Advancing Electric Drive Unit Design with Smoothed Particle Hydrodynamics (SPH).

The performance of Electric Drive Units (EDUs) in electrified powertrains heavily depends on efficient thermal and lubrication management. Accurate assessment of lubrication flow, particularly in terms of wettability and churning losses, is essential for optimizing EDU performance across various driving conditions. This paper presents a comprehensive numerical investigation of lubrication flow behavior within an EDU using an advanced Smoothed Particle Hydrodynamics (SPH) method. The mesh-free SPH approach provides significant advantages in modeling intricate oil dynamics, such as oil splashing, and the behavior of oil in contact with rotating components. The primary focus of this study is to investigate the phenomena of splashing, wettability, and churning losses under various operating conditions within the gearbox environment. Key flow characteristics such as oil distribution, particle trajectories, torque resistance due to fluid drag, and oil volume fraction are analyzed under varying operational parameters. The EDU design is then refined through multiple iterations using the SPH method to enhance splashing characteristics and improve wettability performance for critical components. This work demonstrates the effectiveness of the SPH method as a robust virtual prototyping tool for next-generation EDU lubrication system design.