The aerodynamics of non-box trailers were neglected for a long time; yet field research shows that this segment accounts for a substantial share of total heavy vehicle kilometres and that the improvement potential remains large.
Priorities on the Silo Trailer
The cylindrical body is a good starting point in terms of airflow; the problem lies in the attachments. Discharge pipes, ladders, the top walkway platform and the valve group create islands of turbulence around the clean body. Recessing this equipment into the body line or enclosing it with covers, combined with a side skirt, delivers a meaningful gain.
Priorities on the Tipper
The open body mouth acts almost like an air brake at high speed. Automatic sheeting systems are critical not only for load security but also for aerodynamics: a taut, closed sheet cuts in-body turbulence to a large extent. Aligning the front wall with the tractor cab and tidying the underbody with short skirts are the remaining gain items.
- Fair in or recess all attached equipment in the direction of flow
- Keep the sheet closed on every trip, even on empty returns
- Short, durable side skirts suit site conditions
- Update the tractor spoiler setting to match the body height
References
- Durbin, T. D., Johnson, K. C., Jung, H. & Miller, J. W. (2021). Characterizing non-box trailer activity and aerodynamic devices for greenhouse gas emissions reductions. Transportation Research Part D: Transport and Environment, 98, 102763. DOI: 10.1016/j.trd.2021.102763