# Multiphase Conjugate Heat Transfer Analyses on the Assembly Situation of Rotary Shaft Seals
## 2 Materials and Methods
### Case Studies
#### 2.3.1 Variants with Additional Elements  
To protect the sealing edge from penetrating liquids or contamination, an additional slinger disc can be installed. Baffle plates are used to intercept and control large volumes of oil or dirt and thereby prevent damage to the sealing lip. Studies by [PERSON] [38] have shown that components surrounding the sealing system, for example, bearings, slinger discs or baffle plates, have an influence on the temperature in the sealing contact. Therefore, different combinations with additional elements close to the sealing edge were simulated. These configurations with additional elements are listed in Table 2.  
The computer-aided designs (CAD) of the first four variants in Table 2 are shown in Figure 5. For the variants with a baffle plate, seen in Figure 5c,d, the volume between the baffle plate and the cover was not considered in the simulations. The boundaries to this volume are adiabat. Two different arrangements of tapered roller bearings, the X-arrangement and the O-arrangement, ball bearings and cylindrical roller bearings were tested on the test bench. The sectional views of the geometries of the four-bearing arrangements are shown in Figure 6. The diameter of the bearings was the same for all four.  
The maximum temperatures, which are the main focus of the simulation, were found in the contact area between the sealing ring and the shaft. Due to the distance to the contact area, the geometry of the bearings was assumed to have no great influence on the contact temperature. Thus, to keep the simulation setup as simple as possible, the same geometry model was used for the simulations of the four variants with bearings, as shown in Figure 7.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**Designation**} & \multirow{2}{*}{**Bearing**} & **Slinger Disc:** & **Baffle Plate:** \\  & & **Inner Diameter** & **Outer Diameter** \\ \hline SD\_small & - & 93 mm & - \\ SD\_large & - & 87 mm & - \\ BP\_small & - & (78.7 mm) & 93 mm \\ BP\_large & - & (78.7 mm) & 87 mm \\ Bea\_X & tapered roller bearing, & - & - \\ Bea\_O & X-arrangement & & - \\ Bea\_Ba & balanced ball bearing & - & - \\ Bea\_Cyl & cylindrical roller & - & - \\ \hline \hline \end{tabular}
\end{table}
Table 2: Simulated variants with additional elements.  
Figure 5: Simulated configurations with slinger disc and baffle plate. (**a**) SD\_small. (**b**) SD\_large. (**c**) BP\_small. (**d**) BP\_large.  
Figure 6: Geometry of the bearing arrangements. (**a**) X-arrangement. (**b**) O-arrangement. (**c**) ball bearing. (**d**) cylindrical roller.  
Different pumping effects could be observed for different bearings. In the case of the tapered roller bearings, the fluid was pumped towards the larger diameter of the taper [39]. In the X-arrangement, the fluid located between the sealing ring and the bearings was pumped away from the sealing ring. In the O-arrangement, the fluid was pumped towards the sealing ring. For the variants with bearings, there were two fluid domains filled with oil and air: the domain _oil chamber_ and the domain _oil chamber bearing_. Depending on the bearing and its pumping effect, a different amount of oil reached the domain _oil chamber bearing_. Thus, the only differences between the variants with bearings were the following:  
* The oil fill level \(h_{oil}\) in the domain _oil chamber bearing_;
* The frictional torque between the bearing and the shaft.  
The fluid domain _oil chamber bearing_ was filled with oil up to the oil fill level \(h_{oil}\); everything above this level was initially assumed to be air.