My integral results are not correct.
2 Ansichten (letzte 30 Tage)
Ältere Kommentare anzeigen
I'm writing a code for the propeller design, but the integral values and results are not coming out as I want. I use this publicition. https://doi.org/10.2514/3.23779.
newzeta_ps needs to be equal to zeta. Also, Tc should be 0.0498.
There are 4 derivative equations in the code.
![](https://www.mathworks.com/matlabcentral/answers/uploaded_files/951399/image.jpeg)
I looked many times but couldn't solve the problem.
clear
clc
V = 49.1744; % [m/s]
epsilon = 0.016789342857143;
zeta = 0.214700101676;
B = 2;
alpha = deg2rad(3.5007);
Cl = 0.7;
rho = 1.225;
D = 1.7526; % [m]
hub = 0.1524; % [m]
R = D/2; % [m]
r = linspace(hub, R, 7);
PropRPM = 2400;
i = 1;
PropRPS = PropRPM/60; %[dev/s]
omega = 2*pi*PropRPS;
x = omega/V*r(i);
xi = r(i)/R;
lambda = V/(omega*R);
J = V/(PropRPS*D);
phi_t = lambda*(1+(zeta/2)); rad2deg(phi_t);
phi = atan((tan(phi_t))/xi); rad2deg(phi);
f = (B/2)*(1-xi)/(sin(phi_t));
F = (2/pi)*acos(exp(-f));
a = (zeta/2)*((cos(phi))^2)*(1-(epsilon*tan(phi)));
aprime = (zeta/(2*x))*((cos(phi))*(sin(phi)))*(1+(epsilon/tan(phi)));
W = (V*(1+a))/sin(phi);
Mach = W/343;
G = F*x*cos(phi)*sin(phi);%dogru
gamma = (2*pi*(V^2)*zeta*G)/(B*omega);
c = (gamma*2)/(W*Cl);
c_ft = c/0.3048;
sigma = (B*c)/(2*pi*r(i));
xint = xi;
I1 = integral(@(xint) 4*xint*G*(1-(epsilon*tan(phi))),xint,1);
I2 = integral(@(xint) lambda*(4*xint*G*(1-epsilon*tan(phi)))/2.*xint*(1+epsilon/tan(phi))*sin(phi)*cos(phi),xint,1);
J1 = integral(@(xint) 4*xint*G*(1+epsilon/tan(phi)),xint,1);
J2 = integral(@(xint) ((4*xint*G*(1+epsilon/tan(phi)))/2)*(1-epsilon*tan(phi))*((cos(phi))^2),xint,1);
% Pc = (SHP/(2*rho*(PropRPS^3)*(D^5)))
Pc = 0.0402;
ccc = J1/2*J2;
newzeta_ps = (-1*(ccc))+sqrt((ccc^2)+Pc/J2);
Tc = (I1*zeta)-(I2*(zeta^2));
eta = (Tc/Pc)*J;
formatSpec = '%9.2f %9.3f %9.3f %9.4f %9.2f %9.4f %9.4f \n';
disp(' phi zeta newzeta Tc eta a aprime')
disp(' ______ ______ ______ ______ ______ ______ ______')
fprintf(formatSpec,rad2deg(phi),zeta, newzeta_ps, Tc, eta, a, aprime);
2 Kommentare
Torsten
am 3 Apr. 2022
xint as lower bound of integration for your integrals is wrong.
It mustn't be zeta, but zeta0 which is a fixed value.
Antworten (0)
Siehe auch
Kategorien
Mehr zu Gamma Functions finden Sie in Help Center und File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!