Key equations and terms

Question 1

Relationship between VT and VE

Answer 1

Vtas^2rho=Veas^2rho0

Question 2

Best Cl

Answer 2

sqrt(cdo/K)

Question 3

Taper ratio equation

Answer 3

3/2 Cr (y+1)/(y^2 +y + 1)

Question 4

How to stop divergance?

Answer 4

Less aerofoil slope, reduce b, reduce c, move spans to increase 2nd polar moment of area, stiffness, ac and elastic axis closer

Question 5

Volume box equation

Answer 5

dftcr

Question 6

Thurst equation

Answer 6

= mdot(ve-vi)+(pe-pi)Ae

Question 7

thurst and power equation

Answer 7

T=(p*efficiency)/v

Question 8

Changing power at altitude

Answer 8

Pslpalt^2=Paltpsl^2

Question 9

wing - > aerofoil coefficents

Answer 9

/0.95 /0.9

Question 10

typical values for taper ratio and twist

Answer 10

0.3 -1.5 degrees

Question 11

Piston engine, propellor or jet?

Answer 11

propellor

Question 12

Vtip static ^2

Answer 12

vtip^2-Vc^2

Question 13

w

Answer 13

vtipstatic*2 / Df

Question 14

w -> N

Answer 14

60/ (2*pi)

Question 15

Best L/D

Answer 15

tangential intersection from (0,0)

Question 16

What unit should dCl/da be in?

Answer 16

radians

Question 17

Why do we calculate load factor

Answer 17

To measure the severity of an manoeuvrer

Question 18

What is the equation for load factor

Answer 18

L/W

Question 19

Is an Electric engine prop or jet

Answer 19

prop

Question 20

What is the disadvantages of electric engines

Answer 20

Batteries add weight and limited duration

Question 21

disadvantage of parasole wing

Answer 21

adds additional weight

Question 22

disadvantage of mid wing

Answer 22

has to cut through fuselage

Question 23

disadvantage of low wing

Answer 23

gets heat and disturbed air of the runway but ground effect means its easier to take off.

Question 24

Lowest drag wing combination

Answer 24

medium wing

Question 25

Where do we want the aircraft gravity centre to be

Answer 25

close to the wing

Question 26

Why is elliptic lift distribution what everyone aims for

Answer 26

Least drag for given span

Question 27

aerofoil of tail needs to be [2]

Answer 27

symmetrical, less thick then wing

Question 28

pusher engine why?

Answer 28

wings have clean air but then engine doesnt

Question 29

puller

Answer 29

engine has clean air but then wings don't

Question 30

centripetal force

Answer 30

m v^2 / r

Question 31

what is a spoiler

Answer 31

used in landing for reducing lift (secondary control decide)

Question 32

in steady pull up, circular acceleration acts inwards or outwards

Answer 32

outwards

Question 33

Breguet range eq

Answer 33

-V/c *L/D*ln(Wf/Wi)

Question 34

linear matching plot equations

Answer 34

jet take off prop maximum speed

Question 35

disadvantage of having more wings

Answer 35

more interference/ vortices

Question 36

how to pick setting angle

Answer 36

the angle of attack at the cl ideal

Question 37

what do you want cm to be

Answer 37

as low as possible

Question 38

cli what

Answer 38

minum drag

Question 39

dihedral what

Answer 39

improve stability

Question 40

anhedral

Answer 40

improves roll manvourvability, especailly when its stable

Question 41

how to you choose aerofoil

Answer 41

max lift coefficent for point but doesnt matter if its less

Question 42

for lifting line theory what two things need to be true for it to be passable

Answer 42

Cl needs to be more than required and shape of graph need to be alliptal- highest point in the middle

Question 43

cr and ct

Answer 43

ct=y*cr

Question 44

ramjet

Answer 44

SuperJet engine, have to use it when its already going

Question 45

under wing location what

Answer 45

clean air, decrease bending stresses, get debris going in the runway

Question 46

why more engines

Answer 46

safer

Question 47

why t tail

Answer 47

out of the flow at stall

Question 48

why twin vertical tail

Answer 48

high directional controls

Question 49

what is a Cruciform Tail

Answer 49

in the middle between t and convention

Question 50

what are the two types of static aeroelastity

Answer 50

divergence and control surfaces reversal

Question 51

what is the only type of dynamic aeroeleastity

Answer 51

flutter

Question 52

What causes flutter

Answer 52

resonance speed of wind