back where we were less filling [smiley=1-boxing2.gif] tastes great [smiley=smashfreakB.gif] To the airplane wing, it doesn't matter if the wing is moving thru the air or the plane is sitting on the ground in 500 mph wind. The airfoil on the wing creates lift. How? The air travels at 2 different speeds. The slower air goes under the wing, less distance to travel. The air that goes over the top of the wing is accelerated because it has to travel a further distance in the same time period. This faster air has now dropped in pressure. So the higher pressure section that is under the wing can direct itself towards the lower pressure on top of the wing and give it lift. And yes the molecules next to the wing are moving. An extreme example is the sr-71 blackbird. That plane was designed to take into account the friction of that plane flying so fast. On the ground it drips fuel like a leaky faucet and has to be refueled as soon as it is airborne. Then it hauls assssszzzzzzzzzzzzzzzzzzzzzzzzzzz and heats up and the body panels expand to seal itself. What you are calling form drag is basicallt what causes eddy currents as a fluid moves by a stationery object or an object moves thru a fluid. Off the top of my head if I can remember, wind coming around a building or a tree takes 10times the height of the object in distance downstream of the object to straighten back out into a smooth or close to a laminar type flow. I can't remember the water and piling example I learned. But look at a dock post in the current and see long it takes for the water to straighten out. The ship's bow bulkhead does what you explained "So by mixing the layers of flow together it helps speed up the molecules closer to the hull and they dont get "left behind" this gets the water moving around the hull of the ship to cut down on drag. This is done on just about all ships in over to increase effiecency and save on fuel costs. The shark's skin is the perfect example and they have been around since the beginning of time with very little evolution. Which now the olympic swimmers have somewhat tried to duplicate and broken just about every swimming record there is in a short span of time since the introduction of thesesuits. Basically fine sand bar type surface that breaks that laminar flow barrier and makes the water next their bodies turbulent and reduces friction allowing them to cut thru the water faster. What's a remolds number? Do you mean reynolds number?