Thread: Considerate B-Doubles?

Originally Posted by vnx205

Ah! So it is partly self preservation or to avoid having to scrape bits of caravan off the side of their truck.

While the Benoulli effect didn't seem very strong when trucks passed me, perhaps because of the size of the gap between us, I noticed it quite a bit a few times when they overtook me.

It is slightly disconcerting catching the sight of a huge truck tyre beside your window and having your vehicle move a bit closer. It is only slightly unnerving in a tall, relatively heavy vehicle like the Defender. I imagine it would be much more alarming in a very light, low convertible where the truck tyre towers over you.

I would be more concerned about the useless ***** that overtake me on the crest of a hill or at a blind corner than I am about a truck overtaking me in a perfectly safe manner.
The only trucks I get concerned about here are the farmer operators taking their grain to the silo or taking fertiliser back to the farm.

The suck effect is primarily noticed at the front and at the back, but being between these isnt plain sailing either, with buffeting common.

The biggest suck effect i have noticed is between two tautliner bdoubles driving next to each other at similar speeds. You can get large swings, you want to be poised for immediate steering correction.

Linfox were/are running trucks like this with very short wheelbase, single axle prime movers, for light loads. They are unsafe combinations, swinging all over the place from suck effects.

A truckie once parked his log truck on the side of the highway, which had a fair bit of camber, while he went across the road for some dinner. A tautliner drove past and the log truck ended up on its side.

Originally Posted by vnx205

Ah! So it is partly self preservation or to avoid having to scrape bits of caravan off the side of their truck.

While the Benoulli effect didn't seem very strong when trucks passed me, perhaps because of the size of the gap between us, I noticed it quite a bit a few times when they overtook me.

It is slightly disconcerting catching the sight of a huge truck tyre beside your window and having your vehicle move a bit closer. It is only slightly unnerving in a tall, relatively heavy vehicle like the Defender. I imagine it would be much more alarming in a very light, low convertible where the truck tyre towers over you.

Do you mean Bernoulli?

Not really applicable to a compressible gas.

Originally Posted by Tombie

Do you mean Bernoulli?

Not really applicable to a compressible gas.

Yes Bernoulli.

I thought it did apply to compressible gas because a common example of its effect is the lift created on an aeroplane wing by the increased velocity of the air flowing over the top.

EDIT: It seems we may both be correct (up to a point).

I think the original formula applied to incompressible fluids, but the same effect occurs with compressible fluids, and the formual used to calculate it is different. But it is still descibed as the Bernoulli Effect.

Howver, it certainly is Bernoulli, not Benoulli. You were right about that.