A Combined Theoretical and Experimental Investigation of the Overall Energy Consumption in a Wet Dual Clutch System During a Driving Profile

Abstract

Abstract Reduction of the energy consumption and increase of the energy efficiency of the wet dual clutch system are important factors for vehicle transmission improvement. The demand of a precise investigation of the overall energy consumption in the clutch system has therefore increased significantly. A wet dual clutch system represents in this paper dual clutch packs and their electro-hydraulic system. The energy, which is not efficiently transferred in the power flow path but consumed in the wet dual clutch system, is considered here as the energy consumption. The possible energy consumption in the wet dual clutch system are hydrodynamic drag torques between the disengaged discs, frictional torques during the clutch engagement and electro-hydraulic energy usage for actuating and cooling systems. The aim of this paper is to evaluate the energy consumption in a whole wet dual clutch system at the system level. Firstly, due to lack of experimental data on the system level, all the available analytical models for predicting the hydrodynamic drag torque are analyzed and compared based on the varied influential parameters. The energy dissipation mechanisms in the clutch engaging phase and the energy usage in the electro-hydraulic system are explained based on the measured signals. One driving profile is applied here and the hydrodynamic energy dissipation is calculated with the chosen analytical model, while the other energy usage in the wet dual clutch system is analyzed with the measured signals. Based on the evaluation on the system level, the majority of the energy is dissipated in the clutch packs for reducing the relative speed, while the energy usage in the actuating system comes next. The hydrodynamic energy losses and the consumption in the cooling system share the lowest proportion.