|
|
Post by Johansson on Jul 13, 2012 23:31:23 GMT -5
Yup, but won´t it get rather messy if there is a leak somewhere since the pressure washer gives full flow instantly? Hydroforming with pressure washers is neat, takes some practice to find the right shape for the flat projections though.  |
|
|
|
Post by Johansson on Oct 1, 2012 15:06:25 GMT -5
Finally some inspiration to work on the rocket engine again, the temps are below freezing now in the mornings so that is a good reminder that Speed Weekend is not very far away and I need to up the pace a bit.  A shopping list for the tank pressurisation system was made so next up is the local hydraulic store!  Cheers! /Anders |
|
sven
Veteran Member
Joined: February 2012
Posts: 102
|
Post by sven on Oct 1, 2012 15:12:33 GMT -5
Nice drawings Anders, hope you gonna get it run before speed weekend Maybe I have to came to Sweden do see this thing with my own eyes  Sven |
|
|
|
Post by Johansson on Oct 1, 2012 15:54:20 GMT -5
Perhaps I will send a piece or two flying your way when I test run it. =)
|
|
sven
Veteran Member
Joined: February 2012
Posts: 102
|
Post by sven on Oct 2, 2012 10:34:52 GMT -5
;D Better lets hope there's no flying objects, and every things gonna work for you fine.
Sven
|
|
|
|
Post by Johansson on Oct 3, 2012 0:26:36 GMT -5
I hope so too, not much time for redesigns if I am to make it in time for Speed Weekend. I bought a bag full of hydraulic couplings and a pair of high pressure hoses yesterday, unfortunately the guy pressing the hoses got it wrong and didn´t fit the right connections to the hoses so I will have to go back there today and kick him in the balls. Cheers! /Anders |
|
sven
Veteran Member
Joined: February 2012
Posts: 102
|
Post by sven on Oct 3, 2012 10:10:02 GMT -5
Do not kick to hard, otherways he s not able to do it properly. Just in case stand next to him, and if he do it wong again kick him harder ;D Hydraulic couplings and hoses are not that cheap to play like that, hope you get it right this time Sven |
|
|
|
Post by Johansson on Oct 4, 2012 18:02:04 GMT -5
The tank pressurisation system is finished and tested!  I scrapped the old half finished system and made a new one on top of the propellant tanks, since I will be filling the NOX tank through the same pipes I assume that the lines should be steadily dropping from the fill tank to the race tank. I haven´t got access to a NOX pump so I will try to gravity fill the tank instead.  The regulator got presssure gauges fitted to both inlet and outlet so I can monitor the pressure before the run and video tape it during the firing of the engine, a third pressure gauge showing the combustion pressure will be fitted next to these ones so one camera can capture everything I need to know.  I tested the regulator and it worked perfectly, a smooth increase in pressure up to 40 bar (didn´t test higher than that for some reason) so it was a great buy! Thank you Aeroconsystems.com! Some kind of thrust stand will also be made, a friend of mine is gathering parts for a strain gauge build so hopefully he will have it ready in time. Cheers! /Anders |
|
|
|
Post by racket on Oct 5, 2012 1:10:50 GMT -5
Hi Anders
Theres something about hydraulic fittings that inspires confidence .........................she's looking good :-)
Cheers
John
|
|
|
|
Post by Johansson on Oct 5, 2012 2:06:29 GMT -5
I know what you mean, making things right the first time comes with age and bitter experience I guess. 10 years ago I would probably have used some old propane hoses... |
|
|
|
Post by racket on Oct 5, 2012 4:19:05 GMT -5
Hi Anders
LOL......................old propane hoses , ........ I have to admit I've got a couple of them in my shed cupboard , I had to replace the one on my plumbers torch earlier this year , so threw the old one in the cupboard just in case I need a bit of oil tank breather hose at some time in the future ..............that plumbers torch hose only lasted 40 years :-( ...............the replacement hose had a warning that I needed to replace it every 5 years ,...............bugger that,...... I'll wait until I start smelling gas for a year or so like I did with the old one ;-)
Cheers
John
|
|
mator
Junior Member
Joined: January 2012
Posts: 76
|
Post by mator on Oct 5, 2012 10:52:56 GMT -5
Hi!!! It smell of NOX in the air)))))) (Rocket burn is very soon)
Where did yours chamber pressure sensors are placed?
|
|
|
|
Post by Johansson on Oct 5, 2012 16:00:42 GMT -5
John: Only 40 years?!? I hope you saved the receipt. mator: Yup, not very far away now. The chamber pressure tap is placed in the injector plate so it is sitting just besides the injectors. |
|
mator
Junior Member
Joined: January 2012
Posts: 76
|
Post by mator on Oct 7, 2012 10:54:27 GMT -5
mator: Yup, not very far away now. The chamber pressure tap is placed in the injector plate so it is sitting just besides the injectors. Oukey!!! |
|
|
|
Post by britishrocket on Oct 8, 2012 7:42:15 GMT -5
Hi Anders,
Its all looking good. It will be very interesting to see the first firing, I will be watching closely!
I have thought a lot about where the chamber pressure sensor ought to go myself. In theory I think it should be sited a little before the convergent portion of the nozzle. At this point the reaction should be fairly complete and the pressure stable. Apparently the pressure can spike up a little as the gases enter the convergent portion.
The above of course assumes non-shifting equilibrium of the combustion products, which in small chambers like ours, even given enough L*, might not be the case. Maybe the answer is to have more than one sensor, one at the injector end like yours and one close to the end of the chamber (but before the convergence) and average the value.
Good luck with the rest of your build Anders,
Carl.
|
|
