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I have 2 error .Error using interp1>re​shapeAndSo​rtXandV (line 445) X and V must be of the same length. Error in interp1 (line 128) [X,V,orig_size_v] = reshapeAndSortXan

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>> %% Turbine Design Parameters
R = 1; % Turbine Radius
N = 1; % Number of Blades
c = 1; % Chord Length
L = 1; % blade Height
%% Operating Parameters
Vo = 1:1:7; % Free Stream Velocity (m/s)
n=36; % Number of Streamtubes ( 180 / 5 = 36 ) ???
w =1:1:7; % Angular Velocity (rad/s)
Xt = w.*R./Vo; %Tip speed ratio
Ao = 3; % initial angle of attack (rad)
%% CONSTANTS FOR STANDARD AIR CONDITIONS AND SEA LEVEL
kv = 1.4607*(exp(-5)); % Kinematic viscosity at 15oC [m^2/s] ???
rho = 1.225; % air density (Standard density at sea level)[kg/m^3] at sea level ????
%% Process
S = 2*L*R; %Swept area [m^2]
theta = -90;
theta2 = -89;
st = 1;
thetau = zeros(1, n); % initialize the arrays
thetad = zeros(1, n);
for st = 1:1:36
if theta < 0
theta = theta + 360;
end
if theta2 < 0
theta2 = theta2 + 360;
end
if theta - 360 < 0 % ?????
theta = theta - 360 + (179 / 36) ;
else
theta = theta + (179 / 36);
end
if theta2 - 360 < 0
theta2 = theta2 - 360 - (179 / 36);
else
theta2 = theta2 - (179 / 36);
end
thetau(st) = theta * pi / 180;
thetad(st) = (theta2) * pi / 180;
end
Vu = Vo;
%%---------------UPSTREAM CALCULATION---------------------
i = 0; %initialize the counter value
while (i~=n)
i = i+1;
% Wu=local resultant air velocity
Wu = sqrt( Vu.^(2).*( (Xt - sin ( thetau(i))).^(2) + (cos ( thetau(i))).^(2)));
Reb = Wu*c/kv; %Local Blade Reynolds number
%% Airfoil
% Type of airfoil
typeNACA = '2412';
% Extracrt values from type of airfoil string
Minit = str2double(typeNACA(1));
Pinit = str2double(typeNACA(2));
Tinit = str2double(typeNACA(3:4));
% Actual percentage values of airfoil properties
M = Minit/100;
P = Pinit/100;
T = Tinit/100;
%%
%if NACA == 15
%[A1, Cl1, Cd1] = NACAfinder15(Reb);
%else
%[A1, Cl1, Cd1] = NACAfinder21(Reb);
%end
A1=0:5:180;
cd1=1:1:35;
cl1=2:1:37;
costh = cos(thetau(i));
cosao = cos(Ao);
sinth = sin(thetau(i));
sinao = sin(Ao);
A =asin(costh.*cosao-(Xt-sinth).*sinao / sqrt((Xt-sinth).^2+(costh.^2)));
Cd = interp1(A1,cd1,A,'linear');
Cl = interp1(A1,cd1,A,'linear');
switch true
case 0<A && A<60
Cd = 0.5;
Cl = 0.5;
case 60<=A && A<140
Cd = (200 - 2 * Ao) / 80;
Cl = (200 - 2 * Ao) / 80;
case 140<=A && A<160
Cd = (A - 173.33) / 26.66;
Cl = (A - 173.33) / 26.66;
case 160<=A && A<180
Cd = (A - 180) / 80;
Cl = (A - 180) / 80;
end
au = 1.01; % velocity induction factor upstream
newau = 1; % initialize, au must be different from newau ??????
while (au-newau)>(10^(-3))
Vu = Vo*(au); %Vu =velocity upstream of wind turb
X = R*w/Vu; %Local Tip speed ratio
if ((A) < 0)
A = -1 * A;
Cl = -1 * Cl;
end
% Wu=local resultant air velocity
Wu = sqrt( Vu^(2)*( (X - sin ( thetau(i)))^(2) + (cos ( thetau(i)))^(2)));
% interp1 is 1-D data interpolation for example x goes 1 to 5 , y has 6
% point and also you can define 18 points on that figure, those 6 points
% are main points for your graph but also the other 18 points are wanted to
% show on that figure.
%% Continue
% Cn = normal coefficient, % Ct = tangential coefficient
Cnu = Cl*cosd (A) + Cd*sind (A); %note that A is in degrees
Ctu = Cl*sind (A) - Cd*cosd (A);
% fup = function to find interference factor (au)
g=@(thetau) (abs(sec (thetau)).*(Cnu.*cos(thetau) - thetau) - Ctu.*sin(thetau)).*(Wu./Vu).^2;
for g = 0:10
fup(g) = ((Abs(1 / ((Cos((-pi / 2) + (g * pi /10)))))) * (cnu * Cos((-pi / 2) + (g * pi / 10)) - ctu * Sin((-pi / 2)+ (g * pi / 10))));
actfup = (N * c* y / (8 * pi * R ))* ((pi / 30) * ((fup(0) + fup(10)) + (4 * (fup(1) + fup(3) + fup(5) + fup(7) + fup(9))) + 2 * (fup(2) + fup(4) + fup(6) + fup(8))));
end
newau = pi/(actfup+pi); % new interference factor value for the next iteration process
Fnu = (c*L/S)*Cnu*(Wu/Vo)^2; % normal force coefficient
