Two D15 grains makes a ???

"Gary C. Rosenfield" wrote in news:BEC0D0AC.144A3% snipped-for-privacy@powernet.net:

And a Blue Thunder F39 would not make the same?

Stock

Who said anything about HPR?? I said G33 - If I wasnt so lazy, I'd pull my G33 apart and check.

Sigh..ok, I should have said Perth.

No argument from me on that point.

Ah. Ok. Well I know I have used multigrains (sounds like a type of bread) in my 29-40/120

No offence to anyone, but I dont give a rats backside about NAR or TRA as they mean nothing here.

Thanks for all the info folks. Theres more to it than I thought.

I dont get it...both grains joined are smaller than some of the other

24mm grains - there was room to spare. I dont see how it could overpressurize. Why could it when a full length F grain won't?

Different nozzle size, therefore different chamber pressure.

-Kevin

The grains also burn on the ends; with two grains, you have four ends burning, not two. That's a significant different in burn surface area.

Read Gary's post; 1500 psi is NOT what these cases are designed for.

-Kevin

It's not the volume of propellant that's important, It's the exposed surface area that counts. In Your case, you doubled the burning surface, but kept the nozzle the same size. Ouch!

Thank you, Kevin. :-)

Gary

In article VwZme.36260$aB.25661@lakeread03, Kevin Trojanowski at snipped-for-privacy@nospam.cox.net wrote on 5/31/05 7:20 AM:

Kevin Trojanowski wrote in news:VwZme.36260$aB.25661@lakeread03:

Significant? How much extra area do you think those two ends add,for such a small diameter fuel slug? (compared to the longer C-slot) It's not like it were a 98mm motor with giant fuel slugs.

Total impulse comes from the mass and -velocity- of ejected gases and particulates.Velocity is related to chamber pressure and throat diameter. Does the E28 load have the same nozzle throat diameter as as D load? If the propellant burns at the same rate,to get a higher impulse,the chamber pressure has to increase,as I understand it.

snipped-for-privacy@mail.iinet.net.au (Impakt) wrote in news: snipped-for-privacy@news.iinet.net.au:

Different 24mm reloads have differing nozzle throat diameters. You need a good set of drill bits to measure it,it's not a big difference.

I used to have a list of some 24mm reloads and the throat diameters,but I can't find it.(so I could insure that the right nozzle was being used for the reload,or have the right drill bit on hand to clear out the flashing) You probably would have to go to a slightly larger throat to keep the case pressure within design specs.You probably got a higher impulse than an E28,too,at the risk of damaging your motor casing.

