`%Number of Blades`

B = 3; %Relative Velocity

U = 10; %m/s

rho = 1.2754; % kg/m^3

a = (1/3); ar = (1-3*a)/(4*a-1);om = 11/60; %rps

%Wind Velocity at the rotor

Vw = U*(1-a);%% Read csv files

filename = 'DBAeroprop.csv'filename2 = 'AirfoilData.csv'A = readtable(filename);A.Properties.VariableNames = {'Node' 'RNodes' 'AeroTwst' 'DRNodes' 'Chord'};B = readtable(filename2);B.Properties.VariableNames = {'Angle' 'Cl' 'Cd'}%% Finding Torque

dr = 1;r = [0:dr:100];Q=0; %initialization

for i=1:length(r)% velocity

v = om*2*pi*r(i);% Circuferential velocity

Vr = v*r(i)*(1+ar);% chord

c = interp1(A.RNodes, A.Chord, r(i));% phi angle

phi = atan((U*(1-a)) / (v*r(i)*(1+ar)));% Twist angle

theta = interp1(A.RNodes, A.AeroTwst, r(i));% Angle of attack

alpha = phi - theta;% Cl and Cd (start assuming Cl and Cd fixed then you have to find the way to define Cl and Cd as function of alpha using the tables)

Cl = find_cl(alpha); Cd = find_cd(alpha);% Relative velocity

Ur = sqrt(Vr^2 + Vw^2);% Torque

dQ = B*(1/2)*rho*Ur^2*(Cl*sin(phi)-Cd*cos(phi))*c(i)*r(i)*dr; Q = Q+dQ;end%% Finding Cd and Cl based on the angle alpha

function Cl = find_cl(x) Cl = interp1(B.Angle, B.Cl, x)end function Cd = find_cd(x) Cd = interp1(B.Angle, B.Cd, x)end

I believe I am either misusing the interpolation function or have something confused when utilizing it in a for loop. My error reads:

Unable to resolve the name B.Angle.

Error in BET_review>find_cl (line 56)

Cl = interp1(B.Angle, B.Cl, x)

Error in BET_review (line 45)

Cl = find_cl(alpha);

But I don't see any utilization of the interpolation function working. Any help appreciated. Thanks!

## Best Answer