Ftu = (c*L/S)*Ctu*(Wu/Vo)^2; % tangential force coefficient
Tup(i) = 0.5*rho*c*R*L*Ctu*(Wu^2);
av_tup_i = (1 / 3) * ((Tup(1) + Tup(36)) + 4 * (Tup(3) + Tup(5) + Tup(7) + Tup(9) + Tup(11) + Tup(13) + Tup(15) + Tup(17) + Tup(19) + Tup(21) + Tup(23) + Tup(25) + Tup(27) + Tup(29) + Tup(31) + Tup(33) + Tup(35)) + 2 * (Tup(2) + Tup(4) + Tup(6) + Tup(8) + Tup(10) + Tup(12) + Tup(14) + Tup(16) + Tup(18) + Tup(20) + Tup(22) + Tup(24) + Tup(26) + Tup(28) + Tup(30) + Tup(32) + Tup(34)));
av_Tup = N*(av_tup_i)/(2*pi); % up stream average torque
av_Cqu = av_Tup/(0.5*rho*S*R*Vo^2);
Cpu = av_Cqu*Xt; % Upstream power coefficient
Auvector (i) = A; % Store angle of attack value
auvector (i) = newau; % Store au value in a vector
end
%%---------------DOWNSTREAM CALCULATION---------------------
j = n+1;
flag =0;
i = 0; %initialize the counter
while (j~=1)
j = j-1;
i = i+1; % interference factor downstream.
ad = 1.01; % velocity induction factor upstream
newad = auvector(j); % initialize, au must be different from newau
while (ad-newad)> 0.001 %Iterative process to find ad
ad = newad;
Ve = Vo*((2*auvector(j))-1); %Ve = air velocity inside cylinder
Vd = Ve*ad;
if vd > 0
X = r * w / vd;
else
X = ve * 1.01;
end
Wd = sqrt ( Vd^2*( (X -sin (thetad(i)))^2 + (cos (thetad(i)))^2));
Reb = Wd*c/kv;
if NACA == 15
[A1, Cl1, Cd1] = NACAfinder15(Reb);
else
[A1, Cl1, Cd1] = NACAfinder21(Reb);
end
costh = cos(thetad(i));
cosao = cos(Ao);
sinth = sin(thetad(i));
sinao = sin(Ao);
A2 = asin((costh*cosao -(X-sinth)*sinao)/sqrt((X-sinth)^2+(costh^2)));
neg = 0;
if ((A2) < 0)
neg = 1
end
A2 = abs(A2*180/pi);
Cl = interp1 (A1, Cl1, A, 'linear');
Cd = interp1 (A1, Cd1, A, 'linear');
switch A2
case 0<A && A<60
cd = 0.5;
Cl = 0.5;
case 60<A && A<140
cd = (200 - 2 * Ao) / 80;
Cl = (200 - 2 * Ao) / 80;
case 140<A && A<160
cd = (Ao - 173.33) / 26.66;
Cl = (Ao - 173.33) / 26.66;
case 160<A && A<180
cd = (Ao - 180) / 80;
Cl = (Ao - 180) / 80;
end
if (neg==1)
A2 = -1*A2;
Cl =-1*Cl;
Cd =1*Cd;
end
Cnd = Cl*cosd (A2) + Cd*sind (A2);
Ctd = Cl*sind (A2) - Cd*cosd (A2);
g=@(thetad) (abs(sec (thetad)).*(Cnd.*cos(thetad) - Ctd.*sin(thetad)).*(Wd./Vd).^2);
for g1 = 0 : 10
y = integral (@g, 91*pi/180, 269*pi/180);
fdw(g1) = ((abs(1 / (cos((-pi / 2) + (g1 * pi / 10))) ^ (-1))) * (Cnu * cos((-pi / 2) + (g1 * pi / 10)) - Ctu * sin((-pi / 2) + (g1 * pi / 10))));
actfdw = (N * c * y / (8 * pi * r)) * ((pi / 30) * ((fdw(0) + fdw(10)) + (4 * (fdw(1) + fdw(3) + fdw(5) + fdw(7)+ fdw(9))) + 2 * (fdw(2) + fdw(4) + fdw(6) + fdw(8))));
end
if (flag ==0)
newad = pi/(fdw+pi);
end
if (newad<0.01)
warning('newad< 0.01 at theta = %d and A = %d', (thetad(i)*180/pi), A);
if (i>1)
newad = advector(i-1);
else
newad = auvector (i);
end
flag = 1;
end
end
Advector (i) = A;
advector (i) = newad;
Fnd (i) = (c*L/S)*Cnd*(Wd/Vo)^2; % normal force coefficient
Ftd (i) = (c*L/S)*Ctd*(Wd/Vo)^2; % tangential force coefficient
Tdw (i) = 0.5*rho*c*R*L*Ctd*Wd^2;
end
end
% Average upstream torque
ts4 = f_trapezoidal_integration_s (thetad, Tdw);
av_Tdw = N*(ts4)/(2*pi); % upstream average torque age torque
% Average torque coefficient
av_Cqd = av_Tdw/(0.5*rho*S*R*Vo^2);
Cpd = av_Cqd*Xt; % downstream power coefficient
Cpt = Cpd+Cpu; % Total power coefficient
av_T = av_Tup + av_Tdw; % Total average torque [Nm]
Error using interp1>reshapeAndSortXandV (line 445)
X and V must be of the same length.
Error in interp1 (line 128)
[X,V,orig_size_v] = reshapeAndSortXandV(X,V);

Answers (1)

Askic V
Askic V on 16 May 2023
Please have a look at the documentation for the information how to use interp1 function correctly:
You're geeting this error because of this:
A1=0:5:180;
size(A1) % check dimensions
cd1=1:1:35;
size(cd1) % check dimensions
As you can see, A1 has 37 points and cd1 only 35. That is why interp1 is complaining and telling you that A1 (X) and cd1 (V) must be of the same length.

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