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Y-foil at -3, 0, 5, 10 degrees

T-foil at -3, 0, 5, 10 degrees

Canard at 2, 3, 4, 5, 7, 14m/s

given 750N lift on rear foil

Y foil:

at 12 knots, reynolds number 6 x 10^5 from this calculator, using viscosity = 0.89cP, D=0.09m, p=1000kg/m^3, v =6m/s

at -3 degrees, cl=0.1, cd=0.01

Lift force=L=C_L x A x ½rV²

projected area = 0.076m^3

L=750 = 0.1 x 0.076 x 0.5 x 1000 x V x V

=> V=14m/s

C_di =   (C_L^2) /  p e AR = 0.1^2/3/6=0.0006

Cdtotal = 0.01

drag force=D = C_Dtotal x A x ½rV²

Area=0.55 x 2 x (0.09+0.067)/2 = 0.086m^2

p=1000kg/m^3

V=14m/s

D=0.01 x 0.086 x 0.5 x 1000 x 14 x 14 = 76N

at 0 degrees, cl=0.4, cd=0.01

L=750 = 0.4 x 0.076 x 0.5 x 1000 x V x V

=> V=7m/s

C_di = 0.4^2/3/6=0.008

Cdtotal = 0.018

D=0.018 x 0.086 x 0.5 x 1000 x 7 x 7 = 38N

at 5 degrees, cl=0.85, cd=0.01

L=750=0.85 x 0.076 x 0.5 x 1000 x V x V

=>V=4.8m/s

C_di =   0.85^2/3/6=0.04

cdtotal=0.05

D=0.04 x 0.086 x 0.5 x 1000 x 4.8 x 4.8 =40N

at 10 degrees, cl=1.3, cd=0.02

L=750=1.3 x 0.076 x 0.5 x 1000 x V x V

=>V=3.9m/s

C_di =  1.3^2/3/6=0.09

cdtotal=0.11

D=0.11 x 0.086 x 0.5 x 1000 x 3.9 x 3.9 = 72N

T foil:

at 12 knots, reynolds number 9 x 10^5 from this calculator, using viscosity = 0.89cP, D=0.13m, p=1000kg/m^3, v =6m/s

at -3 degrees, cl=0.1, cd=0.01

projected area = 0.072m^3

L=750=0.4 x 0.072 x 0.5 x 1000 x V x V

=>V=14.4m/s

C_di =  0.1^2/3/2=0.0015

cdtotal=0.012

Area=0.072

D=0.012 x 0.072 x 0.5 x 1000 x 14.4  x 14.4 = 90N

at 0 degrees, cl=0.4, cd=0.01

L=750=0.4 x 0.072 x 0.5 x 1000 x V x V

=>V=7.2m/s

C_di =  0.4^2/3/2=0.024

cdtotal=0.034

D=0.034 x 0.072 x 0.5 x 1000 x 7.2  x 7.2 = 63N

at 5 degrees, cl=0.85, cd=0.01

L=750=0.85 x 0.072 x 0.5 x 1000 x V x V

=>V=5m/s

C_di =  0.85^2/3/2=0.12

cdtotal=0.13

D=0.13 x 0.072 x 0.5 x 1000 x 5 x 5 = 117

at 10 degrees, cl=1.3, cd=0.025

L=750=1.3 x 0.072 x 0.5 x 1000 x V x V

=>V=4m/s

C_di =  1.3^2/3/2=0.27

cdtotal=0.3

D=0.27 x 0.072 x 0.5 x 1000 x 4 x 4 = 150N

Canard

given a lift of 250N

angle of attack fixed at 15degrees

max area=0.031m^2

pre-takeoff a circular strut (28mm DIA, 380mm long) is also immersed

at 2m/s,

 cl= 2 x p x AOA = 2 x 3 x 15/59 = 1.5

L=250=1.5 x Area x 0.5 x 1000 x 2 x2

Area = 0.08m^2 (too much, takeoff not possible)

Cd=1.28sin(AOA)+(C_L^2) /  p e AR=1.28 x sin(15) + (1.5^2)/3/0.7=1.4

Cd of strut = 1.3

D=1.4 x 0.03 x 0.5 x 1000 x 2 x 2 = 84N (of plate)

D=1.3 x 0.028 x 0.38 x 0.5 x 1000 x 2 x 2 = 28N (strut)

at 3m/s,

L=250=1.5 x Area x 0.5 x 1000 x 3 x 3

Area = 0.03m^2 (takeoff just possible)

D=1.4 x 0.03 x 0.5 x 1000 x 3 x 3 = 189N (of plate)

D=1.3 x 0.028 x 0.38 x 0.5 x 1000 x 3 x 3 = 63N (strut)

at 4m/s

L=250=1.5 x Area x 0.5 x 1000 x 4 x 4

Area = 0.02m^2

D=1.4 x 0.02 x 0.5 x 1000 x 4 x 4 = 224N (plate)

at 5 m/s

L=250=1.5 x Area x 0.5 x 1000 x 5 x 5

Area = 0.013m^2 (higher aspect ratio)

drag coefficient drops to 1.2

D=1.2 x 0.013 x 0.5 x 1000 x 5 x 5 = 195N (plate)

at 7m/s

L=250=1.5 x Area x 0.5 x 1000 x 7 x 7

Area = 0.007m^2 (much higher aspect ratio)

drag coefficient drops to 0.8

D=0.8 x 0.003 x 0.5 x 1000 x 7 x 7 = 59N (plate)

at 14m/s

L=250=1.5 x Area x 0.5 x 1000 x 14 x 14

Area = 0.001m^2 (very higher aspect ratio)

drag coefficient drops to 0.4

D=0.4 x 0.003 x 0.5 x 1000 x 14 x 14 = 120N (plate

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