Renovation and aerodynamic improvement of a BPW closed trailer

[Christophe]

What do you think the safety load I put in is? 38 kg of battery!

[gildas]

A paramotor well laid flat + accessories that will be well secured...

There are electric paras, so batteries are planned.

[Christophe]

Yes there are electric paramotors, indeed: https://dragonfly-paramotor.fr/article- ... nouvelles/

Here the trailer of this page reminds me of something...

[gildas]

Nice initiative this Dragonfly! It must be day and night in terms of motorization!
No noise and no stinky smoke from a 2-stroke engine...

A propeller strapping (on a boat) if that can inspire you...

[Christophe]

As I have a little margin in terms of weight and thanks to the aerodynamic tilting torque, I decided to finally make the rear floor hard...

10 mm of plywood from the old doors / front partition + 3.6 mm from the offcuts of the 2 partitions... you just won't have to walk everywhere

[Remundo]

I found a fun article


But contrary to what I thought... it's not about improving the Cx, but about "raising" the truck!

. It consists of installing a wind turbine on the roof of the truck which works the mass of air displaced by the truck to lower its weight.

At any time during the journey, software analyzes in real time the aerodynamic modifications of the vehicle in motion to optimize its mass. According to the company's initial estimates, a truck's fuel consumption could be reduced by 25% if it travels between 80 and 100 km/h. During the first tests, the system would not have had a negative effect on the maneuverability of the trucks.

These brave people are very optimistic!
If it is true that weight generates consumption via the tires, the pneumatic drag power is quickly negligible in front of the aerodynamic drag, in particular at 90 km/h

For example for a 20 tons with a pneumatic resistance coefficient of 0,005 and an Scx of 10m² at 25 m/s
* Crrxmxg=981N
* 1/2 ro SCx v² = 3750 N

In addition, the proposed system precisely degrades the aerodynamic drag.

Finally, cornering handling will also be degraded.

In reality the first thing to do is to streamline the truck by closing the Q to glue the flow lines and at the front with a very rounded nose.

Why not create lift, but that does not intervene strongly, and above all this lift must not generate additional aerodynamic drag.

[Remundo]

after reflexion...

a good manufacturing/aero compromise would be to make the rear triangular.

I was reading the wiki article and at the end, an eloquent experience:

and we can never talk enough...

[Obamot]

But contrary to what I thought... it's not about improving the Cx, but about "raising" the truck!

And this increase in the gauge in height, to pass under the bridges? Muarf......

[Christophe]

This Startup should hire me...

[Christophe]

Otherwise I advanced the rear floor....100% recovery or falls and as light as possible: 10 mm + 3.6 or 3 * 3.6 mm plywood...it's not very pretty (especially the bottom of the body...which is very ugly! I'm going to put some more PVC to plug the 2 holes in the doors) but hey, it works...with my 85 kg per foot!

La Fontaine design: the reed bends but does not break!

I also put edge seals on the partitions because with each closing it damaged the edges a little...

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On the other hand, the paint (water-based latex) of the rear partitions is already starting to mold, yet it is sold as exterior latex or wet rooms. ...

In short, I'm going to have to pass the multi-material before winter...

The rest and end: plug the last holes, put the locks, paint the floor of the floor (I still have a very old special floor pot) and general paint... I'm going to have to not hang around because the cold temperatures and bad weather are coming!