A wet clutch test rig has been used to evaluate how a wet clutch engagement can be improved in terms of smoothness and temperature. This was performed with control based upon knowledge about friction characteristics and dynamic performance. The parameters used for control were the drive torque and the normal force on the clutch. By drive torque shut-off and reduced normal force the torque variations were greatly reduced and the temperature rise was decreased by 37%. [S0742-4787(00)01601-5]

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.

Temperature Rise Times in Pneumatic Tires

1976 ◽  
Vol 4 (3) ◽  
pp. 181-189 ◽  
Author(s):  
S. K. Clark
Keyword(s):  
Heat Transfer ◽  
Thermal Properties ◽  
Temperature Rise ◽  
Thermal Equilibrium ◽  
Transfer Coefficients ◽  
Pneumatic Tire ◽  
Heat Transfer Coefficients ◽  
Idealized Model ◽  
Pneumatic Tires

Abstract An idealized model is proposed for heating of a pneumatic tire. A solution is obtained for the temperature rise of such a model. Using known thermal properties of rubber and known heat transfer coefficients, the time to reach thermal equilibrium is estimated.

Modeling of Heat Transfer and Fluid Hydrodynamics for a Multidisc Wet Clutch

1995 ◽  
Author(s):  
Yubo Yang ◽  
Robert C. Lam ◽  
Yih Fang Chen ◽  
Hiroshi Yabe
Keyword(s):  
Heat Transfer ◽  
Wet Clutch ◽  
Fluid Hydrodynamics

Modeling and experimental research on engaging characteristics of wet clutch

2019 ◽  
Vol 71 (1) ◽  
pp. 94-101 ◽  
Author(s):  
Yanzhong Wang ◽  
Yuan Li ◽  
Yang Liu ◽  
Wei Zhang
Keyword(s):  
Contact Surface ◽  
Hydrodynamic Lubrication ◽  
Load Capacity ◽  
Lubricating Oil ◽  
Centrifugal Effect ◽  
Element Analysis ◽  
Content Type ◽  
Clutch Engagement ◽  
Wet Clutch ◽  
Engagement Process

PurposeTo gain in-depth understandings of engaging characteristics, the purpose of this paper is to improve the model of wet clutches to predict the transmitted torque during the engagement process.Design/methodology/approachThe model of wet clutch during the engagement process took main factors into account, such as the centrifugal effect of lubricant, permeability of friction material, slippage factor of lubricant on contact surface and roughness of contact surface. Reynolds’ equation was derived to describe the hydrodynamic lubrication characteristics of lubricant film between the friction plate and the separated plate, and an elastic-plastic model of the rough surfaces contact based on the finite element analysis was used to indicate the loading force and friction torque of the contact surface.FindingsThe dynamic characteristics of wet clutch engagement time, relative speed, hydrodynamic lubrication of lubricating oil, rough surface contact load capacity and transfer torque can be obtained by the wet clutch engagement model. And the influence of the groove shape and depth on the engaging characteristics is also analyzed.Originality/valueThe mathematical model of the wet clutch during the engagement process can be used to predict the engaging characteristics of the wet clutch which could be useful to the design of the wet clutch.

Analysis of Temperature Field Based on Hollow Sucker Rod Hot Flushing Technology

2014 ◽  
Vol 1073-1076 ◽  
pp. 2257-2262
Author(s):  
Jie Yu Du ◽  
Jiang Xie ◽  
Yu Qi Zhao ◽  
Li Peng Zhang ◽  
Rui Bin Zhu
Keyword(s):  
Heat Transfer ◽  
Temperature Field ◽  
Low Pressure ◽  
Calculation Model ◽  
Simulation System ◽  
Well Production ◽  
Transfer Theory ◽  
Heat Transfer Theory ◽  
Sucker Rod ◽  
Theory Calculation

The hot flushing is a major means of removing wax. For low pressure reservoir, it is possible to produce a large number of washing fluid flowing into the formation, which affects the well production recovery. The application of hollow sucker rod hot flushing technology can avoid fluid pouring back into the formation, and the wells can keep production. Based on the principle of hollow sucker rod hot flushing and heat transfer theory, calculation model of temperature field was established, and hollow sucker rod hot flushing simulation system was developed, which can guide flushing in oilfield.

scholarly journals Heat transfer on simplified pre-period stage of tunnel fire

2019 ◽  
Vol 23 (Suppl. 3) ◽  
pp. 799-808
Author(s):  
Hungwei Liu ◽  
Wei Yao
Keyword(s):  
Heat Transfer ◽  
Temperature Distribution ◽  
Heating Rate ◽  
Theoretical Solution ◽  
Theoretical Equation ◽  
Thermal Engineering ◽  
Transient Temperature ◽  
Tunnel Fire ◽  
Transient Temperature Distribution ◽  
Heat Transfer Theory

Tunnel fire is a part of applied thermal problems. With increase of transient temperature of the tunnel fire on the structure surface (i.e. tunnel lining), the heat transfer from the surface is possibly varying transient temperature distribution within the structure. The transient temperature distribution is also possibly damaging the composition of structure (micro-crack) because of critical damage temperature. Therefore, the transient temperature distribution has a significantly important role on defining mechanical and physical properties of structure and determining thermal-induced damaged region. The damage at pre-period stage of tunnel fire is perhaps more significant than that at the other period stages because of thermal gradient. Consequently, a theoretical model was developed for simplifying complicated thermal engineering during pre-period stage of tunnel fire. A hollow solid model (HSM) in a combination of dimensional analysis and heat transfer theory with Bessel?s Function and Duhamel?s Theorem were employed to verify a theoretical equation for dimensionless transient temperature distribution (DTTD) under linear transient thermal loading (LTTL). Experimental and numerical methods were also adopted to approve the results from this theoretical equation. The heating rate (M) is a primary variable for discussing DTTD on three means. The heating rate of 10.191, 10 and 240?C/min were applied to experimental and numerical studies. The experimental and numerical results are consistent with the theoretical solution, successfully verifying that the theoretical solution can predict the DTTD well in field. This equation can be used for thermal/tunnel engineers to evaluate the damaged region and to obtain the parameters related to DTTD.

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