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Old 26th Feb 2011, 20:29
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HazelNuts39
 
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Ratio of best RoC speed to Vmd

Originally Posted by BOAC
My dusty brain cell tells me that best R o C is 1.32 Vmd? All to do with the curvy drag/speed graph and power/thrust maths.
Some months ago the question was extensively discussed on another thread. It took me a little while to figure it out, and I finally posted this graph: Ratio of best RoC speed to Vmd . It assumes a parabolic drag polar, and thrust constant with speed. As you can see, the ratio increases with thrust/weight ratio, and is equal to one (1) for the T/W that provides level flight at Vmd. I don't think I should cover the thread with the underlying calculus.

regards,
HN39
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