K

amagatb

a Referenced to sea level pressure and density at 14.696 psia and 59°F analogous to one atmosphere pressure b One amagat is local density divided by density at 14.686 psia and 0°F, 0.002 662slugs/ft3

a Referenced to sea level pressure and density at 14.696 psia and 59°F analogous to one atmosphere pressure b One amagat is local density divided by density at 14.686 psia and 0°F, 0.002 662slugs/ft3

[Builder, 1964]. At 19,350 ft/s (5,898 m/s) the contraction ratio for supersonic through-flow is 32 and for subsonic through-flow is 128. So, as the vehicle accelerates, the supersonic through-flow engine geometry and combustor are almost constant. For the subsonic through-flow engine the combustor height becomes rapidly smaller and more intensely heated. The pressure and temperature are very high for the subsonic through-flow engine, to the point of being impractical to impossible to operate in a flight weight combustor built from known materials.

Given the combustor conditions, the ratio of engine module drag to aircraft drag can be determined from equation set (4.6).

Engine drag

[( A1 ) eng + H

V A0 J air \ A1

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