This is the second instalment of a two-part article on truck drag reduction.

TotalSim recently attended the Multimodal Logistics show where we were exhibiting with Hilton Docker, who specialise in GRP mouldings and truck fairings.

It became apparent at the show that there is a huge desire to save drag and money within the industry.

In Part 1, TotalSim introduced a fairing and a modified wing mirror/turning vane with large drag reductions.

TotalSim decided to test some increasingly common trailer modifications to see their effect upon drag.

The TotalSim process began with the scan of a MAN truck and trailer (OK so it was only at model scale, but it will be good enough for the demonstration).  TotalSim’s in house scanning team set about scanning the truck and trailer. The trailer was then put through our optimisation software Sculptor which deformed the trailer to produce over 30 variations including the recently popular teardrop shape manufacturers are choosing to adopt. These were then run through our CFD (Computational Fluid Dynamics) software, to determine the amount of drag they were generating.

In the first case of significance we lowered the leading edge of the trailer and raised a point midway on the trailer giving the top edge a teardrop shape, a design seen an increasing amount on the roads in the UK. The effect however was minimal and resulted in a drag reduction of only 1% for a similar payload.

In the second case we lowered the leading edge further still so that it was flush with the cab and lowered the trailing edge. In this case we saw a much more significant drag reduction of 15% but it would result in the loss of payload.

To us at TotalSim this raises a question of the effectiveness of the costly procedure of manufacturing these bespoke designs. The loss of space within the trailer and non uniform spaces offset the potential cost savings from drag reduction.

When compared with the significant reductions in drag produced by the relatively straightforward procedure of adding a fairing to the cab as seen in our previous article, it does pose the questions why you would take this route until you have already benefited from the drag reductions in Part 1.

The industry is calling out for a revolution to make huge step changes in the aerodynamic efficiency of vehicles.   Whilst we wait for this to happen with minimal effort huge drag savings can still be achieved with the simple and cost effective devices shown in part 1.

If you are interested to find out more about how TotalSim can help reduce the drag on your vehicles or fleet then please contact us.

Working with Hilton Docker Mouldings, we now also have a partnership where our virtual optimisation can then be converted to the real world.