Study: Don-Bur Teardrop cuts fuel costs
Trailer manufacturer Don-Bur has highlighted the results of a new study by the University of Surrey, which investigated the drag reduction credentials of its Teardrop trailer.
The project, which was carried out by Andrei Stylianou and utilised SimScale Computational Fluid Dynamics, compared the performance of a Teardrop hauled by an articulated lorry against that of a 4.1m-high standard box van trailer.
It recorded an aerodynamic drag reduction of 15 per cent, and an expected reduction in fuel consumption of seven per cent.
At today’s bulk diesel prices, based on average consumption, this could save an operator £2,183, said Don-Bur, as well as yielding a 6.3-tonne reduction in CO2 per annum.
Previously, the manufacturer had only collated results from real-world proving ground and operator trials, but said numerous variables could skew such results, prompting a more scientific approach.
According to the study, the key mechanism of the Teardrop trailer’s success was: “keeping the main flow attached to the roof of the trailer and directing the upper shear layer downwards towards the ground. This effectively reduces the size of the wake by improving velocity recovery.”
The report found: “Qualitative analysis of pressure distribution showed a significantly larger pressure recovery in the wake region of the Teardrop trailer, responsible for the drop in pressure drag, and hence the drag coefficient, when compared to the conventional trailer.”
For the standard trailer, the length of absolute wake was 3.03m, whereas the Teardrop only had a wake length of 2.09m.
The project also simulated additional roof camber (curved slope) variations to assess the capacity for further savings, but the analysis suggested that the Teardrop’s drag reduction capabilities appeared independent of the curve.
Don-Bur said the study had helped underpin the logic behind return on investment (ROI) calculations for the Teardrop.
“Unless backed by proven results, it is often counterintuitive to invest money to save money,” said Richard Owens, Don-Bur marketing manager.
“It simply feels more natural to spend less. We feel, however, that this independent scientific study goes a long way to providing the proof required to encourage further investment into this award-winning green technology.”
