2026-10-14T13:23:47Z https://www.scidb.cn/oai

10.57760/sciencedb.0102d 2026-08-24T16:29:03Z

2026-08-24 Numerical investigation on no-load loss reduction in electric vehicle gearbox by surface wettability modification doi:10.57760/sciencedb.0102d en High no-load losses during high-speed cruising impair the range performance of electric vehicles. To address the issue, a drag reduction (DR) strategy based on an oleophobic coating is applied to an engineering grade electric vehicle gearbox (EVG), and a component to vehicle energy-saving evaluation chain is established. A decomposition framework is then established to isolate churning loss from total no-load loss and quantify the coating effect. A combined experimental and numerical approach is then adopted. A splash-lubricated EVG model is built using the Moving Particle Semi-Implicit (MPS) method. The model resolves how the flow field, pressure field, and oil coverage rate evolve with rotational speed. The model is validated step by step using a rotating disk rig, a transparent case gearbox rig, and a high speed EVG rig. Surface characterization shows that the coating forms a nanoscale rough surface on the gear end faces. The measured oil contact angle increases from 7.8° to 52.7°, and the oleophobicity is retained after abrasion. The experiments show that the coating reduces the churning loss by approximately 17.3% to 52.3% over the 500 to 10000 r/min range. The MPS simulation shows that the peak oil pressure in the meshing zone is lowered by 41.3%. Finally, the measured power saving ΔP0 is mapped onto the WLTC using the proposed model. This mapping yields a cumulative energy saving of about 122 Wh per cycle. The driving range extension is concentrated in the medium and high speed range. Nano-composite ceramic coating; Churning loss; Drag reduction; Electric vehicle; Gearbox; MPS Yi Liu PUBLIC https://creativecommons.org/licenses/by-nc-nd/4.0/ dataset Science Data Bank