Quote:
Originally Posted by cheesehawk
Sorry Doggles, I am sure your formula is off.
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No need to apologize, cheesehawk. The formula I posted is perfectly valid (if a bit simplistic). You'll notice I used the phrases "a crude analysis" and "an approximation". In real life we must also account for components of thrust not in line with the direction of motion, rotation of the fluid within the slipstream, etc. The formula you posted doesn't account for these either. It all depends on how much effort we are willing to invest and how precise we want our approximation to be.
The concept of delta-v added to the flow is not easily discerned from in-cockpit instrumentation. Horsepower on the other hand is at least related to engine RPM, and we have a tachometer in the cockpit
