4 replies to this topic

[mariner]

With camera technology much better nowadays I was thinking about fixing a lot of wool tufts to my sportscar and filming them at speed to get an idea of the real world airflow.

 

Sounds simple and lots of pics of it being done, espeically in windtunnels but how do you actually do it please?

 

How many rows of  tufts are best how long should each tuft be etc.

 

And any ideas on how to fix them on securely without permanent paintwork damage ?

 

Any knowledge, ideas, thoughts are much appreciated

Edited by mariner, 10 September 2014 - 02:05.

[Greg Locock]

about 3-4 inches long, sellotape but no guarantees (an expensive masking tape is a better bet), depends what you are looking for. Windtunnel work involves a surprising amount of suck it and see.

[GreenMachine]

About to do the same thing, for a high mount rear wing. 

 

I am interested in how the airflow is affected behind the rear window, how high the turbulent zone extends above the boot, and how far back.  Also interested in whether there is any downward deflection of the airstream to ensure the AoA is related to airflow, not necessarily the horizontal plane.  Hopefully the wing will be high enough to be in stable airflow ...

[bigleagueslider]

I think threads of a contrasting color to your body would work better. The thin threads would conform better to the thin boundary airflow layer than a thick wool tuft, but the threads would be harder to see in the video. A thread of around 2" long should work OK. You can bond the threads using CA adhesive, but this might leave some residue on your car's paint.

[scolbourne]

You could instead use a smoke generator (frozen CO2 and water ).

 

Attach the output on to your rear wind screen wiper and  record with a video camera maybe.