17-01-2023, 09:26 PM
Those are Lockwood-Hiller style pulse jets. It's basically a specially tuned, resonant pipe. No valves at all. The V1 used a valve style Argus engine where you effectively have a bunch of one way valves in the mouth of the tube.
Describing them as rockets is wrong since they use external air as an oxidiser whereas rockets that need oxygen carry their own fuel and oxidiser.
These might need some air flow to get them started (for these hobby ones compressed air or leaf blower usually) but then will run stationary as others have noted. The Argus engine on the V1 was started on compressed air, it doesn't have to be moving. They launched them up ramps using potassium permanganate and hydrogen peroxide to generate steam to move a piston in the launcher (like on aircraft carriers) presumably to get the whole bomb up to flying speed quickly. The engine was started before they shot it up the ramp.
Also different to a ram jet which does need to be travelling at high speed before they will work. The SR-71 aircraft engines operated as turbo-ram jets at high speeds. Strapping a J58 on an Austin 7 would be something to see!
Bruce Simpson in NZ did a lot of work on pulse jets quite some time ago: https://aardvark.co.nz/pjet/
I've always wanted to make a pulse jet but ended up making a turbo jet from an old turbochargers instead (over 20 years ago). I've recently been collecting parts to make another, smaller, more portable one.
Simon
Describing them as rockets is wrong since they use external air as an oxidiser whereas rockets that need oxygen carry their own fuel and oxidiser.
These might need some air flow to get them started (for these hobby ones compressed air or leaf blower usually) but then will run stationary as others have noted. The Argus engine on the V1 was started on compressed air, it doesn't have to be moving. They launched them up ramps using potassium permanganate and hydrogen peroxide to generate steam to move a piston in the launcher (like on aircraft carriers) presumably to get the whole bomb up to flying speed quickly. The engine was started before they shot it up the ramp.
Also different to a ram jet which does need to be travelling at high speed before they will work. The SR-71 aircraft engines operated as turbo-ram jets at high speeds. Strapping a J58 on an Austin 7 would be something to see!
Bruce Simpson in NZ did a lot of work on pulse jets quite some time ago: https://aardvark.co.nz/pjet/
I've always wanted to make a pulse jet but ended up making a turbo jet from an old turbochargers instead (over 20 years ago). I've recently been collecting parts to make another, smaller, more portable one.
Simon