Noise, size, and bypass?

From:         Bob_Crownfield <Bob_crownfield@qc.edu>
Organization: City University of New York/University Computer Center
Date:         20 Dec 95 15:52:07 
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When I watch a 727, the  engines are small diameter, and very noisy.

A DC-10 has larger engines which are apparently more powerfull, and less
noisy.

Last manual I saw said EPR maxed at about 2.2 if I remember that far
back.

Is there a relation between diameter, EPR,thrust, and noise?

I assume (Yes,I know about ass u me!) that EPR and exhaust velocity are
directly related to noise. How does bypass relate, if at all? It seems
that thrust and noise can vary very widely from engine type to engine
type.

Why is the 737 engine narrow and long, while the DC-10 engine is much
wider, and relatively shorter?

Why...  No, I will stop here!