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  • Category: Mechanical
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Boost pressures and EGTs   Message List  
Reply Message #51277 of 51571 |
Re: [DIYGasTurbines] Re: Boost pressures and EGTs

I'm going to do some work on it tonight. I haven't taken the flame tube out yet to inspect how it is burning. Thanks for the info on the injector.

The inlet on the turbo is 2.5 inches. I used that measurement to calculate flame tube specs roughly.

Ken
Sent on the Sprint® Now Network from my BlackBerry®
From: "John WALLIS \(Racketmotorman\)" <racketmotorman@...>
Sender: DIYGasTurbines@yahoogroups.com
Date: Fri, 27 Jan 2012 07:51:21 +1000
To: <DIYGasTurbines@yahoogroups.com>
ReplyTo: DIYGasTurbines@yahoogroups.com
Subject: Re: [DIYGasTurbines] Re: Boost pressures and EGTs

 

Hi Ken
 
The rpm limit will depend on the wheel diameter as the Group has an upper tip speed limit of 1450 ft/sec for safety reasons ,  so measure your compressor wheel diameter , put the number into Jetspecs Turbo Analysis  and it will give you a rpm limit for your engine .
 
Cheers
John
 
 
----- Original Message -----
Sent: Thursday, January 26, 2012 11:46 PM
Subject: Re: [DIYGasTurbines] Re: Boost pressures and EGTs

 

I ordered a tach that goes to 99,999 rpm. It should be here today. What kind of RPM should I be looking for?

Ken

Sent on the Sprint® Now Network from my BlackBerry®
From: "mot_mole" <jnissen@...>
Date: Thu, 26 Jan 2012 07:07:54 -0000
Subject: [DIYGasTurbines] Re: Boost pressures and EGTs

 

Ken fairly low T4 temps. DO you have a jet nozzle on it or just a straight pipe? At 22 to 24 PSI that is really pushing it. Be careful of over revving. Do you have a tach for it?

Sounds like it's really moving.

--- In DIYGasTurbines@yahoogroups.com, "Ken Herbert" <sswhuevos@...> wrote:
>
> I put a boost gauge on my gas turbine last weekend and I saw about 22-24 PSI at full throttle running on propane. My EGT at turbine and thrust tube was about 750-800F. The compressor side was around 1600F. Is this a good place I need to be?
>
> http://www.youtube.com/user/hyprmtr?blend=1&ob=video-mustangbase
>
>
> Ken
>
Thu Jan 26, 2012 9:55 pm

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Message #51277 of 51571 |
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I put a boost gauge on my gas turbine last weekend and I saw about 22-24 PSI at full throttle running on propane. My EGT at turbine and thrust tube was about... 		Ken Herbert
sswhuevos... Offline Send Email 		Jan 26, 2012
6:06 am

Ken fairly low T4 temps. DO you have a jet nozzle on it or just a straight pipe? At 22 to 24 PSI that is really pushing it. Be careful of over revving. Do you...
mot_mole Offline Send Email Jan 26, 2012
7:07 am

I ordered a tach that goes to 99,999 rpm. It should be here today. What kind of RPM should I be looking for? Ken Sent on the Sprint® Now Network from my...
sswhuevos@...
sswhuevos... Offline Send Email 		Jan 26, 2012
1:46 pm

Hi Ken I just had a look at the video and I'm a bit concerned about the turbine wheel temperature as it appears there is flames at the turbine , without any...
John WALLIS (Racketmo...
racketmotorman Offline Send Email 		Jan 26, 2012
8:21 am

The injector is just a 1/4 inch copper tube I put in a drill chuck and crimped down to almost nothing. The flame tube was built with a 4 inch exhaust tubing...
sswhuevos@...
sswhuevos... Offline Send Email 		Jan 26, 2012
1:45 pm

Hi Ken Injectors need to have "radial" holes (relative to the flametube axis) otherwise the propane will be injected too far down the flametube before ignition...
John WALLIS (Racketmo...
racketmotorman Offline Send Email 		Jan 26, 2012
9:45 pm

Hi Ken The rpm limit will depend on the wheel diameter as the Group has an upper tip speed limit of 1450 ft/sec for safety reasons , so measure your...
John WALLIS (Racketmo...
racketmotorman Offline Send Email 		Jan 26, 2012
9:51 pm

I'm going to do some work on it tonight. I haven't taken the flame tube out yet to inspect how it is burning. Thanks for the info on the injector. The inlet...
sswhuevos@...
sswhuevos... Offline Send Email 		Jan 26, 2012
9:56 pm

Hi Ken 2.5"inducer gives us 4.9 sq inches , we need ~3 times inducer area for our flametube crossection , so ~14.7 sq ins , or ~4.3 inch ID as a minimum...
John WALLIS (Racketmo...
racketmotorman Offline Send Email 		Jan 26, 2012
11:07 pm

I just took the flame tube out and inpected it. It seams as if the flame is traveling to far twards the turbine side. I think I will make another injector like...
Ken Herbert
sswhuevos... Offline Send Email 		Jan 27, 2012
1:34 am

Hi Ken Yep, she's running a bit hot at the outlet end of the flametube , ideally the flametube wall should be hottest in the primary zone where the fuel is...
John WALLIS (Racketmo...
racketmotorman Offline Send Email 		Jan 27, 2012
11:02 pm

I'm working on the new injector right now! I will run it tonight and see how it goes. I will try out my new tach also. Thank you so much for your help! Ken...
Ken Herbert
sswhuevos... Offline Send Email 		Jan 28, 2012
12:05 am

Hi Ken All the best with the next test , only too happy to help out :-) Cheers John ... From: Ken Herbert To: DIYGasTurbines@yahoogroups.com Sent: Saturday,...
John WALLIS (Racketmo...
racketmotorman Offline Send Email 		Jan 28, 2012
12:56 am

I did a lot of different testing this weekend and did not really change much in performance. I tried a radial injector and it did light and run but it would...
sswhuevos@...
sswhuevos... Offline Send Email 		Jan 30, 2012
4:47 pm

Hi Ken How many radial holes, and what size , in the injector that didn't work ?? .....................radial holes should cure problems not create them ,...
John WALLIS (Racketmo...
racketmotorman Offline Send Email 		Jan 30, 2012
9:54 pm

I am using a 1/4 inch copper tube that I mashed almost completely closed for the injector that works well. I made another injector the same way but I close it...
sswhuevos@...
sswhuevos... Offline Send Email 		Jan 30, 2012
10:24 pm

Hi Ken 3 radial holes in the fuel injector aren't enough as there are large "wedges" of the flametube crossection without any fuel , we need at least 6 holes...
John WALLIS (Racketmo...
racketmotorman Offline Send Email 		Jan 31, 2012
12:46 am

My SJ10 with an 1.70" compressor inducer idles at ~50,000 RPM with a P2 = 4 to 5 psig. For the injector, I used a brass threaded with 6 equally spaced 0.040"...
Mike Early
mearly22 Offline Send Email 		Jan 31, 2012
1:45 am
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