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Fluid thinking
Page 46
Page 47
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Operators want products that cut fuel use and carbon footprints. Body and trailer manufacturer Cartwright Group is harnessing Formula 1-style technology to meet those demands.
With dieseln • With dieseln •
pces on the up, operators are demanding truck and trailer-makers help reduce both fuel use and their carbon footprint and that means developing ever-better aerodynamic products.
For its part. Cheshire-based body and trailer manufacturer Cartwright Group has adopted computational fluid dynamics (CFD), more commonly associated with Formula 1 racing teams, to improve the aerodynamics of its products.
Cartwright Group has linked up with Manchester Metropolitan University, through a knowledge transfer partnership (KTP), to develop trailers using CFD.
Director Steven Cartwright explains: "CFD has replaced the windtunnel. All the Fl teams use it."
Desktop approach He continues: -By using particles, which you can alter in size, it shows up where the aerodynamic deficiencies are on the product. We have a guy here doing his doctorate through KTR He is using CFD on road transport products such as the Cheetah [trailed: we have drawn it up and put into the program to see where it can he improved.
Cheetah uses a lip on the tractor's air management kit to push air out: it has thin trailer sideskirts with a clear underneath though the running gear, rounded capping and circular rear under-run bar, to help guide air through cleanly.
Adopting a desktop approach to aerodynamics also reduces costs. Cartrwieht says: "When we first did the Department for Energy testing with Cheetah in 1990, the windtunnel was the cheapest way.
"Back then, CFD was just getting there, but it was very expensive. Now, it's the other way around, [the] windtunnel is the high-cost option."
Fastback
The first result of CFD is the new — soon-to-be-launched — Cheetah Fastback trailer, which adopts a variable air suspension syslcm that lowers the running height of the trailer to reduce drag.
"It's a straight-frame trailer with a valve to lower the chassis— this is where we have been a bit unique.he says. "It uses a wedge-shaped chassis and the roof line drops down to suit the shape of chassis.
The first two 4.0m-high Cheetah Fastback trailers will go into operation with TNT in Germany and Holland. •