## 6 Conclusions  
sCO\({}_{2}\)-lubricated TPJBs enable a simple configuration of turbomachinery for sCO\({}_{2}\) power cycles by eliminating not only the issue of mixing-up of oil lubricant and sCO\({}_{2}\) process fluid but also the need for oil pumps and sealing devices for the lubricant. The present study develops a computational model for sCO\({}_{2}\)-lubricated TPJB with hydrostatic pressurization at the tilting pad recesses to improve its static and dynamic performances. The finite element and finite difference methods solve the Reynolds and energy equations for the pressure and temperature distributions, respectively. The Newton-Raphson method is employed to find the equilibrium position, and the successive substitution method finds the numerical solution for the local density and viscosity of sCO\({}_{2}\), which depend nonlinearly on pressure and temperature. The models for the density and viscosity of sCO\({}_{2}\), hydrodynamic lubrication with compressible and incompressible fluid flows, and hydrostatic lubrication with a turbulent flow and high Reynolds numbers are validated by comparing their results with predictions and test data in the literature. A parametric study of the hybrid TPJB reveals that an increase in supply pressure significantly increases the pad pressure. At a rotor speed of 60 krpm, with an increase in supply pressure, the journal eccentricity decreases by 65%, and the minimum film thickness increases by 80%, thus enhancing the load capacity compared to that of the hydrodynamic TPJB. Hydrostatic pressurization has the most significant effects on the load capacity at the lowest rotor speed, where hydrodynamic pressure generation is the lowest. The stiffness coefficients increase, but the damping coefficients decrease owing to external pressurization. For the hybrid TPJB, with an increase in the supply pressure, the stiffness significantly increases, but the damping coefficients change slightly. Conceptualization, S.M.M. and T.H.K. ; methodology, S.M.M. ; model development, S.M.M. ; formal analysis, S.M.M. ; writing--original draft preparation, S.M.M. ; writing--review and editing, T.H.K. ; supervision, T.H.K. ; project administration, T.H.K. ; funding acquisition, T.H.K. All authors have read and agreed to the published version of the manuscript. This study was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea Ministry of Science and ICT (MSIT) (No. NRF2021R1F1A105960211), \"Feasibility Study on High-Speed, Long-Life Bearing-Seal Units in Turbopumps for Small Reusable Liquid-Propellant Space Launch Vehicles\" and the Korea Energy Technology Evaluation and Planning (KETEP) grant funded by the Korea Ministry of Trade, Industry and Energy (MOTIE) (No. 2021202080026D), \"Development of Infrastructure/Platform Technology and Operation Management System for AI/ICT-Based Variable Fluid Device Design and Condition Diagnosis.\"  
Not applicable. Figure 16: Damping coefficient vs. rotor speed for increasing supply pressures. Static load = 100 N.  
**Acknowledgments:** This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea Ministry of Science and ICT (MSIT) (Grant No. NRF2021R1F1A105960211) and the Korea Energy Technology Evaluation and Planning (KETEP) grant funded by the Korea Ministry of Trade, Industry and Energy (MOTIE) (Grant No. 2021202080026D). The first author acknowledges the support of the Global Scholarship Program for Foreign Graduate Students at Kookmin University, South Korea. **Conflicts of Interest:** The authors declare that they have no conflicts of interest. **Nomenclature**