Designation Nozzle

18/20 D13-4W 01000-1 .077" 18/20 D13-7W 01000-1 .077" 18/20 D13-10W 01000-1 .077" 18/20 D24-4T 01050 .120" D21 18/20 D24-7T 01050 .120"D21 18/20 D24-10T 01050 .120" D21 24/40 D9-4W 01250 .086" E6/E15 24/40 D9-7W 01250 .086" E6/E15 24/40 D15-4T 01300 .104" E15/E28 24/40 D15-7T 01300 .104" E15/E28 24/40 E11-3J 01250 .086" E6/E15 24/40 E18-4W 01300 .104" E15/E28 24/40 E18-7W 01300 .104" E15/E28 24/40 E28-4T 01350 .141" E30/E50 24/40 E28-7T 01350 .141" E30/E50 24/40 F12-3J 01250 .086" E6/E15 24/40 F12-5J 01250 .086" E6/E15 24/40 F24-4W 01300-1 .125" 24/40 F24-7W 01300-1 .125" 24/40 F39-6T 01350-2 .166" 24/40 F39-9T 01350-2 .166" 29/40-120 E16-4W 01250 .086" E6/E15 29/40-120 E16-7W 01250 .086" E6/E15 29/40-120 E23-5T 01300-1 .125" 29/40-120 E23-8T 01300-1 .125" 29/40-120 F22-5J 01300 .104" E15/E28 29/40-120 F22-7J 01300 .104" E15/E28 29/40-120 F40-4W 01300-2 .136" 29/40-120 F40-7W 01300-2 .136" 29/40-120 F40-10W 01300-2 .136" 29/40-120 F52-5T 01350-1 .156" 29/40-120 F52-8T 01350-1 .156" 29/40-120 F52-11T 01350-1 .156" 29/40-120 G33-5J 01300-1 .125" 29/40-120 G33-7J 01300-1 .125" 29/40-120 G64-4W 01350 .141" E30/E50 29/40-120 G64-7W 01350 .141" E30/E50 29/40-120 G64-10W 01350 .141" E30/E50 29/60 F37W-S 01400 .104" F10/F30 29/60 F37W-M 01400 .104" F10/F30 29/60 F37W-L 01400 .104" F10/F30 29/60 F62T-S 01400-2 .125" F10/F30 29/60 F62T-M 01400-2 .125" F10/F30 29/60 F62T-L 01400-2 .125" F10/F30 29/100 G54W-S 01400-3 .136" F10/F30 29/100 G54W-M 01400-3 .136" F10/F30 29/100 G54W-L 01400-3 .136" F10/F30 29/100 G104T-S 01400-3 .136" F10/F30 29/100 G104T-M 01400-3 .136" F10/F30 29/100 G104T-L 01400-3 .136" F10/F30 29/120 G77R-S 01500 .180" F60/G80 29/120 G77R-M 01500 .180" F60/G80 29/120 G79W-S 01450-4 .172" G45/F60 29/120 G79W-M 01450-4 .172" G45/F60 29/120 G79W-L 01450-4 .172" G45/F60 29/180 G75J-S 01450-2 .156" G45/F60 29/180 G75J-M 01450-2 .156" G45/F60 29/180 H128W-S 01500 .180" F60/G80 29/180 H128W-M 01500 .180" F60/G80 29/180 H128W-L 01500 .180" F60/G80 29/180 H165R-S 01500 .180" F60/G80 29/180 H165R-M 01500 .180" F60/G80 29/180 H165R-L 01500 .180" F60/G80 29/180 H238T-S 01500-5 .228" F60/G80 29/180 H238T-M 01500-5 .228" F60/G80 29/180 H238T-L 01500-5 .228" F60/G80 29/240 H97J-S 01450-5 .177" F60/G45 29/240 H97J-M 01450-5 .177" F60/G45 29/240 H180W-S 01500-3 .213" F60/G80 29/240 H180W-M 01500-3 .213" F60/G80 29/240 H180W-L 01500-3 .213" F60/G80 29/240 H210R-M 01500-3 .213" F60/G80 29/240 H210R-L 01500-3 .213" F60/G80 29/240 H220T-S 01500-6 .266" F60/G80 29/240 H220T-M 01500-6 .266" F60/G80 29/240 H220T-L 01500-6 .266" F60/G80 29/360 H268R-M 01550 .291" NEW L2 29/360 H268R-L 01550 .291" NEW L2 29/360 I200W-S 01550 .291" NEW L2 29/360 I200W-M 01550 .291" NEW L2 29/360 I200W-L 01550 .291" NEW L2 38/120 G61W-S 01400-3 .136" F10/F30 38/120 G61W-M 01400-3 .136" F10/F30 38/120 G61W-L 01400-3 .136" F10/F30 38/120 G67R-S 01400-3 .136" F10/F30 38/120 G67R-M 01400-3 .136" F10/F30 38/240 H73J-S 01450 .141" F60/G45 38/240 H73J-M 01450 .141" F60/G45 38/240 H73J-L 01450 .141" F60/G45 38/240 H123W-S 01500 .180" F60/G80 38/240 H123W-M 01500 .180" F60/G80 38/240 H123W-L 01500 .180" F60/G80 38/240 H148R-S 01500 .180" F60/G80 38/240 H148R-M 01500 .180" F60/G80 38/240 H148R-L 01500 .180" F60/G80 38/240 H242T-S 01500-5 .228" F60/G80 38/240 H242T-M 01500-5 .228" F60/G80 38/240 H242T-L 01500-5 .228" F60/G80 38/360 H112J-S 01450-3 .161" F60/G45 38/360 H112J-M 01450-3 .161" F60/G45 38/360 H112J-L 01450-3 .161" F60/G45 38/360 I218R-S 01500-5 .228" F60/G80 38/360 I218R-M 01500-5 .228" F60/G80 38/360 I218R-L 01500-5 .228" F60/G80 38/360 I161W-S 01500-5 .228" F60/G80 38/360 I161W-M 01500-5 .228" F60/G80 38/360 I161W-L 01500-5 .228" F60/G80 38/360 I357T-S 01500-6 .266" F60/G80 38/360 I357T-M 01500-6 .266" F60/G80 38/360 I357T-L 01500-6 .266" F60/G80 38/480 I154J-S 01500 .180" F60/G80 38/480 I154J-M 01500 .180" F60/G80 38/480 I211W-S 01500-6 .266" F60/G80 38/480 I211W-M 01500-6 .266" F60/G80 38/480 I211W-L 01500-6 .266" F60/G80 38/480 I285R-S 01500-6 .266" F60/G80 38/480 I285R-M 01500-6 .266" F60/G80 38/480 I285R-L 01500-6 .266" F60/G80 38/480 I300T-S 01500-7 .313" F60/G80 38/480 I300T-M 01500-7 .313" F60/G80 38/480 I300T-L 01500-7 .313" F60/G80 38/600 I195J-S 01500 .180" F60/G80 38/600 I195J-M 01500 .180" F60/G80 38/600 I195J-L 01500 .180" F60/G80 38/600 I284W-S 01500-6 .266" F60/G80 38/600 I284W-M 01500-6 .266" F60/G80 38/600 I284W-L 01500-6 .266" F60/G80 38/600 I366R-S 01550 .291" NEW L2 38/600 I366R-M 01550 .291" NEW L2 38/600 I366R-L 01550 .291" NEW L2 38/600 I435T-S 01550-1 .313" NEW L2 38/600 I435T-M 01550-1 .313" NEW L2 38/600 I435T-L 01550-1 .313" NEW L2 38/720 I600R-M 01550 .291" NEW L2 38/720 J350W-S 01550 .291" NEW L2 38/720 J350W-M 01550 .291" NEW L2 38/720 J350W-L 01550 .291" NEW L2 38/720 J420R-S 01550 .291" NEW L2 38/720 J420R-M 01550 .291" NEW L2 38/720 J420R-L 01550 .291" NEW L2 38/1080 J570W-S 01550-2 .359" NEW L2 38/1080 J570W-M 01550-2 .359" NEW L2 38/1080 J570W-L 01550-2 .359" NEW L2

