[AR] Re: Igniter Popping Sound
- From: "Graham Sortino" <dmarc-noreply@xxxxxxxxxxxxx> (Redacted sender "gnsortino@xxxxxxxxx" for DMARC)
- To: "arocket@xxxxxxxxxxxxx" <arocket@xxxxxxxxxxxxx>
- Date: Thu, 30 Oct 2014 12:58:03 +0000 (UTC)
Thanks, I’m really excited I finally got this working.After going through this
somewhat frustrating process I feel like I have a muchbetter sense of how the
theoretical factors in producing ignition are appliedpractically. To answer
your question, yes, for example on this test
(http://wiki.fubarlabs.org/fubarwiki/GOX-Ethanol-Igniter-v2.ashx#CABE-AF-BI:_Test_E_Best_So_Far_6)I
thought the mixture ratio was about 1.5:1 but in reality it was only about
0.9:1. What I’m still not sure about though is why it wouldstill light
sometimes at 0.9:1 even though that is a fairly lean mixture ratio.I think it
could have something to do with the weather. Maybe I tested on a hotday one
time and it worked and then a cooler day another time and it did not.Or maybe
the igniter was already heated enough from prior tests so it did a better job
of atomizingthe propellants. I’m not too bothered bythis, though, since I know
that a ratio of 0.9:1 is too low. Generally, I’vebeen shooting for about a
1.3:1 for the igniter and I’ve been running about thesame for the main engine.
I’d like to bring the main engine down a bit tosomething like 1:1 to see if it
works so the main engine doesn’t run quite sohot. Also, I’ll try to get videos
up by this weekend but Iwant to do a nice write-up first to summarize findings.
On Thursday, October 30, 2014 7:23 AM, Robert Watzlavick
<rocket@xxxxxxxxxxxxxx> wrote:
Graham,
That is great news. I'm wondering if I didn't have similar issues since my
igniter valve orifices are also 3/64" and the downstream orifice diameter is
around 0.030. So I'm probably getting more pressure drop across the valve than
I anticipated. So if I understand this correctly, the mixture is leaner then
expected? Looking forward to seeing your videos.
-Bob
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