## 3 Research Results and Discussion
### Discussion  
One of the major aims of this research is to control the hydrostatic water film thickness in a proper range because there is extremely limited assembly space for WSSCs. The results indicate that as water injection pressure increases, the bearing capacity of the HTB increases. The supply flowrate increases with an increase in water film thickness and water injection pressure. According to the hypothesis (presented at the beginning of the third section), this study only involves the simulation of steady lubrication states under different constant force loads acting on an HTB. However, force loading, hydrostatic water film and film pressure, among others, are constantly changing in the practical operation of WSSCs. The pulsation frequency of their loading force is approximately 200-400 Hz. To describe this unsteady lubrication state, an evaluating method of maximum and minimum values, which is well-known as the \"squeeze effect\" in a narrow clearance flow of a fluid, is used. When the load on an HTB increases, the hydrostatic lubricating film, \(h\), becomes thinner. This \"getting thinner\" has an effect that is a reaction against getting thinner. However, when the load on HTB decreases, the hydrostatic lubricating film, \(h\), becomes thicker. Accordingly, this \"getting thicker\" has an effect that is a reaction against getting thicker. A steady hydrostatic water film, \(h_{\text{min}}\), under a constant maximum load, \(W_{\text{max}}\), must be the limitation of pulsating hydrostatic water film under the changing load that does not exceed \(W_{\text{max}}\). Similarly, a steady hydrostatic water film, \(h_{\text{max}}\), under constant minimum load, \(W_{\text{min}}\), must be the limitation of a pulsating hydrostatic water film under the changing load, which is not as low as \(W_{\text{min}}\).  
Both simulation and experimental results show that the newly proposed structure of the HTB can meet the requirements of loading pulsating gas force within the allowable clearance range of the WSSC. The comparison of the water consumption of the two types of HTB shows that the new structure is more water-efficient. For star wheel bearings, it is necessary to consume less water while maintaining its stability because the liquid supply  
Figure 14: Comparison of the water supply for (**a**) annular groove vs. crossing groove (simulated results), (**b**) crossing groove (simulated results vs. experimental results).  
of the single-screw compressor is limited. All the above means that the new modification is suitable for the star wheel shaft of WSSCs. The steady-state hydrostatic lubrication simulating model developed in this study can be used to determine HTB sizes and its water injection pressures for WSSCs. When a bearing designed in this manner is implemented, its water lubrication films will be in the range of \(\rm{h_{min}}\) to \(\rm{h_{max}}\).  
Accordingly, there is no sudden change in the thickness of the water film because the force changes continuously and periodically when the discharge pressure of the WSSC remains unchanged. In experiment, all data were measured and collected after the system ran stably, and the water film thickness in the bearing clearance would fluctuate at the same frequency as the force fluctuated. The deflection of the component caused the oscillation in the direction of water film thickness, but its frequency was different from the fluctuation frequency of force. During data processing, the signal data with the same frequency of components deflection were isolated from the original data by FFT in Mathcad software. Finally, data regarding the water film thickness were obtained by IFFT.  
In the numerical simulation, it was assumed that water did not slip on the bearing surface. However, in the experiment, due to the low viscosity of water, the water velocity near the surface of the HTB ring may be different from the bearing speed.