toysdream wrote:The regular Dom uses thermonuclear jet engines. See the Gundam Century description for details.
-- Mark
True, my mistake. If you don't mind, I'll just quote what is written in the Gundam Century about MS-09 Dom. Thanks.
Mark's Gundam Century wrote:Since hovercraft systems had severe weight restrictions, they needed to develop an engine more powerful than the standard fan-jet type. Their solution was a smaller, jet-style version of the nuclear thermal rocket engines used in space warships.
Technically, the nuclear thermal jet engine developed for the MS-09 Dom was a hybrid jet/rocket type using liquid hydrogen as its propellant. It was originally thought that a pure jet engine using only air for propellant would be more efficient, but since the thermonuclear reactor had a core temperature of almost 100,000 degrees C, it was estimated that the engine would be unable to draw in enough air to adequately absorb all this energy and would thus melt down. So instead, large quantities of liquid hydrogen propellant were circulated through the thermonuclear reactor, and converted into plasma with a temperature of about 10,000 degrees C. The air then absorbed kinetic energy from this medium and was emitted as a powerful jet.
toysdream wrote:The regular Dom uses thermonuclear jet engines. See the Gundam Century description for details.
-- Mark
True, my mistake. If you don't mind, I'll just quote what is written in the Gundam Century about MS-09 Dom. Thanks.
Mark's Gundam Century wrote:Since hovercraft systems had severe weight restrictions, they needed to develop an engine more powerful than the standard fan-jet type. Their solution was a smaller, jet-style version of the nuclear thermal rocket engines used in space warships.
Technically, the nuclear thermal jet engine developed for the MS-09 Dom was a hybrid jet/rocket type using liquid hydrogen as its propellant. It was originally thought that a pure jet engine using only air for propellant would be more efficient, but since the thermonuclear reactor had a core temperature of almost 100,000 degrees C, it was estimated that the engine would be unable to draw in enough air to adequately absorb all this energy and would thus melt down. So instead, large quantities of liquid hydrogen propellant were circulated through the thermonuclear reactor, and converted into plasma with a temperature of about 10,000 degrees C. The air then absorbed kinetic energy from this medium and was emitted as a powerful jet.
Thus back to the original question, ho effient is that on fuel?
If my memory serve, apparently the usual Dom can hover for about 9 hours. If you really want to know that bad, you should check Mark's Ultimate Gundam.
lans* wrote:If my memory serve, apparently the usual Dom can hover for about 9 hours. If you really want to know that bad, you should check Mark's Ultimate Gundam.
Close - it's five hours, according to Gundam Century. The specs from that book are now obsolete, along with their assumption that the Dom hovers by directing one gee of thrust downwards like a VTOL plane rather than by emulating a hovercraft, but the five-hour operating time still is still cited by recent books.
toysdream wrote:Close - it's five hours, according to Gundam Century. The specs from that book are now obsolete, along with their assumption that the Dom hovers by directing one gee of thrust downwards like a VTOL plane rather than by emulating a hovercraft, but the five-hour operating time still is still cited by recent books.
I'm not very well versed in hovercraft technology, but based on Newton's Laws, wouldn't the Dom still have to exert a constant force of *insert weight of Dom* on the ground to counteract the force of gravity, regardless of the technology involved? Also, how is the Dom's hovering currently described? Because it certainly looks like it relies more on vectored thrust than hovercraft, but I don't know what the underside of it's foot looks like.
For hovering and movement, Dom got 2 nozzels on the back pack, 3 nozzels in the rear skirt, 3 nozzels in each calf (6 altogether) and 3 on each foot. But I the backpack nozzels are more for movement.
So for hovering, there could be 15 nozzels. So as you can see from the arrangement, the down ward thrust is spread out. So it would still exert a down ward force of the weight of the Dom, but will not be concentrated just on the foot.
I agree it does look more vector thrust. There is no 'rubber foot skirt' to trap an air cushion. And vector thurst can create hovering effect, like the Harrier jump jet.
Gadget wrote:For hovering and movement, Dom got 2 nozzels on the back pack, 3 nozzels in the rear skirt, 3 nozzels in each calf (6 altogether) and 3 on each foot. But I the backpack nozzels are more for movement.
So for hovering, there could be 15 nozzels. So as you can see from the arrangement, the down ward thrust is spread out. So it would still exert a down ward force of the weight of the Dom, but will not be concentrated just on the foot.
But that's the Rick Dom, not to be confused with the MS-09 Dom, which is what I'm talking about. The Rick Dom was designed for space, so it wouldn't have the propulsion mechanisms we're talking about. Maybe the Dom has a similar thruster layout, I'm going to look around that site and see what I can find. *sigh* Curse you, Dom...
Edit: Guess that was easier than I thought... sorta. This does show what looks like hovercraft skirts on the bottom of the feet, but it doesn't show the purpose of the calf segment of the legs, at least not it the detail I was hoping for. But if the images are still true canon, it looks like it is hovercraft in the feet with vectored thrust from the leg that allows the Dom to hover around at the speeds it's famous for.
