Estimating Zero-lift Drag
As noted earlier, .
The total drag coefficient can be estimated as:
- ,
where is the propulsive efficiency, P is engine power in horsepower, sea-level air density in slugs/cubic foot, is the atmospheric density ratio for an altitude other than sea level, S is the aircraft's wing area in square feet, and V is the aircraft's speed in miles per hour. Substituting 0.002378 for, the equation is simplified to:
- .
The induced drag coefficient can be estimated as:
- ,
where is the lift coefficient, A is the aspect ratio, and is the aircraft's efficiency factor.
Substituting for gives:
- ,
where W/S is the wing loading in lb/ft².
Read more about this topic: Zero-lift Drag Coefficient
Famous quotes containing the words estimating and/or drag:
“I am sure that in estimating every man’s value either in private or public life, a pure integrity is the quality we take first into calculation, and that learning and talents are only the second.”
—Thomas Jefferson (1743–1826)
“Our own theological Church, as we know, has scorned and vilified the body till it has seemed almost a reproach and a shame to have one, yet at the same time has credited it with power to drag the soul to perdition.”
—Eliza Farnham (1815–1864)