End Correction: An Idiot's Guide for Understanding Standing Waves

[R7ll]

Help with understanding end correction

I missed a lesson at school on end correction of standing waves in pipes. I have a vague understanding of them, but can anyone give me an idiot's guide to end correction? Most websites I've had a look at haven't been too helpful in explaining it.

Now, this is just a guess, but am I right to assume that if i detected a fundamental in a tube with one end open and one end closed, the wavelength of that wave is not four times the length of the tube, but actually four times the length of the tube, and four times the end correction added on top of that?
I also read somewhere that the end correction distance is something like 0.61 * r where r is the radius of the tube... is this correct
Thanks

 

[member 553083]

.End correction is the difference between the actual length of a tube and the length of the fundamental wave that is produced in it. This difference is due to the fact that when a wave reaches the end of a pipe, some of its energy is reflected back into the pipe rather than being transmitted through the end. This reflection causes the standing wave in the pipe to be shorter than the actual length of the pipe, and this difference is referred to as end correction. The amount of end correction depends on the type of end (open or closed) and the shape of the pipe. Generally speaking, a closed end pipe has more end correction than an open end pipe. The amount of end correction also depends on the radius of the pipe. For a closed end pipe, the end correction distance is roughly 0.61 times the radius of the pipe. So yes, if you detect a fundamental in a tube with one end open and one end closed, the wavelength of that wave will be four times the length of the tube plus four times the end correction.