rtfm
Well-Known Member
Hi,
I may have spelled the name incorrectly, but does anyone remember the thread about the rather unusual exhaust pipe designed by (Harry?) Schwarz (sp?) It consisted of multiple exits from the exhaust pipe into a surrounding chamber, which then further allowed the exhaust gasses to escape via multiple smaller exits - dividing up the single exhaust pulse into many smaller and time-shifted pulses of much lower energy. There was quite a lot of chatter about it at the time. A prototype was made and fitted to a lawnmower, and the resultant sound was a gentle hiss - so silent that one could hear the engine internals quite clearly.
I've searched for the thread, but the HBA search engine really sucks.
With all the talk about electric motors at the moment, one of the persistent benefits quoted is how quiet electric motors are, and how much more enjoyable flying behind one is. Not to mention the benefit of not annoying neighbours.
It seems to me that fitting an exhaust of this type to an IC engine would provide the much-lauded benefit of quietness, while still preserving the endurance of an IC motor.
Anyone remember this?
Duncan
I may have spelled the name incorrectly, but does anyone remember the thread about the rather unusual exhaust pipe designed by (Harry?) Schwarz (sp?) It consisted of multiple exits from the exhaust pipe into a surrounding chamber, which then further allowed the exhaust gasses to escape via multiple smaller exits - dividing up the single exhaust pulse into many smaller and time-shifted pulses of much lower energy. There was quite a lot of chatter about it at the time. A prototype was made and fitted to a lawnmower, and the resultant sound was a gentle hiss - so silent that one could hear the engine internals quite clearly.
I've searched for the thread, but the HBA search engine really sucks.
With all the talk about electric motors at the moment, one of the persistent benefits quoted is how quiet electric motors are, and how much more enjoyable flying behind one is. Not to mention the benefit of not annoying neighbours.
It seems to me that fitting an exhaust of this type to an IC engine would provide the much-lauded benefit of quietness, while still preserving the endurance of an IC motor.
Anyone remember this?
Duncan
