yvahe

Hi folks.
I'm trying to solve the following problem for my masters thesis: Estimate the drag caused by wind on a free falling body from H altitude. H is in range of 300-1000 meters.
What would be the best way to calculate the drag caused by the wind ?

Assuming I have wind estimates for each altitdue.
Assuming I have drag coefficents of the body for 0.01-0.99 mach numbers.
Assuming I have duartion of the free fall.
Assuming I have center of pressure and center of gravity.

Would be glad for any help.

mgnostic

When you ask about wind, are you talking about the relative wind of the objects trajectory or impact of motion in the surrounding air? The impact of the wind should be a force vector on the object in question. Unfortunately I didn't take any courses in fluid dynamics, so that is about as much as I can point out.

yvahe

The impact of motion of the surrounding air(or the side wind). I believe that it should tlit the object by some little angle(alpha), which will make the total drag H * tan(alpha). However I can't figure out how to calulate that angle. I belive that it should depend on the aerodynamics of the object, especially on the location of center of mass and center of pressure.

mgnostic

Is the object angling into the relative wind to maintain a strait path to a given point or is it following a curve as it is deflected by the side force? If the object is maintaining a straight path then an increase in drag will be relative to whatever deflection of the object is needed maintain that path. If the object is following a curve as it's trajectory is deflected by a side force it's drag shouldn't change because the object isn't deflecting from it's path of least resistance. Unfortunately I don't have the math to describe this. I would suggest a chat with your graduate advisor or thesis advisor. That is what they get paid for. Just be sure to cite every source of info when you write the thesis.