But the power requirements go up as the cube of the speed

PeterNSteinmetz

Administrator
Staff member
This is from Hall’s book “Where’s My Flying Car?” . So it got me to wondering why is this? The parasitic drag will go like the square of the speed. And then the power is like the drag force times speed?
 
That is pretty much it.

When just plowing through a fluid (no lift) and you want to double the speed you can either use 8 times more power or cut the drag in half. It is typically better to know ways to reduce drag than ways to increase power density, so years ago I spent $75 on a copy of Aerodynamic Drag: Practical Data on Aerodynamic Drag Evaluated and Presented by Sighard F. Hoerner, 1951

Recently discovered the 1965 edition is available for download from archive.org: https://archive.org/details/FluidDynamicDragHoerner1965
 
Back
Top