SAE TECHNICAL PAPER SERIES Modeling of Heat Transfer and Fluid Hydrodynamics for a Multidisc Wet Clutch Yubo Yang, Robert C. Lam and Yih Fang Chen Borg-Warner Automotive Hiroshi Yabe NSK-Warner MAR 0 7 1995 The Engineering Society Advancing Mobility n~and Sea Air and S~ace. International Congress and Exposition Detroit, Michigan February 27 - March 2.1995 400 Commonwealth Drive, Warrendale, PA 15096-0001 U.S.A. Tel: (41 2)776-4841 ~ax:(412)776-5760 Downloaded from SAE International by North Carolina State Univ, Sunday, September 16, 2018The appearance of the ISSN code at the bottom of this page indicates SAE's consent that copies of the paper may be made for personal or internal use of specific clients. This consent is given on the condition, however, that the copier pay a$5.00 per article copy fee through the Copyright Clearance Center, Inc. Operations Center, 222 Rosewood Drive, Danvers, MA 01 923forcopying beyondthat permitted by Sections 107 or 108 of the U.S. Copyright Law. This consent does not extend to other kinds of copying such as copying for general distribution, for advertising or promotional purposes, for creating new collective works, or for resale. SAE routinely stocks printed papers for a period of three years following date of publication. Direct your orders to SAE Customer Sales and Satisfaction Department. Quantity reprint rates can be obtained from the Customer Sales and Satisfaction Department. To request permission to reprint a technical paper or permission to use copyrighted SAE publications in other works, contact the SAE Publications Group. All SAE papers, standards, and selected books are abstracted and indexed in the Global Mobility Database. No part of this publication may by reproduced in any form, in an electronic retrieval system or otherwise, without the prior written permission of the publisher. ISSN 0148-71 91 Copyright 1995 Society of Automotive Engineers, Inc. Positions and opinions advanced in this paper are those of the author(s) and not necessarily those of SAE. The author is solely responsible for the content of the paper. A process is available by which discussions will be printed with the paper if it is published in SAE transactions. For permission to publish this paper in full or in part, contact the SAE Publications Group. Persons wishing to submit papers to be considered for presentation or publication through SAE should send the manuscript or a 300 word abstract of a proposed manuscript to: Secretary, Engineering Activity Board, SAE. Printed in USA go-1203~1~~ Downloaded from SAE International by North Carolina State Univ, Sunday, September 16, 2018Modeling of Heat Transfer and Fluid Hydrodynamics for a Multidisc Wet Clutch Yubo Yang, Robert C. Lam and Yih Fang Chen Borg-Warner Automotive Hiroshi Yabe NSK-Warner Abstract A Mathematical model describing the heat trans- fer and fluid hydrodynamics during the engagement cycles of "wet" clutches have been developed. The model equations of heat balance for the separator, friction materials, core plate, and automatic trans- mission oil (ATF) or air in the clearance between separators and friction materials were formulated. The momentum balance for ATF flow in the fric- tion lining (porous medium) during the engagement was considered. Proper boundary conditions at the interface and boundary conditions at the inner and outer radius of the clutches were accounted for. The model includes the simulation of engagement cycles for both the traditional (two-sided) wet clutches and the single-sided wet clutches. Many important phe- nomena which were not investigated before, such as non-uniform contact between separators and fric- tion materials, ATF flow into the friction materials due to liquid permeability, compressibility of fric- tion materials, effects of separator splines, and ef- fects of rotational speeds, etc, were included in the present model. The effect of various