[AR] Re: Igniter Popping Sound
- From: Norman Yarvin <yarvin@xxxxxxxxxxxx>
- To: arocket@xxxxxxxxxxxxx
- Date: Mon, 22 Sep 2014 14:19:11 -0400
Ah, okay; I misread your earlier comment about moving the GOX port
"upstream", thinking you meant upstream along the igniter axis. Well,
also, the bit about the two jets impinging on the walls made me think
they weren't impinging on each other. With them impinging at 90
degrees, I guess what you're getting is mostly just the fuel jet
punching through the oxygen jet (due to the oxygen being gaseous and
less dense), with the bulk of both jets then going on to hit the
walls. At the 180 degrees of Graham's setup, they have more
opportunity to fight each other.
On Mon, Sep 22, 2014 at 11:05:32AM -0500, Robert Watzlavick wrote:
>They impinge- in this sketch:
>
>http://watzlavick.com/robert/rocket/igniters/drawings/igniter6-nodims.pdf
>
>The two ports shown in the upper left are 90 deg apart and are the GOX and
>fuel ports. They are lined up at the same point longitudinally. The 3rd port
>located a bit downstream is for the pressure tap. The spark plug threads into
>the end. I was worried about the spark plug being upstream and not igniting
>the mixture but it seems to be reliable. Except for the V5 igniter which
>didn't start as previously mentioned, probably because the orifices were
>pointed downstream.
>
>-Bob
>
>> On Sep 22, 2014, at 10:14, "Graham Sortino" <dmarc-noreply@xxxxxxxxxxxxx>
>> (Redacted sender "gnsortino@xxxxxxxxx" for DMARC) wrote:
>>
>> no worries.. Actually, I appreciate the second opinion on my math. Thanks
>> too for the additional details.
>>
>> If you don’t mind me asking... to confirm regarding Norman's observation are
>> your fuel/ox jets deliberately not impinging directly upon each other in the
>> chamber? If so is the GOX line slightly further upstream of the fuel (or
>> vice versa)? I think I had missed that point when I originally read the
>> description of your design.
>>
>>
>>
>> On Sunday, September 21, 2014 10:49 PM, Robert Watzlavick
>> <rocket@xxxxxxxxxxxxxx> wrote:
>>
>>
>> Oops - I made a mistake. I thought your last run was 0.01 lbm/s but it is
>> 0.01 kg/s (0.022 lbm/s) which is right in the ballpark. So forget the last
>> paragraph.
>>
>> -Bob
>>
>>
>>
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