Thanks Jon
First I read a book about aerodynamics then studied all I could find on the internet. After that I took an aspirin for my head and removed all my fairings .I will run Modified from now on .
These are some of my questions.
I'll give it a shot I just hope Blue doesn't tear me up too bad but I will not mention frontal area!
should the point be at the front ?
"It doesn't much matter how you open the hole, it is all about how you close the hole."
Pork Pie Wendover KOA August '06 (Thanks Sparky!) Except for the Bloodhound SSC!
should the point be at the back?
"It doesn't much matter how you open the hole, it is all about how you close the hole."
Pork Pie Wendover KOA August '06 (Thanks Sparky!)
what are Reynolds numbers?
Osborne Reynolds discovered the parameters that mathematically attempt to describe the changes from laminar to turbulent flows. (Ratio of inertial and viscous [friction] forces.) If you build a 1/4 scale model for a wind tunnel then the speed has to increase by 4X to keep the Reynolds numbers the same. (Similarity Parameters?) Then a 400 mph test has to be at 1600 mph and the air behaves (compresses) quite differently. Now what if we increase the pressure in the wind tunnel?
What is laminar flow?
Classic example is cigarette smoke wisping from the end starts as laminar (parallel layers) and changes to turbulent. Laminar is how everyone (thinks or) would like the "fluid" to go. If we could get the flow in pipes to stay laminar at higher Reynolds numbers it would save huge amounts of energy in pumping fluids. Likewise our taters could go faster with less HP!
why doesn't everyone have golf ball like dents in the fairings?
Because they don't want to spin like a golf ball? Or they do not live in a active, large hailstone area?
what about the sides?
See above!
What is wrong with covering the front wheel?
What if the front fender really acts like a scoop?
how much effect does rider movement have on the coefficient of drag?
If you change your shape (i.e. bigger butt (I DID NOT SAY FRONTAL AREA!)) or change the closing of the air (length & position of big butt) you change the actual shape of the airflow (which never matches the vehicle BTW) and hence the Cd! The Cd is really just for comparing different aero(?) shapes. Refer to Pork Pie quote again!
how does a wind tunnel work? does moving the air at 85 mph then doing math really get the same results on vehicles ment to go 300 mph? Maybe not perzactly, but near enough or so the wind tunnel guys claim!
Why does a 50 caliper bullet have a blunt tail end ?
It's a supersonic thing and it works for 7.62 also! The X-1 was shaped like a 50 cal cause that was considered good at the time and it worked out for Chuck Yeager!
is a tear drop a good aerodynamic shape?
Works great for tears and rain drops!
does paint surface texture make any difference?
Just depends on the texture, boundary layer and Ozzy's numbers. (Google shark skin & riblets!)
does air temperature make any difference?
Temperature changes the air density - all other things equal you can go faster in thinner air.
Wonder if submarines can go faster in lacquer thinner?
even if one of these questions gets answered it would lead to ten more.
Sorry, I couldn't get to ten!
See . That is why I just run Modified. grin.
Buy more aspirin this Subaru never ends! Or make the fairing lots longer like certain green, blue & red machines! And remember this: “... as Sir Cyril Hinshelwood has observed ... fluid dynamicists were divided into hydraulic engineers who observed things that could not be explained and mathematicians who explained things that could not be observed.” - James Lighthill
BTW Rich, even a little red brick sitting on top of a larger red brick with wheels can be improved some!
Enzo Ferrari once said the aerodynamics was for those who can't build engines! But when the HP$$$ run-out then what?
