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
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