Three-Dimensional Thermohydrodynamic Analysis of a Wet Clutch With Consideration of Grooved Friction Surfaces

A model is developed to investigate the effect of radial grooves and waffle-shape grooves on the performance of a wet clutch. Three-dimensional formulation of the governing equations, boundary conditions, and numerical solution scheme are presented for modeling the thermal aspects of the engagement process in a wet clutch. The thermal model includes full consideration of the viscous heat dissipation in the fluid as well as heat transfer into the separator, the friction material, and the core disk. The convective terms in the energy equations for the oil as well as the heat conduction equations in the bounding solids are properly formulated to determine the temperature fields corresponding to the domains between grooves. Roughness, centrifugal force, deformability, and permeability of the friction material with grooves are taken into account. The effects of groove geometry such as groove depth, grooved area, and number of grooves on the engagement characteristic of a wet clutch are investigated. It is also shown that the thermal effects in a wet clutch influence the engagement time and the torque response and should be included in the analytical studies.

Download Full-text

Thermal Characteristics of a Wet Clutch

Journal of Tribology ◽

10.1115/1.2834111 ◽

1999 ◽

Vol 121 (3) ◽

pp. 610-617 ◽

Cited By ~ 66

Author(s):

J. Y. Jang ◽

M. M. Khonsari

Keyword(s):

Thermal Effects ◽

Heat Dissipation ◽

Thermal Characteristics ◽

Friction Material ◽

Solution Technique ◽

Governing Equations ◽

Viscous Heat ◽

Wet Clutch ◽

Engagement Process ◽

Full Consideration

A comprehensive formulation of the governing equations, boundary conditions, and numerical solution technique is presented for modeling the thermal aspects of the engagement process in a wet clutch. The thermal model includes full consideration of the viscous heat dissipation in the fluid as well as heat transfer into the separator, friction material, and the core disk. Roughness, waviness, deformability and permeability of the friction material are taken into account. It is shown that very large temperatures develop in the fluid during the engagement process which takes place on the time scale of one second. It is also shown that thermal effects influence the engagement time and the torque behavior of a clutch and should be included in the analytical studies.

Download Full-text

A Numerical Study on the Influence of Grooves on Heat Transfer Performance of Wet Clutch

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.249-250.517 ◽

2012 ◽

Vol 249-250 ◽

pp. 517-522 ◽

Cited By ~ 2

Author(s):

Yu Long Lei ◽

Jie Tao Wen ◽

Xing Zhong Li ◽

Cheng Yang

Keyword(s):

Heat Transfer ◽

Numerical Study ◽

Three Dimensional ◽

Friction Material ◽

Navier Stokes ◽

Navier Stokes Equation ◽

Linear Distribution ◽

Exchange Performance ◽

Wet Clutch ◽

Oil Flow

In order to evaluate the efficacy of grooves on cooling performance of wet clutch, a numerical analysis based on the computational fluid dynamics (CFD) code FLUENT is presented in this study. This analysis is based on the numerical solution of the three-dimensional Navier-Stokes equation, coupled with the energy equation in the flow and the heat conduction equations in the friction material and the core disk. The turbulence characteristics were predicted using RNGk-ε model. The flow field and temperature distributions in radial grooves are obtained. It is shown that radial grooves possess the highest heat exchange performance at the entrance and is not linear distribution in the radial direction and cooling oil flow has a little effect on the highest temperature of friction plate. With the developed analysis method, it is possible to easily and quickly investigate the heat transfer behaviour of wet cluth with groove patterns.

Download Full-text

Dendritic growth of an elliptical paraboloid with forced convection in the melt

Journal of Fluid Mechanics ◽

10.1017/s0022112089002946 ◽

1989 ◽

Vol 208 ◽

pp. 575-593 ◽

Cited By ~ 30

Author(s):

Ramagopal Ananth ◽

William N. Gill

Keyword(s):

Reynolds Number ◽

Dendritic Growth ◽

Moving Boundary ◽

Solid Phase ◽

Three Dimensional ◽

Temperature Fields ◽

Navier Stokes ◽

Energy Equations ◽

Theory And Experiments ◽

Elliptical Paraboloid

All experimental observations of the growth of fully developed dendritic ice crystals indicate that the shape of the tip region is an elliptical paraboloid. Therefore, moving-boundary solutions of the three-dimensional Navier-Stokes and energy equations are obtained here for the shape-preserving growth of isothermal elliptical paraboloids by using the Oseen approximation which is valid for the low-Reynolds-number viscous flows which prevail in dendritic growth. Explicit expressions for the flow and the temperature fields are derived in a simple way using Ivantsov's method. It is shown that the growth Péclet number, PG, is a function of the aspect ratio A, the Stefan number St, the Reynolds number Re, and the Prandtl number Pr. As the Reynolds number increases PG becomes linear in St, less dependent on A and ultimately varies roughly as Re½.A comparison between the exact solutions given here and the experiments of Kallungal (1974) indicate that A decreases as Re increases. This result agrees qualitatively with the experiments of Kallungal (1974) and Chang (1985). The differences between theory and experiments for Re > 10−3 may be due to attachment kinetic resistance to growth along the c-axis and capillary effects at the tip which make ice dendrites non-isothermal and create conduction in the solid phase. However, more accurate simultaneous measurements of R1 and R2 are needed to determine definitively the mechanisms responsible for these deviations between theory and experiment.

