Characterisation of the Tyre Spray Ejected Downstream of a Bluff Automotive Body
2022-01-1074
03/29/2022
- Event
- Content
- A substantial obstacle to the widespread adoption of autonomous vehicles is the perception of safety and reliability. Safe operation relies on an increasing array of sensors, the performance of which may be impaired by both airborne spray and direct obstruction. This necessitates increased consideration of both tyre spray and surface contamination throughout the automotive design process. Existing work has shown spray entrainment to be an unsteady problem, but typical experimental investigations of front-end contamination and wiper performance have utilised fixed spray grids. Such methods do not replicate the turbulence generated by preceding vehicles and may, therefore, be a poor representation of third-party contaminant sources. This paper presents an investigation into the effect of rear-end geometry changes on the spray ejected downstream of a bluff automotive body (the Windsor Model). A quarter-scale variant of the model is studied in the Loughborough University Large Wind Tunnel. UV-doped water is ejected from behind the contact patch of the rear-left wheel, allowing for the assessment of mass build-up on the rear of the vehicle. In addition, planar imaging is employed to investigate the distribution of particles passing through multiple planes downstream of the vehicle and identify the unsteady motions within the resultant spray cloud. This data will serve as validation for future numerical investigations. Initial computational results show a 20% reduction in rear-end contamination coming from the inclusion of 20° rear-end side tapers. Further simulations will directly relate airborne spray to sensor output and study the front-end contamination originating from unsteady third-party sources.
- Citation
- Crickmore, C., Garmory, A., and Butcher, D., "Characterisation of the Tyre Spray Ejected Downstream of a Bluff Automotive Body," SAE Technical Paper 2022-01-1074, 2022, .