Aerospace Engineering

Question 1

“When you are speaking to technically illiterate people you must repost to the Plausible Falsehood instead of the Difficult Truth”

Answer 1

Dr. Theodore Von Karman

Question 2

continuity equation

Answer 2

ρ1 * A1 * V1 = ρ2 * A2 * V2

Question 3

compressible flow

Answer 3

flow in which the density of the fluid elements can change from point to point ρ1≠ ρ2
applies when high speed of air (v>100m/s)

Question 4

incompressible flow

Answer 4

flow in which the density of the fluid elements is always constant

Question 5

continuity equation

Answer 5

relates properties between different points along a streamtube ρ1 * A1 * V1 = ρ2 * A2 * V2

Question 6

incompressible flow

Answer 6

flow in which the density of the fluid elements is always constant ρ1=ρ2

Question 7

streamtube

Answer 7

same principle as stream line, but unlike the streamline, the stream tube has a area
when two points are connected through a stream tube, continuity equation applies
ρ1 * A1 * V1 = ρ2 * A2 * V2

Question 8

shear stress

Answer 8

shear stress is applied tangential to surface (friction)

Question 9

Bernoully equation

only valid for frictionless incompressible flow

Answer 9

relates properties between different points along a streamline ( no area)

only valid for frictionless incompressible flow
p1 + 0.5 * ρ * v1 ^2 = p2 + 0.5 * ρ * v2 ^2

pressure 1 + 0.5 times density of fluid times the velocity squared = pressure two + 0.5 times density of fluid times the velocity of fluid squared

Question 10

Bernoully equation

Answer 10

only valid for frictionless incompressible flow
p1 + 0.5 * ρ * v1 ^2 = p2 + 0.5 * ρ * v2 ^2

pressure 1 + 0.5 times density of fluid times the velocity squared = pressure two + 0.5 times density of fluid times the velocity of fluid squared

Question 11

lift

Answer 11

low pressure at upper streamline high pressure at lower streamline => lift