Pulsejet in Singapore

[tobiasbt]

Hello

I'm a new member here, and would like to ask for advises in building and running the pulsejet.

I'm planning to build a valveless pulsejet for research in Singapore. Rather than using it for thrust, the company I worked for wanted to see if the exhaust gas can be applied for drying. The thing is, this is the very first time we're building something like this, and I would like to hear some advises on these issues:

1. Design
For the initial experiments, I want to build a very simple design. Is it possible to run a 'straight' type of valveless pulsejet?
Basically, I got the dimensions from the Pulsejet Calculator v1.4 (for a 5 kg thrust), but without the valves, and will be using a sparkplug for starting.
Also, I plan to use propane for fuel.

Will it work? I understand that in the end we still need to 'play around with it' to get it to run. But of course I hope I don't miss out any vital elements

2. Safety
I have read in this forum that propane itself is not combustible without air, thus we won't have any 'flash-back'. Still, my supervisors are very concerned about the safety of running a pulsejet - they're worried about the possibility of an explosion, fire hazards, loud noise, etc.
So, they propose to build something like a protective hood/encasement for it.

Has anybody encountered any accidents with the pulsejet? Or, has anybody build this kind of encasement before?

Ok, I think that's all for now from me..sorry for the proper lack of introduction. The research is still in a preliminary stages, and I don't think there is anybody working on a pulsejet in Singapore..thus I turn to this forum

Thanks!!

Regards,
Toby

[ganuganu]

use these plans made by me, its really a quick starter and uses only straight pipes puts out 10pounds thrust.

[tobiasbt]

@ganuganu:

Thanks!! Have you tried building it yourself?

[Jutte]

Hi Tobiasbt,
Valveless Pulse jets have been/and are used in the drying of various slurried materials.
Most are a deriative of the Lockwood Valveless. I suggest you do an internet search on the topic of Industrial Drying.
The main problems are noise, fuel consumption and vibration absorption.
But for large volume drying of industrial materials they do the job effectively.
Hope that helps...

[ganuganu]

yes, here is my engine video and pictures..

http://www.youtube.com/watch?v=P20LLkbpZSU
http://www.youtube.com/watch?v=YunxVl2c9oY

[tobiasbt]

@jutte: Thanks for the info. I'm still doing some reading on the subject, and wanted to have some hands-on experience with a pulse combustor (pulse jet), hence the need for experiment.

@ganuganu: Nice vids you got there How did you start the jet anyway? Sparkplug? Any concern for fire or explosion?

Thanks !!

[ganuganu]

no sparkplugs used sparkler to start the engine. And there is no risk for explosion seriously you will enjoy starting it.

[Mike Everman]

Fire, yes there is a risk. Do it outside, keep the wind at your back, safety glasses, gloves, long sleeve cotton shirt, etc. Propane is a good fuel, fireballs go up and do not stick to you if you find yourself in the wrong place.

[tobiasbt]

@ Mike: Thanks. I will keep that advice in mind.

@ganu: btw, have you ever measured the flow speed and temperature from the exhaust? Any idea how to measure them? I was thinking to use thermocouples for the temperature, and maybe an airflow meter for the speed. But if the temperature is too high, I'm not sure if the airflow meter can withstand it.

Thanks for the replies, everyone

[Mike Everman]

for average airspeed, if you can get an aircraft airspeed indicator you can just put a long metal tube on it with a bend. the heat will not get to the indicator.

[tobiasbt]

Hello everyone,

Sorry for the late reply.

I decided to try and build a small pulsejet for my experiment. As this is my very first time working with a pulsejet, I'm thinking of making something simple and small.
Referring to the rough sketch attached, do you guys think it will work?
At this stage, my only concern is to get it work (having a pulsating combustion).

Oh, and the unit in the sketch is in milimeters.

Thanks!!

Regards,
Toby