# A New Multi-Physics Coupled Method for the Temperature Field of Dry Clutch Assembly
## 3 Multi-Physics Coupled Simulation
### Temperature Field of the Clutch Assembly during the Last Engagement  
In the last engagement-disengagement process, namely the 45 th cycle, the temperature of the assembly is above 350 \({}^{\circ}\)C. Consequently, the contact pressure distribution on the friction surface of the pressure plate is mainly concentrated at the middle diameter position, while the outer and inner diameters do not make contact due to the curved thermal deformation. The following Figure 14 illustrates the contact gap (a) and contact pressure  
\begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \hline
**Conditions** & \multicolumn{4}{c}{**Engagement + Synchronization Stage**} & \multicolumn{4}{c}{**Disengagement Stage**} \\ \hline Monitoring & \multicolumn{8}{c}{Outer Diameter Point} \\ Point & \multicolumn{8}{c}{Outer Diameter Point} \\ \hline Time/s & 0.5 & 1.0 & 1.5 & 2.0 & 2.5 & 3.0 & 8.0 & 13.0 & 18.0 & 23.0 & 28.0 \\ Measured Temperature/\({}^{\circ}\)C & 17.68 & 22.33 & 49.43 & 89.73  
(b) contour plots on the friction surface of the pressure plate during the last engagement-disengagement process. These display a non-uniform distribution of contact pressure on the friction surface of the pressure plate, directly resulting in a non-uniform heat flux density distribution on the friction surface.  
The temperature field distribution of the assembly during the last engagement is shown in Figure 15. It can be observed that after undergoing 45 consecutive engagement and disengagement processes, the overall temperature of the dry clutch assembly greatly increases. The middle-diameter region of the pressure plate friction surface exhibits a significant high temperature. Correspondingly, the friction disc friction surface also shows a higher temperature in that area. The temperature rises in the outer diameter regions of both the pressure plate and the friction disc, which are relatively small. In the final  
Figure 14: Contact gap map (**a**) and contact pressure map (**b**) on the friction surface of the pressure plate during the last engagement sliding phase.  
engagement and disengagement process, the peak temperature reaches 426.43 \({}^{\circ}\)C. Even after 26 s of heat dissipation during disengagement, the highest temperature remains at 301.82 \({}^{\circ}\)C.  
Figure 16 shows the temperature profiles of the simulation and the test for the last cycle at the points of (a) the inner diameter, (b) the middle diameter, and (c) the outer diameter, respectively. It can be seen from Figure 16 that for these three monitor points, the temperatures of the simulation agree well with those of the test generally.  
Table 5 shows the comparison of the temperature between the simulation model and the test rig for the 45 th engagement and disengagement processes. It can be seen from Table 5 that for the last engagement-disengagement process, the temperature difference at the outer diameter point of the pressure plate reaches a maximum of 9.31 \({}^{\circ}\)C with a relative deviation of 4.99%. The average deviations of the simulated results for the outer, middle, and inner diameter monitoring points are 1.98%, 0.88%, and 1.05%, respectively. By analyzing both the initial low-temperature process and the final high-temperature process, it can be concluded that the simulated temperature curves for the three monitoring  
Figure 15: Temperature field of the clutch during the 45 th engagement. (**a**) the temperature contour map of the dry clutch assembly. (**b**) the temperature contour map of the pressure plate’s friction surface. (**c**) the temperature contour map of the friction disc’s friction surface.