Download Full-text

Simulation and experimental study on the influence of oil groove structure on the drag torque of the wet clutch

Industrial Lubrication and Tribology ◽

10.1108/ilt-12-2019-0507 ◽

2021 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Chengjun Wang ◽

Wujian Ding ◽

Xudong Zheng ◽

Haiqiang Zhu ◽

Zuzhi Tian ◽

...

Keyword(s):

Heat Dissipation ◽

Simulation Analysis ◽

Three Dimensional ◽

Reference Object ◽

Drag Torque ◽

Content Type ◽

Oil Film ◽

Wet Clutch ◽

Groove Structure ◽

Dimensional Simulation

Purpose This paper aims to design a single and double throat oil groove structure, which can reduce the drag torque of the wet clutch. Design/methodology/approach A three-dimensional simulation model was established herein using the computational fluid dynamics method. The influence of oil groove structure on the oil film flow field and the drag torque is obtained by a simulation. Findings Compared with the traditional radial oil groove, the results show that the single throat oil groove structure reduces the drag torque by about 24.59%; the double throat oil groove reduces the drag torque by about 47.27%. As the speed difference increases, the average temperature rise of the oil film of the double throat oil groove is 4°C lower than that of the single throat oil groove, indicating that it has good heat dissipation performance. The analysis results were verified by experimental results. Originality/value In this paper, the radial oil groove is taken as the reference object, and the structure of the oil groove is designed and improved. The simulation analysis and experiment verify the rule of the influence of the oil groove structure on the drag torque, which provides a new design idea for reducing the drag torque of wet clutch.

Download Full-text

TLBM MODEL FOR THE VISCOUS HEAT DISSIPATION IN INCOMPRESSIBLE LIMIT

International Journal of Modern Physics B ◽

10.1142/s0217979207035959 ◽

2007 ◽

Vol 21 (01) ◽

pp. 117-126 ◽

Cited By ~ 2

Author(s):

LIN ZHENG ◽

BAO CHANG SHI ◽

ZHEN HUA CHAI

Keyword(s):

Evolution Equation ◽

Viscous Dissipation ◽

Heat Dissipation ◽

Present Model ◽

Distribution Functions ◽

Temperature Fields ◽

Equilibrium Density ◽

Special Method ◽

Dissipation Term ◽

Viscous Heat

The viscous dissipation term in energy equation is investigated with the lattice Boltzmann method, and the double distribution functions (DDF) are applied, respectively, to simulate the velocity and the temperature fields. Compared with other existing models, the complicated evolution equation is simplified and the energy equilibrium density function is completely independent of the density distribution function in present model [unlike the authors He et al. [J. Comput. Phys.146, 282 (1998)]], when dealing with viscous dissipation term problem. In this paper, the viscous dissipation term is directly treated as a source term and the complex space discretion in the evolution equation can also be avoided by special method in part 2. Efficiency and accuracy of present model is validated through numerical experiments on Couette and natural convection flows.

Download Full-text

Parametric analysis of wear factors of a wet clutch friction material with different groove patterns

Proceedings of the Institution of Mechanical Engineers Part J Journal of Engineering Tribology ◽

10.1177/1350650116689236 ◽

2017 ◽

Vol 231 (8) ◽

pp. 1056-1067 ◽

Cited By ~ 4

Author(s):

M Li ◽

MM Khonsari ◽

DMC McCarthy ◽

Joakim Lundin

Keyword(s):

Temperature Field ◽

Material Properties ◽

Parametric Analysis ◽

Wear Test ◽

Friction Material ◽

Asperity Contact ◽

Wet Clutch ◽

Engagement Process ◽

Insight Into ◽

Friction Lining

The experimentally observed, two-stage wear in the wet clutch friction material is directly related to temperature and engagement load. To gain insight into the durability of the friction lining, an extensive parametric analysis of the factors is performed that takes into account different groove patterns (waffle shape, radial, and spiral), internal structure and material properties. The temperature field is predicted using a thermohydrodynamic analysis with the consideration of the asperity contact stress during the engagement process. The results should be useful to facilitate the industrial design of friction lining by avoiding costly wear test.

Download Full-text