Looked into this on my break today, seems that it could help those with drone. I made a quick matlab function to solve this for you. For instance if you are experiencing drone at 2500 rpm's, and the temperature at the point in which you wish to place the resonator is 350 degrees f. Then that would require a resonation chamber that is 34 inches long.
Here is the script:
function [L] = helmholtz_DMA (temp,rpm,cyl)
%Helmholtz resonator function
%5/9/2013
%INPUT:
%temp=degrees ferinheight
%cyl= number of cylinders%rpm= rpm in which drone occurs
%OUTPUT:
%L= length of 1/4 length resonator chamber
pulse=cyl/2;
F=rpm*pulse*(1/60);
T=(temp-32)/1.8;
V=331.3+.6*T;
L1=(V/F)/4;
L=L1*39.370;end
ans = 34.4330
Published with MATLAB® R2012b
Here is the script:
function [L] = helmholtz_DMA (temp,rpm,cyl)
%Helmholtz resonator function
%5/9/2013
%INPUT:
%temp=degrees ferinheight
%cyl= number of cylinders%rpm= rpm in which drone occurs
%OUTPUT:
%L= length of 1/4 length resonator chamber
pulse=cyl/2;
F=rpm*pulse*(1/60);
T=(temp-32)/1.8;
V=331.3+.6*T;
L1=(V/F)/4;
L=L1*39.370;end
ans = 34.4330
Published with MATLAB® R2012b