Thread: Drag Coefficient

The Discovery 4 is about Cd 4, a Defender is about Cd 6, so without putting into a CFD simulator I'm guessing about Cd of 10!

I wonder how much weight is on there as the max is 100KG?

Originally Posted by scarry

I wonder how much weight is on there as the max is 100KG?

...and that could be generous: Discovery 4 Roof Loading

Originally Posted by one_iota

Please guess the Drag Coefficient:

My guess is probably a bit more than a small chook pen but a bit less than a small garden shed.

I should point out the difference between drag coefficient and total drag.

Total drag is the on an object moving through air due to the air flowing past it, and is proportional to the cross section or frontal area of the object and to the drag coefficient, and to the square of the airspeed.

The drag coefficient is the ratio of the drag actually measured for the object relative to a flat plate with the same frontal area at right angles to the airflow.

The examples given above mainly are examples of drag increasing due to increased frontal area rather than changes in the drag coefficient.

Regardless, coefficient, drag, whatever, it would be multiple times better than the Defender and slide on I saw, on the Cunningham this afternoon. It was square and flat on all planes, I could have comfortably stood up in it.
Bet he kept a sharp eye out for low bridges and excessive camber.

[QUOTE=one_iota;3213580]Please guess the Drag Coefficient:

IMG_20240107_155925_DxO.jpg[/QUOT]

As the roof loaded one looks pretty ****ing unsafe to me & I reckon when that goes arse over tit & is dragging along the bitumen the DC will be pretty high & it will quite dangeroos for those riding with it.



What an idjit! Driver "She'll be fine. I don't think the cops will notice anything untoward."

Originally Posted by 4bee

As the roof loaded one looks pretty ****ing unsafe to me & I reckon when that goes arse over tit & is dragging along the bitumen the DC will be pretty high & it will quite dangeroos for those riding with it.



What an idjit! Driver "She'll be fine. I don't think the cops will notice anything untoward."

Jeez thats pretty full on! They look like they're just a couple of surfboards!