This research involved the development and verification of a comprehensive heat transfer model for a multiple-plate wet clutch. The model allows the prediction of clutch plate and oil temperatures for a wide variety and range of operating conditions. The model allows for the evaluation and analysis of potential design changes such as oil flow rate, plate properties, and oil properties.; Three specific operating conditions were considered: (1) engaged and slipping, (2) engaged and not slipping, and (3) disengaged. The heat transfer was modeled as forced convection with the main thrust of the research being the determination of a model for the coefficient of convective heat transfer.; Three distinct models for the coefficient of convective heat transfer were developed for the three operating conditions considered. All three models are based on modeling the Nusselt number as a function of the Reynolds number and Prandtl number. All of the models were of the form: Nusselt = A0 Reynolds{dollar}sp{lcub}rm A1{rcub}{dollar} Prandtl{dollar}sp{lcub}rm A2{rcub}{dollar}. Each of the three major operating conditions had its own set of model equation coefficients A0, A1, and A2.; The Reynolds number in the above equation is defined to be based on the flow velocity of the cooling oil. Neither the plate velocity or the unit shear on the plates provided substantial improvements in the model for the coefficient of convective heat transfer.; The models for the coefficient of convective heat transfer were used in conjunction with an overall heat transfer model to determine clutch plate and oil temperatures. The overall heat transfer model assumed that all of the heat dissipated in the clutch was absorbed in the separator plates and then transferred to the cooling oil. It was determined that the effective plate mass had to be considered to be about 50 percent greater than the actual mass for the model to be reasonably accurate.; The overall heat transfer model provided good estimates of the measured clutch temperature for a wide variety of operating conditions considered. The estimated clutch plate temperature was typically within 20 degrees F of the measured temperature. The model provided the best estimates for the engaged and not slipping condition, followed by the engaged and slipping condition, and then followed by the disengaged condition.
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