PyroJoes Recipe for Beginners

[PyroJoe]

looks about like this:

[ganuganu]

thanks for the augmenter design..do you have any idea about the thrust specific fuel consumption.i think this engine doesnt have tsfc 1.

[PyroJoe]

"i think this engine doesnt have tsfc 1."
Where does this come from?

The Recipe is to get newbs in the game, if it doesn't fit your design criteria change it and report what you find.

[ganuganu]

actually i know TSFC= fuel consumption in pounds per hour/thrust in pounds

but in this i really dont know how to find the fuel consumed by the engine per hour for LPG gas.
if the fuel is liquid we can find easily..

[PyroJoe]

If I understand it correctly to determine TSFC on a static running engine:
The thrust would need to be measured accurately at a stable throttle setting.
A recorded accurate weight of the propane tank before and after a run.
A accurate method to capture the length of time per run.
Reasonably long runs would be needed. 4 to 5 minutes maybe?

Thats the basics, more detail can be added to the point of nausea.


The design of the fueling system can often have more effect on TSFC than the total engine design.

[metiz]

If you have a gram acurate scale that goes up to the weight of a propane tank you could try this: Put the tank on the scale and start the engine, throttle it to max power. check thrust and weight of the propane tank. take a stopwatch and record 1 minute. From the second you hit the on button, make a note of the exact weight of the propane tank. after the minute is up (exactly) take a look at the weight again. substract weight 2 from weight 1 and you have your fuel consumption for 1 minute of running at max throttle. You can calculate from there. For more acurate measurements, repeat the process 2 more times and take the average of the 3 weights you end up with

[ganuganu]

i will try this idea for this trial. And i have another question here how can i find the frequency of my pulsejet engine that is i want to know at what frequency the engine is working.

[PyroJoe]

SPEAR Software:
http://www.klingbeil.com/spear/

[ganuganu]

here i have flared the intake pipes and made the injector for the engine. going to test the engine tomorrow.

[metiz]

Flares! good man!

[ganuganu]

the engine gave only yellow flames didnt give any booming effect,i think its a failure design. so i thought to redesign the engine like this..

[PyroJoe]

Did you use vapor or liquid? In this trial was the intake length 19cm or 16.4cm? Keep in mind the main fuel line has been split 4 ways. The fuel velocity and pressure have been significantly reduced.

[ganuganu]

i used lpg gas as fuel and the intake length is 16.4cm

[metiz]

That engine will take a significant amount of gas. As Pyro mentioned, pressure and flow per injector will be reduced. You can try hooking up 2 tanks: one tank per 2 injectors.

[ganuganu]

ok then i have to throttle both the cylinder valves at the same time. I have a doubt here if some amount of yellow flames comes from the intake pipe is it due to the only reason "low gas pressure" through the intake pipe. i just thought to ask please clarify it.

update: I found four small holes in the weld near the combustion chamber do you think this may be the reason for getting yellow flames in the intake pipes. And also for the failure of the engine.