Hopefully this won't be as messed up as the last attempt.

Designation Nozzle

18/20 D13-4W 01000-1 .077" 18/20 D13-7W 01000-1 .077" 18/20 D13-10W 01000-1 .077" 18/20 D24-4T 01050 .120" D21 18/20 D24-7T 01050 .120"D21 18/20 D24-10T 01050 .120" D21 24/40 D9-4W 01250 .086" E6/E15 24/40 D9-7W 01250 .086" E6/E15 24/40 D15-4T 01300 .104" E15/E28 24/40 D15-7T 01300 .104" E15/E28 24/40 E11-3J 01250 .086" E6/E15 24/40 E18-4W 01300 .104" E15/E28 24/40 E18-7W 01300 .104" E15/E28 24/40 E28-4T 01350 .141" E30/E50 24/40 E28-7T 01350 .141" E30/E50 24/40 F12-3J 01250 .086" E6/E15 24/40 F12-5J 01250 .086" E6/E15 24/40 F24-4W 01300-1 .125" 24/40 F24-7W 01300-1 .125" 24/40 F39-6T 01350-2 .166" 24/40 F39-9T 01350-2 .166" 29/40-120 E16-4W 01250 .086" E6/E15 29/40-120 E16-7W 01250 .086" E6/E15 29/40-120 E23-5T 01300-1 .125" 29/40-120 E23-8T 01300-1 .125" 29/40-120 F22-5J 01300 .104" E15/E28 29/40-120 F22-7J 01300 .104" E15/E28 29/40-120 F40-4W 01300-2 .136" 29/40-120 F40-7W 01300-2 .136" 29/40-120 F40-10W 01300-2 .136" 29/40-120 F52-5T 01350-1 .156" 29/40-120 F52-8T 01350-1 .156" 29/40-120 F52-11T 01350-1 .156" 29/40-120 G33-5J 01300-1 .125" 29/40-120 G33-7J 01300-1 .125" 29/40-120 G64-4W 01350 .141" E30/E50 29/40-120 G64-7W 01350 .141" E30/E50 29/40-120 G64-10W 01350 .141" E30/E50 29/60 F37W-S 01400 .104" F10/F30 29/60 F37W-M 01400 .104" F10/F30 29/60 F37W-L 01400 .104" F10/F30 29/60 F62T-S 01400-2 .125" F10/F30 29/60 F62T-M 01400-2 .125" F10/F30 29/60 F62T-L 01400-2 .125" F10/F30 29/100 G54W-S 01400-3 .136" F10/F30 29/100 G54W-M 01400-3 .136" F10/F30 29/100 G54W-L 01400-3 .136" F10/F30 29/100 G104T-S 01400-3 .136" F10/F30 29/100 G104T-M 01400-3 .136" F10/F30 29/100 G104T-L 01400-3 .136" F10/F30 29/120 G77R-S 01500 .180" F60/G80 29/120 G77R-M 01500 .180" F60/G80 29/120 G79W-S 01450-4 .172" G45/F60 29/120 G79W-M 01450-4 .172" G45/F60 29/120 G79W-L 01450-4 .172" G45/F60 29/180 G75J-S 01450-2 .156" G45/F60 29/180 G75J-M 01450-2 .156" G45/F60 29/180 H128W-S 01500 .180" F60/G80 29/180 H128W-M 01500 .180" F60/G80 29/180 H128W-L 01500 .180" F60/G80 29/180 H165R-S 01500 .180" F60/G80 29/180 H165R-M 01500 .180" F60/G80 29/180 H165R-L 01500 .180" F60/G80 29/180 H238T-S 01500-5 .228" F60/G80 29/180 H238T-M 01500-5 .228" F60/G80 29/180 H238T-L 01500-5 .228" F60/G80 29/240 H97J-S 01450-5 .177" F60/G45 29/240 H97J-M 01450-5 .177" F60/G45 29/240 H180W-S 01500-3 .213" F60/G80 29/240 H180W-M 01500-3 .213" F60/G80 29/240 H180W-L 01500-3 .213" F60/G80 29/240 H210R-M 01500-3 .213" F60/G80 29/240 H210R-L 01500-3 .213" F60/G80 29/240 H220T-S 01500-6 .266" F60/G80 29/240 H220T-M 01500-6 .266" F60/G80 29/240 H220T-L 01500-6 .266" F60/G80 29/360 H268R-M 01550 .291" NEW L2 29/360 H268R-L 01550 .291" NEW L2 29/360 I200W-S 01550 .291" NEW L2 29/360 I200W-M 01550 .291" NEW L2 29/360 I200W-L 01550 .291" NEW L2 38/120 G61W-S 01400-3 .136" F10/F30 38/120 G61W-M 01400-3 .136" F10/F30 38/120 G61W-L 01400-3 .136" F10/F30 38/120 G67R-S 01400-3 .136" F10/F30 38/120 G67R-M 01400-3 .136" F10/F30 38/240 H73J-S 01450 .141" F60/G45 38/240 H73J-M 01450 .141" F60/G45 38/240 H73J-L 01450 .141" F60/G45 38/240 H123W-S 01500 .180" F60/G80 38/240 H123W-M 01500 .180" F60/G80 38/240 H123W-L 01500 .180" F60/G80 38/240 H148R-S 01500 .180" F60/G80 38/240 H148R-M 01500 .180" F60/G80 38/240 H148R-L 01500 .180" F60/G80 38/240 H242T-S 01500-5 .228" F60/G80 38/240 H242T-M 01500-5 .228" F60/G80 38/240 H242T-L 01500-5 .228" F60/G80 38/360 H112J-S 01450-3 .161" F60/G45 38/360 H112J-M 01450-3 .161" F60/G45 38/360 H112J-L 01450-3 .161" F60/G45 38/360 I218R-S 01500-5 .228" F60/G80 38/360 I218R-M 01500-5 .228" F60/G80 38/360 I218R-L 01500-5 .228" F60/G80 38/360 I161W-S 01500-5 .228" F60/G80 38/360 I161W-M 01500-5 .228" F60/G80 38/360 I161W-L 01500-5 .228" F60/G80 38/360 I357T-S 01500-6 .266" F60/G80 38/360 I357T-M 01500-6 .266" F60/G80 38/360 I357T-L 01500-6 .266" F60/G80 38/480 I154J-S 01500 .180" F60/G80 38/480 I154J-M 01500 .180" F60/G80 38/480 I211W-S 01500-6 .266" F60/G80 38/480 I211W-M 01500-6 .266" F60/G80 38/480 I211W-L 01500-6 .266" F60/G80 38/480 I285R-S 01500-6 .266" F60/G80 38/480 I285R-M 01500-6 .266" F60/G80 38/480 I285R-L 01500-6 .266" F60/G80 38/480 I300T-S 01500-7 .313" F60/G80 38/480 I300T-M 01500-7 .313" F60/G80 38/480 I300T-L 01500-7 .313" F60/G80 38/600 I195J-S 01500 .180" F60/G80 38/600 I195J-M 01500 .180" F60/G80 38/600 I195J-L 01500 .180" F60/G80 38/600 I284W-S 01500-6 .266" F60/G80 38/600 I284W-M 01500-6 .266" F60/G80 38/600 I284W-L 01500-6 .266" F60/G80 38/600 I366R-S 01550 .291" NEW L2 38/600 I366R-M 01550 .291" NEW L2 38/600 I366R-L 01550 .291" NEW L2 38/600 I435T-S 01550-1 .313" NEW L2 38/600 I435T-M 01550-1 .313" NEW L2 38/600 I435T-L 01550-1 .313" NEW L2 38/720 I600R-M 01550 .291" NEW L2 38/720 J350W-S 01550 .291" NEW L2 38/720 J350W-M 01550 .291" NEW L2 38/720 J350W-L 01550 .291" NEW L2 38/720 J420R-S 01550 .291" NEW L2 38/720 J420R-M 01550 .291" NEW L2 38/720 J420R-L 01550 .291" NEW L2 38/1080 J570W-S 01550-2 .359" NEW L2 38/1080 J570W-M 01550-2 .359" NEW L2 38/1080 J570W-L 01550-2 .359" NEW L2

