Plotting Sound Pressure Level

Hi,

So I am trying to plot the eqution:

The final solution should look like what is attached. I constructed it using a loop but I don't think I'm follwoing the right steps.. For some reason it just says R is equal to 1000 and does not give me values between 1 to 1000.

r = 45;
alpha = .005;
W = .01;
Wref = 1*10^-12;
Lw = 10*log(W/Wref)

for R = 1:1000
    Lp(R) = Lw-10*log10(2*pi*r^2)-alpha*R;
end

Thanks, anything would help.

[Articat]

little r is the radius of the turbine.

[madhan ravi]

are you sure the formula is right?

Answer 1

[Image Analyst]

Instead of

for R = 1:1000
    Lp(R) = Lw-10*log10(2*pi*r^2)-alpha*R;
end

do it vectorized

alpha = .005;
W = .01;
Wref = 1*10^-12;
Lw = 10*log(W/Wref)
R = 1 : 1000
Lp = Lw - 10*log10(2*pi*R.^2) - alpha*R;
plot(R, Lp, 'b-', 'LineWidth', 2)
grid on;
xlabel('R', 'FontSize', 15);
ylabel('Lw', 'FontSize', 15);

This assumes your formula for Lw is correct.

[Articat]

Thank you!

[Image Analyst]

Are we done yet? What's still needed for you to "Accept this answer"?