cheap ramjet

[Cita]

ramjet made of car fire exthinghuisher steel bottle.
Unscrew valve at top of bottle and remove powder.
Drill 50 mm diameter hole in bottom of bottle with circular saw.
Get stainless steel kitchen sink retainer and grind out circular part with holes.This will give you a cone with a flange.
Adjust outside rim (flange) of sink retainer to fit on bottom of steel bottle and drill 3mm holes evenly spaced through retainer and bottom of bottle.
Secure cone to bottom with stainless steel 3mm bolts and nuts.

50mm from top of bottle drill 8mm hole in one side and 6mm hole in opposite side.

Fuell supply and flameholder is 8mm stainless steel tube 30mm longer than diameter of bottle.
On one end of tube weld 6mm steel bolt (you can cut off the hex head and slide the bolt 5mm into the tube and weld)
File weld flush with tube.

Drill 8 one (1) mm holes along length of tube starting 7mm from 6mm bolt weld and ending 7mm less than inner diameter of steel bottle ,measured from top of weld.

Slide fuel tube through 8mm hole in steel bottle and push through untill 6mm bolt is produting through 6mm hole on opposite side and secure with nut, make sure the 1mm holes facing towards the top of the bottle (valve hole).

Cita

[Zippiot]

how well does she work? i take it from the heavy discoloration that it starts up and runs

[Cita]

No problem in starting with propane.
Very good combustion.
The sudden expansion chamber was working beyond expectation.
By far the best ramjet I ever made.

Cita

[leo]

How big is the hole on the top where you unscrew the valve?.
It must be smaller than the exhaust hole I suppose.
Did you get some trust out off it?.
Looks like the not so aerodynamically front and back could interfere whit that.
With what where you blowing it?.
Just curious.

Leo.

[Cita]

How big is the hole on the top where you unscrew the valve?.
It must be smaller than the exhaust hole I suppose.
Did you get some trust out off it?.
Looks like the not so aerodynamically front and back could interfere whit that.
With what where you blowing it?.
Just curious.

Leo.

-will measure it but guestimate is 30mm diameter

-we did get thrust but didn't had the equipement to measure.engine and anchor plate moved towards the blower under full power.

-outside aerodynamics were not our first concern.we are not NASA but just a couple of guys having fun.

Cita

[Zippiot]

something to remember, those cylinders arent meant for high temps...

just an fyi