The cube/square relationship of volume to surface area means that smaller LVs have higher aero losses. You get similar effects with the minimum gauge of materials.
Danny, if you or anyone else would like, I could port that code to C, C++, or Java, since some people might find it easier to read or use that way. I was thinking of doing that anyway, since I'm one of those who, despite having started with QB, finds C-like languages more readable, but it occurred to me that others might find such a translation useful...
Quote from: strangequark on 03/27/2009 03:15 amSteven,Thanks for reminding me about HTP. I might have to think about acquiring some for my garage project. The catalytic decomposition eases ignition, and it doesn't have any nitrogen in it to murder your Isp.Be very, very careful! HTP is catalyzed by a lot of organic sustances, including leather and human skin. Have plenty of water around to dilute any spills and a shower for any one exposed. Never work alone as the pain from exposure can prevent someone from treating themself.IIRC, an amateur rocketry enthusiast died a couple of years ago working with HTP.Do plenty of research.
Steven,Thanks for reminding me about HTP. I might have to think about acquiring some for my garage project. The catalytic decomposition eases ignition, and it doesn't have any nitrogen in it to murder your Isp.
The "hypergolic with test engineers" issue is definitely not to be taken lightly.
That's true - smaller LV will have higher relative air drag. Can you, please, give some example of the effects that appear "with the minimum gauge of materials"? That's what interest me the most.
Note also that to get high mass ratios you need BIG rocket ships. That follows because there are minimum weights to many rocket parts. This is known as 'minimum gauge', meaning that you can't make it any thinner or lighter. Combustion chambers have to be rugged. Pipes must be thick enough to hold pressures that don't get smaller just because you're trying to make a small sized rocket.
For example if you reduce the dimensions of a fuel tank by half and reduce the thickens of walls by half, tank will still have same mass fraction.
...strangequark:If you haven't already, I suggest you read armadillos update archives. They did quite a lot with H2O2.
Quote from: Oberon_Command on 03/29/2009 02:51 amDanny, if you or anyone else would like, I could port that code to C, C++, or Java, since some people might find it easier to read or use that way. I was thinking of doing that anyway, since I'm one of those who, despite having started with QB, finds C-like languages more readable, but it occurred to me that others might find such a translation useful...c might be useful to many out there. Lot is c code in the world today. By the way, you must be a really strange dude if you think c is inherently more readable than QB ;-)
Quote from: Danny Dot on 03/29/2009 03:16 amQuote from: Oberon_Command on 03/29/2009 02:51 amDanny, if you or anyone else would like, I could port that code to C, C++, or Java, since some people might find it easier to read or use that way. I was thinking of doing that anyway, since I'm one of those who, despite having started with QB, finds C-like languages more readable, but it occurred to me that others might find such a translation useful...c might be useful to many out there. Lot is c code in the world today. By the way, you must be a really strange dude if you think c is inherently more readable than QB ;-)And, if you don't object, I'll have a bash at putting it into Python.Any particular wishes concerning a licence to be attached? Otherwise I'll tag it as being GPL which will keep your name attached and prevent somebody rolling it into their commercial product yet allow others to make improvements.Rick
c might be useful to many out there. Lot is c code in the world today. By the way, you must be a really strange dude if you think c is inherently more readable than QB ;-)
Quote from: Danny Dot on 03/29/2009 03:16 amc might be useful to many out there. Lot is c code in the world today. By the way, you must be a really strange dude if you think c is inherently more readable than QB ;-)I never liked C, but then I never really used it beyond an intro course in college. Hate to say it, but I haven't really done any programming since my FORTRAN 77 days in school!
Quote from: vt_hokie on 03/31/2009 04:06 pmQuote from: Danny Dot on 03/29/2009 03:16 amc might be useful to many out there. Lot is c code in the world today. By the way, you must be a really strange dude if you think c is inherently more readable than QB ;-)I never liked C, but then I never really used it beyond an intro course in college. Hate to say it, but I haven't really done any programming since my FORTRAN 77 days in school! I saved my Fortran text for years, though what box it's in now... probably the same box as the Prolog, Pascal, and LISP books. I do most of my work with Visual Studio, these days, so that means C#, which is charitably described as "C-flavored."
Quote from: sbt on 03/30/2009 07:10 pmAnd, if you don't object, I'll have a bash at putting it into Python.Any particular wishes concerning a licence to be attached? Otherwise I'll tag it as being GPL which will keep your name attached and prevent somebody rolling it into their commercial product yet allow others to make improvements.RickThanks for asking. Sounds like a good idea. Is that what GNU does to their code?Danny Deger
And, if you don't object, I'll have a bash at putting it into Python.Any particular wishes concerning a licence to be attached? Otherwise I'll tag it as being GPL which will keep your name attached and prevent somebody rolling it into their commercial product yet allow others to make improvements.Rick
Are there any general guidelines for sizing diameter versus length for a cylindrical ELV with a given LEO payload capacity, specific impulse, and propellant density?Suppose you wish to launch a payload with a relatively large diameter for its mass. Would it be better to launch it in a fat PLF on a skinnier LV or to launch it on a relatively short and squat LV that matches the PLF?
In other words, is there a "golden aspect ratio" for earth-launched rockets, and to what extent does the diameter of the payload affect the optimal diameter of the rocket?
Quote from: William Barton on 03/31/2009 04:25 pmQuote from: vt_hokie on 03/31/2009 04:06 pmQuote from: Danny Dot on 03/29/2009 03:16 amc might be useful to many out there. Lot is c code in the world today. By the way, you must be a really strange dude if you think c is inherently more readable than QB ;-)I never liked C, but then I never really used it beyond an intro course in college. Hate to say it, but I haven't really done any programming since my FORTRAN 77 days in school! I saved my Fortran text for years, though what box it's in now... probably the same box as the Prolog, Pascal, and LISP books. I do most of my work with Visual Studio, these days, so that means C#, which is charitably described as "C-flavored." Oh - now I 'C'. (grin)You may find this a little strange, but I actually prefer VB. It's very conversational and sufficiently structured that I can do just about anything I want. Of course C is more powerful; it's just not as much fun. Plus most Macro applications for Window-based software is executed by VB. Makes it convenient to be conversant with it.