Chapter 7: Introduction to Drag Flashcards
1
Q
Total Drag Components
A
Total Drag = Parasite + Life Induced
Parasite = Form + Skin + Interferance
Form + Skin = Profile Drag
2
Q
Drag Coefficient
A
D per surfance and dynamic pressure
3
Q
Boundary Layer
A
Viscous layer up to 99% of stream velocity
4
Q
Laminar vs. Turbulent
A
Laminar:
thin, slippery, low energy, low skin friction, moves parallel to surface
Turbulent:
thick, draggy, high energy, high skin friction, moves many directions
5
Q
Reynolds Number
Laminar and Turbulent on Wing
A
Re = Lc/visc == inertial /viscous forces
Re < .5 M -> laminar (viscous)
Re > .5 M -> turbulent (inertial)
Near LE - laminar (never past max t)
6
Q
Adverse Pressure Gradient
A
Flow from high to low at trailing edge