Areku wrote:I'm not very well versed in hovercraft technology, but based on Newton's Laws, wouldn't the Dom still have to exert a constant force of *insert weight of Dom* on the ground to counteract the force of gravity, regardless of the technology involved? Also, how is the Dom's hovering currently described? Because it certainly looks like it relies more on vectored thrust than hovercraft, but I don't know what the underside of it's foot looks like.
Well, in short...no. A somewhat significant amount of load would be held by an air cushion, so technically we'd be looking at that proportion of weight being exerted against said air. What you're looking at it is a high pressure zone underneath the Dom's feet, which it sits on top of (fundamentally, because the air pressure above it is lower-but it requires the addition of thrust to reach a hover state, since the force produced isn't enough). Don't ask about the aerodynamics of it, it's hard enough to get past the Zeta Gundam flying.
The Dom seems to have a two phase process in terms of movement the first stage is the lift the Dom creates enough force to create enough force from the ground to create "lift". After lift is achieved the resistance of the dom in relation to the ground is greatly reduced. The thrust generated by it's verniers enables it to move effortlessly across the ground. I guess depending on the terrain Doms could use a filter to prevent clogging of either it's jets.
jamnewman0056 wrote:The Dom seems to have a two phase process in terms of movement the first stage is the lift the Dom creates enough force to create enough force from the ground to create "lift". After lift is achieved the resistance of the dom in relation to the ground is greatly reduced. The thrust generated by it's verniers enables it to move effortlessly across the ground. I guess depending on the terrain Doms could use a filter to prevent clogging of either it's jets.
No offense, but seriously, you don't need to reply to every threads and every topics you know. Most of your posts only repeating what we already discussed in previous posts or just voicing over what we already know. Have you really read the previous post before jumping in?
Back to the topic, is it really true that the DOM also use vernier/ apogee motor as a source of driver method in earth environment? I thought it was the thermonuclear jet engines from the start till the end. I know Dom got their own twin vernier in the back torso, but IIRC it's only used for jumping purpose. Just like the standard Zaku and Gouf use their own verniers.
is it really true that the DOM also use vernier/ apogee motor as a source of driver method in earth environment? I thought it was the thermonuclear jet engines from the start till the end. I know Dom got their own twin vernier in the back torso, but IIRC it's only used for jumping purpose. Just like the standard Zaku and Gouf use their own verniers.
Indeed
The big arse rockets in the feet provide upward lift and the rockets in the calfs, arse and back provide the forward motion. But shifting weight distributon on the feet must also help in movement..i.e like a rollerblader/ ice skater : )
Sometimes the appropriate response to reality is to go insane - Philip k. Dick
lans* wrote:Back to the topic, is it really true that the DOM also use vernier/ apogee motor as a source of driver method in earth environment? I thought it was the thermonuclear jet engines from the start till the end. I know Dom got their own twin vernier in the back torso, but IIRC it's only used for jumping purpose. Just like the standard Zaku and Gouf use their own verniers.
Actually, jamnewman had it right. A lot of the published sources say that the original Dom uses the nuclear thermal jet engines in its feet for hovering, and conventional rocket engines in its skirt and back for forward motion.
toysdream wrote:Actually, jamnewman had it right. A lot of the published sources say that the original Dom uses the nuclear thermal jet engines in its feet for hovering, and conventional rocket engines in its skirt and back for forward motion.
-- Mark
Then apologize is in order for jamnewman for my rather rude post above. And it's corrected by Mark, apparently it's true then that Dom use it's conventional rocket to move back and fro, while the thermonuclear jet engines only provide air cushion for hovering. Glad we have you Mark to correct this things up.
No problem actually that hypothesis I got was from an article I read about the Harrier jet. I figured the legs were the cushion the skirt and back thruster add propulsion forward and when adjusted maneuver the MS. Most hover craft use flaps to change direction while inflating the bottom of the craft on water. This is kinda shaky due to the fact water has much less resistance than any terrain on earth.
Well, it looks like the debate on the Dom has been concluded, but I was planning on asking this later, might as well cover it here. What about possible alternatives to the Dom's nuclear thrusters?
If this is too off-topic, let me know and I will promptly remove this.
For simplicity's sake, let's assume we're looking at something that looks just like the Dom. Would it be feasible for the suit to hover without using hydrogen fuel? One solution may be to create forces similar to what it uses, namely by creating an air-cushion beneath the feet while providing vectored thrust through the calves, but rather than using special fuel, it does something else. I was thinking of it drawing in air in it's waist, and then compressing that air. The nuclear reactor could then divert a large amount of electricity into a special high-resistance circuit (in the shape of a large U-shaped plate), perhaps made of a conductive ceramic. This circuit would quickly reach an intense heat, and the compressed air would be funneled through this circuit. It would absorb the heat from the plate, and would reach high pressures even as it was pushed downward through the leg (the compressor would be just above the circuit, so that the air would be forced downward). As it neared the lower leg, the air could be diverted into either the air cushion or the calves, and the high-pressure hot air would generate sufficient thrust to allow the "Dom" to hover. The forward thrust would be arbitrary, just to focus on the hovering. Does this sound plausible, or is it merely wishful thinking? Any other ideas?
