SPH-Based Local Lubricant Availability Assessment and Candidate-Region Screening for Oil Suction Port Placement Under Continuous Maneuvering

In aviation lubrication systems, changes in lubricant flow and spatial distribution under different operating conditions can affect lubricant delivery and lubrication performance. Existing studies have used flow variables such as velocity and pressure, together with instantaneous spatial distributions, to characterize flow states. Although these quantities can effectively characterize flow states and their evolution, they are often difficult to directly translate into quantitative evaluation results for structural design, comparison of different configurations, and engineering decision-making. To address this issue, a local lubricant availability assessment and candidate-region screening approach is developed based on smoothed particle hydrodynamics (SPH) simulation results. Low-percentile availability A5, minimum availability Amin, and the longest continuous low-oil duration L50 are jointly used to assess the local lubricant state at different spatial locations. An aviation lubricant tank is considered as the application case, and local lubricant conditions under different initial oil volumes and baffle configurations are compared under identical maneuvering conditions. The results show that, within the investigated volume range, the initial oil volume is closely related to the local lubricant state and the extent of the candidate region. As the oil volume decreases, local lubricant deficiency becomes more pronounced, and the differences among baffle configurations become more evident. At an initial oil volume of 10 L, the cross-baffle configuration provides the largest candidate-region area ratio among the four configurations, reaching 59.39%, compared with 4.19% for the no-baffle case. The proposed framework translates transient flow differences under different operating conditions and structural configurations into spatially explicit candidate regions, providing a quantitative basis for preliminary oil suction port placement.