Question

Determine the initial estimation of parasite drag coefficient if, equivalent skin friction coefficient is 0.004 and ratio of wetted area to the reference area is 0.8.

(a) 0.0032

(b) 1.2

(c) 4.2

(d) 0.04

The question was asked in an international level competition.

My question is taken from Aerodynamics topic in chapter Aerodynamics of Aircraft Design

Answer 1

Right option is (a) 0.0032

The best explanation: Parasite drag coefficient = equivalent skin friction coefficient*area ratio

= 0.004*0.8 = 0.0032.