The F39 doesn't have the cut down the center, increasing the burn area.

Bob Kaplow NAR # 18L TRA # "Impeach the TRA BoD" >>> To reply, remove the TRABoD!

The G33 is an HPR reload. Check the cert data for it on the NAR web site.

Sorry. I missed the ".au" in your post and didn't realize how far away you were...

Bob Kaplow NAR # 18L TRA # "Impeach the TRA BoD" >>> To reply, remove the TRABoD!

Because the full F doesn't have the seam between the two halves.

Bob Kaplow NAR # 18L TRA # "Impeach the TRA BoD" >>> To reply, remove the TRABoD!

Nice information, but anyone using it needs to look carefully at the spacing -- on initial display, it appeared that the first line read '01000-1.077"'; when reformatted to a different font, the space between the "01000-1" and the .077" became readily apparent.

-Kevin

D15 - .104" throat E28 - .141" throat

I would say that the addition of two ends is a greater difference on a smaller motor than on a larger one, plus you're not adding just the ends, but doubling the entire burn surface area.

Regardless, running a case beyond its design parameters is a recipe for disaster. Every time you do it, you put more stress on the hardware, which may ultimately result in it failing on a certified load.

-Kevin

Anyone willing to try an 18mm case with a 1.077" nozzle is encouraged to discuss the inversion of the space-time continuim that they have encountered...

David Erbas-White

Yes, that would be rather generous (and appropriate) of them, I do believe.

The question, of course, is what effect that inversion has on a motor's thrust.....

-Kevin