Hi Pete,
Quote:
Originally Posted by Ironside
The conduit I mention is exactly as you describe, I'd prefer to go with a stick on chrome strip (easier and better looking), with a double sided sticky foam tape underneath so that it stands 5 or 6 mm proud of the surface.
I don't know the minimum effective thickness or best cross section shape of the stall strip, so this is the plan :-
1. Make some tufts (Chapter 25 as you said) and stick them down one side.
2. Tape down a piece of rope along the centre line (I have 7mm rope laying around).
3. Rig up a large extractor fan to mimic the wind from different directions and at various angles of lean.
4. Post the video here so that people with more knowlege than me can analyse the results, and hopefully advise accordingly.
Any suggestions before I start?
Pete.
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Your plan is as good as far as I'm concerned.
The height of stall strips is something best determined experimentally as no one here is a PHD brainiac aerodynamicists with years of wind tunnel use (I'm sure someone will falsely claim such curriculum vitae). Just plan on a few experiments with various shapes and sizes. Tuft pictures of the experiments might show something obvious.
Edit: For your tests at various angles, remember the vector sum of a side wind and forward velocity. Tony Foale
Tony Foale Designs, article on motorcycle aerodynamics. gives an example of a 15 mph side wind and 75 mph forward speed results in an apparent wind of 76.5 mph at 10 degrees to the over the road direction. I don't expect your fan has such power to make a 76.5 mph wind but the angle is a good start. The idea is to study how your stall strips ruin the airflow on the down wind side and presumeably the unwanted lateral lift. The tufts should indicate turbulent flow at the body surface. Some one has pointed out tuft testing isn't the whole picture but it's a start. Smoke generators are more problematic although possible for some one with excellent shop facilites.
THEN ... road test! As Visionary asked, how do you quantify the results? I don't have an answer at this time. Your best impression is about as good as any opinion on this forum.
Regards,
Teri