Thermodynamics and Propulsion | |

## 13.1 Vehicle DragRecall from fluids that drag takes the form shown in Figure 13.2, being composed of a part termed parasitic drag that increases with the square of the flight velocity, and a part called induced drag, or drag due to lift, that decreases in proportion to the inverse of the flight velocity.
where and Thus
The minimum drag is a condition of interest. We can see that for a given weight, it occurs at the condition of maximum lift-to-drag ratio, We can find a relationship for the maximum lift-to-drag ratio by setting from which we find that and and UnifiedTP |