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DON-BUR · 10-06-2009, 05:50 AM

My name is Richard Owens and I represent DON-BUR, the manufacturers of the commercial Teardrop trailers.

We have done considerable work on the shaping of these vehicles and I wanted to clarify a few points.

1) The UK standard height for a trailer 4.2m. The Teardrop standard is 4.5m - a 300mm increase in height and proportionate frontal area. Since the initial launch, we have now improved the range of Teardrop designs, catering for European/US height limits of 4m. This newer option has no increase in projected frontal area and capacity has been maintained by dropping the floor.

2) The shape, or profile is critical to the Teardrop's success. As some of you have noted, we have not simply added a "hump", as this would purely add to frontal area and the CD reduction would not be significant enough to outweigh the height increase. We have to consider the entire combination before setting heights: the cab top deflector and front edge of the trailer have to be set at the correct height to maintain a clean line (usually lower by 200mm). The rear "top header" is positioned much lower than normal, which reduces the wake considerably. Further investigation is underway to include "boat tails" to the rear which will improve this further.

3) The belief that a standard trailer has little airflow separation is completely inaccurate. There are several areas of significant seperation including top edge of tractive unit, tractor-trailer gap, trailer leading edge, trailer side leading edges, under chassis, rear. As you all understand, the Teardrop shaping on the roof is a fairly simple common-sense approach to an age old problem. We would also have liked to taper the sides in at the rear but commercial requirements prevent this from being practical.

Interest in the Teardrop trailer is now increasing exponentially and globally. We have interests from major US operators, as well as interest from Europe, Eastern Block and Australia.

We are delighted that it should be such a hot topic for debate but also feel it is a solution that was long over-due.

Richard

10-06-2009, 05:50 AM	#36 (permalink)
DON-BUR EcoModding Lurker Join Date: Oct 2009 Location: Stoke-on-Trent, UK Posts: 8 Thanks: 2 Thanked 6 Times in 2 Posts	My name is Richard Owens and I represent DON-BUR, the manufacturers of the commercial Teardrop trailers. We have done considerable work on the shaping of these vehicles and I wanted to clarify a few points. 1) The UK standard height for a trailer 4.2m. The Teardrop standard is 4.5m - a 300mm increase in height and proportionate frontal area. Since the initial launch, we have now improved the range of Teardrop designs, catering for European/US height limits of 4m. This newer option has no increase in projected frontal area and capacity has been maintained by dropping the floor. 2) The shape, or profile is critical to the Teardrop's success. As some of you have noted, we have not simply added a "hump", as this would purely add to frontal area and the CD reduction would not be significant enough to outweigh the height increase. We have to consider the entire combination before setting heights: the cab top deflector and front edge of the trailer have to be set at the correct height to maintain a clean line (usually lower by 200mm). The rear "top header" is positioned much lower than normal, which reduces the wake considerably. Further investigation is underway to include "boat tails" to the rear which will improve this further. 3) The belief that a standard trailer has little airflow separation is completely inaccurate. There are several areas of significant seperation including top edge of tractive unit, tractor-trailer gap, trailer leading edge, trailer side leading edges, under chassis, rear. As you all understand, the Teardrop shaping on the roof is a fairly simple common-sense approach to an age old problem. We would also have liked to taper the sides in at the rear but commercial requirements prevent this from being practical. Interest in the Teardrop trailer is now increasing exponentially and globally. We have interests from major US operators, as well as interest from Europe, Eastern Block and Australia. We are delighted that it should be such a hot topic for debate but also feel it is a solution that was long over-due. Richard Last edited by DON-BUR; 10-06-2009 at 08:21 AM..