I'll try and explain.....
Any shaped object moving at any speed through air creates drag and drag is the opposing force of an object moving at speed.
Drag is variable - meaning the negative (suction) air force generated is an unstable, swirling force - called
vortices .
Most of us would have experienced this when you tailgate a truck on the freeway in your car. You enter the unstable air zone (
vortices) behind the truck and it throws your car around a little and you put your foot down to get through it . As you get closer to the rear of the truck the air 'smooths' out and you back off to allow the truck's
drag to pull you along. - from this example you know how unstable and how much force
drag can have just by tailgating a truck in your car.
The use of
vortex generators 'smooths' out
vortices reducing
drag
Reducing /streamlining this negative force is What I'm trying to do.
Calculations - what's needed;
1.finding the
drag coefficient - which is a dimensionless number (quantity) that is used to quantify drag
2. Finding the
Reynolds number - is a number that gives a measure to ratio of a moving solid through air
3. Air Density
4 Lift Coefficient - expressed as a number relating to the lift generated by an aerodynamic body
5. Velocity - speed
6. Surface area
7. Angle of attack - in reference to boats - a horizontal line from bow to stern parallel to the keel
Once all of these are know then they can be applied BUT;
as the
Angle of attack will always be variable in boats (waves, wake, water condition)I used a baseline angle of 5 degrees
Lift Coefficient was reversed as we want downforce and not lift in this case (
Lift Coefficient was not reversed when applied to the Hydro hull design)
downforce can also be calculated on its own if you just want to know the load of something simple like a spoiler or a wing
Then allow 5-6 hours of calculations and there you have it .....
it's not rocket science