PD-01 Jet Engine

[madpatty]

Hi Chris,
The addition of gasoline isn't risky.??.there are some leaks near the turbine end because it is clamp type connection.

The spark plug is just near the 90degree step near the dump region.

Cheers,
Patty

[racket]

Hi Patty

Looking good :-)

Your perseverance has paid off , well done.

Cheers
John

[finiteparts]

If you mix in a small amount of gasoline, it isn't that risky...mind you take the same precautions that you would with any flammable liquid. I tried to find the proportions in JP-3, but I couldn't find the mixture ratios...if I find it, I will let you know.

How does the spark plug look after the runs? Is it getting really hot (or melted?) or is it covered with soot? That might tell you if you are in the right location.

Good luck!

Chris

[madpatty]

Hi Chris,
I will take the spark plug off and let u know....

BTW how should it be looking if its in the right spot?
Melted?

Cheers,
Patty

[ernie wrenn]

I run 50/50 % diesel and regular gas in my J-34... lights easy and does a great burner pops..

ernie

[madpatty]

Hi Guys,
i experimented with 3:7 ratio of gas and diesel but still same ignition problems.
The mixture was quite flammable as it instantly took fire with a match stick but still engine needed to be brought back to mere 4-5 psi for the afterburner to ignite.

Now is this due to low energy spark or bad dump section.

But once afterburner is ON it never flutters or any shows other problem.









cheers,
Patty

[racket]

Hi Patty

Where exactly is your ignition(spark plug) situation ??

What distance ( millimetres or inches) downstream of the "step" ??

It needs be positioned in an area of suitable fuel/air mixture.

Cheers
John

[madpatty]

Hi Racket,
The sparkplug's sparking point is about 25 mm downstream of the step.

Cheers,
Patty

[cobrajet]

Are you doing this for added thrust or just to see if you can get it working, for the effect?

[madpatty]

Hi Cobrajet,
I want to get it working as much properly as i can...just that is my motive.

Cheers,
Patty

[racket]

Hi Patty

I notice that your A/B wall has some dark area near the step , is your sparkplug situated in that dark area or the glowing area ??

Your A/B appears to be burning right back to the step from the colouration pattern , something we should expect with such a relatively large area A/B .

The only solution to your ignition problems is to try fitting the plug in different positions , possibly place it a bit further downstream , the AiResearch Low Cost Jet engine had its sparkplug positioned 1.6 inches - 40mm downstream of the step.

Depending on how well your fuel is "evaporating" you may need to allow a bit more time/distance for a flammable mixture to be present at the spark .

You're not the only one that has problems getting ignition at any other than low P2s , finding the perfect spot for the sparkplug can be a problem .

Cheers
John

[madpatty]

Hi Racket,
I didn take a picture of afterburner from that angle so its sort of difficult to tell if plug is located in that area or not...

But some speculation, it is not far from that area...i will try and change the location to further downstream and then note the effect.

Cheers,
Patty

[madpatty]

Hi Guys,

As far as the present performance of the engine is concerned i am pretty much satisfied with its performance at least on gaseous fuel.
But i am not at all satisfied with the test runs using liquid fuel(diesel).

During a month or so back i did some test runs on diesel and got the NGVs melted or at least the temperatures were very high just near the NGVs every time i ran the engine on liquid fuel.

Theres one more thing.

The evaps are seeing quite an amount of heat at their primary end according to what their primary end tips are telling BUT their tertiary end looks perfectly good.

This may be good as all combustion is occurring near the primary end but still i am looking for an explanantion about why this is happening because nothing shows up in TOTs(when on gaseous fuel) as they are comparatively much better lately.

Now i am afraid of running my engine on liquid fuel as i don't want to burn my NGVs again  so currently i don't know where to start making some improvements before making any further test runs on liquid fuel.
Need some help.

Cheers,
Patty

[Richard OConnell]

Patty, I looked back through the thread and havent found any pics of your flame holder setup. I'm wondering if that may be the cause of some of your woes.

[madpatty]

Hi Admin,

Flame holder setup?
I guess u are asking about the flametube....or what?

Cheers,
Patty