kaigou: this is what I do, darling (serious thoughts)
[personal profile] kaigou
For a takeoff using pure thrust and no wings, the thrust-weight ratio for the vehicle has to be more than one (for launch from the Earth's surface, for launch from the Moon it only needs to be more than 0.1654). In general, the thrust-to-weight ratio is numerically equal to the g-force that the vehicle can pull, provided the g-force exceeds local gravity then takeoff can occur. [Definition via Wikipedia.]

designation / nameseries or
country
length
(m)
wt, emp
(ton)
wt, gross
(ton)
thrust
(kN)
T/W
ratio
RX-78-2 GundamMSG18.543.460.0 0.93
RX-78GP01 Zephyranthes008318.539.765.0 1.66
RX-178 Mark IIZeta19.633.454.1 1.50
F91 GundamF9115.27.219.9 4.44
XXXG-00W0 Wing ZeroW16.78.0? ?
GT-9600 LeopardX16.88.5? ?
WD-M01 Turn-ATurn-A20.017.528.6 ?
GAT-X105 StrikeSEED17.7?64.8 ?
GN-001 Exia0018.357.2? ?
Typhoon F2UK 15.911.015.660.01.18
F-35 LightningUS15.411.720.1 0.89
F-22 RaptorUS18.914.325.1 1.26
F-20 TigersharkUS14.25.06.8 1.13
Kfir C-2 Israel15.67.310.452.9
MiG-23MLD Flogger-LUSSR16.79.515.7 0.88
F-89D ScorpionUS16.411.019.224.90.35
F-117 Night HawkUS20.013.423.8 0.40
B-2 SpiritUS20.971.7152.6 0.20


...In other words, I am such a frickin' geek.

Date: 6 Nov 2007 10:51 am (UTC)
From: [identity profile] penship.livejournal.com
*slaps forehead* I forgot about the GN particles. Wiki def: enables a gundam to fly without any apparent propulsion or exhaust besides sparkles of light... Okay, since T/W is a factor of total propulsion and it seems the sparklies GN particles don't really need propulsion besides the glittery shiny things, T/W is moot. Blah! This is what happens when you replace physics/aerodynamics with fangirl glitter.

Oh, and one last thing: how does Exia move so gracefully when it's so freaking heavy? Graham's Union Flag is even heavier (base weight: 67.1 tons) so I'm guessing the MS in this series will be heavy-set.

Date: 8 Nov 2007 08:44 pm (UTC)
From: [identity profile] kaigou.livejournal.com
I'm not entirely certain that propulsion no longer is an issue: if an object is going to move, it is either dragged, pushed, pulled, but in some way propelled. Even maglev trains -- which operate thanks to the repulsive power of two energized magnets, in simple terms -- still have rated/measureable propulsion (though I guess that'd be repulsion, technically?)...

My current theory about the overall weight of the mobile suits is that the designers are possibly riffing off the current theories/working knowledge of hybrid vehicles. A fighter jet carries a certain payload of armaments, but this is limited based on several things: the curb weight of the jet, the intended thrust-ratio (I've read of jets that got sent back to the drawing board when the t/w ratio, fully loaded, would end up lower unless weight got cut somewhere), and the weight of the fuel that has to be carried to allow the jet a specific range.

Now, the first problem is that currently our most common technology for engines is combustion, which requires fuel + oxygen + spark. We could run cars off batteries, but the drawback is that lacking combustion, the car would be like many electrical trains: sure, it'll get up to speed, but it doesn't have a lot of spunk. Those older battery-operated cars were so slow off the green light that drivers got frustrated and didn't want to have anything to do with them, and in a fighter jet (or mobile suit), you need explosive, abrupt, versatile power to maneuver in a dogfight. Natch.

Which means, I'd think, that any engine operating via stored batteries (which in and of themselves probably are a significant payload, possibly even heavier than fuel -- because as fuel burns up, the aircraft gets lighter, but batteries go empty but remain the same weight, which may even the t/w ratio throughout a flight, whereas conventional aircraft have t/w ratios that vary from starting/full to ending/empty) -- would be not only heavier due to batteries, but also heavier due to the additional engine adaptations required to modify an electrical engine so it can mimic the intense compression we get easily from a combustion engine.

Except that right now I should be dealing with painting the dining room ceiling instead of rambling on like this. Le sigh, I don' wanna... because OMG my brain is so happy when anyone makes a reply like yours. Don't mind me. This is my nirvana.

whois

kaigou: this is what I do, darling (Default)
锴 angry fishtrap 狗

to remember

"When you make the finding yourself— even if you're the last person on Earth to see the light— you'll never forget it." —Carl Sagan

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