Some more stuff on lift which we are all concerned with 
Theories Of Lift - Aviation Safety (aviationsafetymagazine.com)
Theories Of Lift - Aviation Safety (aviationsafetymagazine.com)
Interesting Article on Lift
- Thread starter kloudie1
- Start date
well errrr uhhhhh where to start.
1) Newtons LAWs are named Laws because they are proven.
2) Bernoulli is NOT a Law
The standard short version of Bernoulli is can not be used on Lift Calculations.
You must Start with an overall "Conservation of Energy Balance" and Bernoulli canceled out most terms to simplify for
Fluid Dynamics
Just because they have not defined the "Micro Model" science does not stop Air Foil design.
Please note that Weather Forecasting uses the same science.
Jim...
1) Newtons LAWs are named Laws because they are proven.
2) Bernoulli is NOT a Law
The standard short version of Bernoulli is can not be used on Lift Calculations.
You must Start with an overall "Conservation of Energy Balance" and Bernoulli canceled out most terms to simplify for
Fluid Dynamics
Just because they have not defined the "Micro Model" science does not stop Air Foil design.
Please note that Weather Forecasting uses the same science.
Jim...
My brain's exploding.
After 50 years of sailing and flying, I just know it works... thankfully!
After 50 years of sailing and flying, I just know it works... thankfully!
I recommend “What Makes Airplanes Fly?: History, Science, and Applications of Aerodynamics” by Peter P. Wegener, my tutor, mentor in fluid mechanics, and friend.
He was one of the top fluid mechanics experts of the last century, and worked hard at expaining flight and other topics to folks with a minimum of math.
He was one of the top fluid mechanics experts of the last century, and worked hard at expaining flight and other topics to folks with a minimum of math.
I have always visualized lift as millions of molecules of air bouncing off the sails like billiard balls, being sucked around the leeward side, and bouncing and pushing on each other in the form of pressure. The net redirection of momentum causing forward force (and sideways of course, and aft when I screw things up).
If you need a law to simplify, the force is always perpendicular to the surface of the sail (this isn't actually true, but a simplification).
If you need a law to simplify, the force is always perpendicular to the surface of the sail (this isn't actually true, but a simplification).
Fairly close to what is happening in Fluid Dynamics.
A bit complicated math, but look at the graphics in this link.
Stream Lines
Jim...
In my opinion and experience (engineer) there are three ways of looking at fluid dynamics:
- Measure it, either in a test tank or on the water, with a lot of instrumentation.
- Complex theories, which include momentum and friction.
- A few rules of thumb, tell tales, and wind indicators, combined with what my seat is telling me about the motion, and what my eyes are telling me about my progress compared to other boats.
I really enjoy reading and thinking about the physics and mechanics of what makes a boat go. But when I’m on the water I don’t find any of that to be nearly as actionable as just observing and feeling the effects of trimming the sails.
When I take a newb out for the first time… I like to use the analogy of an airplane but in the case of the boat, one of the wings (the keel) is in the water and the other (the sail) is in the air. Since the water is denser than air, the “water wing” does not need to be as large as the wind wing. Anyway, you see where I’m going with this…
How a sail and keel works | Freedom Sailing Scotland
How a sail and keel works In the golden age of sail, large square riggers struggled to sail towards the wind and mostly sailed or were blown downwind by the trade-winds. Sail and rig design has evolved considerably and designers now have a better understanding of aerodynamics with associated...
freedomsailingscotland.com
half the science is the vessel, the other half is knowing how the air crosses the surface of the earth. then the interplay between the two. oh, it's a fun game we play.
want the rule book?
buy this.
it covers all the above yawl are talking about.
want the rule book?
buy this.
it covers all the above yawl are talking about.
NotCook
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- Dec 29, 2008
- 806
I can relate to that. As first a sailplane pilot, then a powered pilot, then a sailor, and then a skydiver, I think the feel is what you learn to use (of course in instrument flying conditions, the feel will get you killed). You develop that feel, and make adjustments. You know you are going faster before you confirm it by looking at the instruments.
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