Nanoparticle-enhanced Lubrication: CFD Insights into Cavitation in Three-lobe Journal Bearings Using TiO2 Nanofluids

Three-lobe journal bearings are widely utilized in high-speed rotating machinery due to their superior dynamic stability and load-carrying characteristics. However, they are prone to vapor cavitation in the diverging regions, which can degrade lubrication performance and operational reliability. The present research focused on a comprehensive numerical investigation of pressure distribution and cavitation behavior in three-lobe journal bearings operating at 500 rpm, using both conventional base oil (Mobil DTE 24) and a nano-lubricant formulated with 0.5 wt. % titanium dioxide (TiO2) nanoparticles. Simulations were performed using the Zwart–Gerber–Belamri (ZGB) cavitation model within a multiphase CFD framework in ANSYS Workbench 2024R1. The analysis focused on comparing pressure profiles under both cavitating and non-cavitating conditions. The results indicated that the TiO2 nano-lubricant significantly enhanced bearing performance by increasing peak pressure by up to 50% and improving load-carrying capacity by approximately 36–40% compared to the base oil. Under cavitating conditions, the nano-lubricant suppressed vapor formation by increasing the minimum pressure from –0.45 MPa to –0.13 MPa, indicating a 70% reduction in cavitation intensity compared to the base oil. Under non-cavitating operation, the TiO2 nanofluid also demonstrated 10–20% better pressure uniformity and film stability, which contributed to reduced friction losses and improved lubrication reliability. Overall, the findings validated the tribological potential of TiO2-based nano-lubricants as an environmentally friendly and performance-enhancing alternative to conventional lubricants in hydrodynamic bearing applications.