How plausible would this mecha be

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ryu289
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Joined: Mon Jan 20, 2020 1:17 am

How plausible would this mecha be

Post by ryu289 » Fri Apr 17, 2020 8:11 pm

During my research into possible real world technologies for potential mech design, I came across this:
Photon-intermediate direct energy conversion (PIDEC) is somewhat similar to a concept of fluorescent light - as in the CFL, in the nuclear reactor the original type of energy generated is not useful to humans. CFL uses a fluorescent coating on the inside of the light bulb to convert that energy into visible spectrum of the light. PIDEC uses fluorescer (in the form of gas) surrounding nuclear fuel acting as photon producer - fluorescer gets excited by neutron emissions and in turn emits narrow band ultraviolet light. That light is then relatively easily converted into electricity by special photo-voltaic converter.

Because the photons emitted by fluorescer are narrow band, the conversion efficiency is much higher than efficiency of common solar cells. The overall efficiency of PIDEC is expected to be around 40%. The remaining residual heat is still high enough to use it in traditional thermalized way via Carnot Cycle e.g. steam turbine. A combined efficiency of such conversion system (PIDEC + traditional) could reach as much as 70%. In comparison, due to limitations of using solid nuclear fuel and water as coolant, current generation of nuclear plants average only about 35% conversion efficiency.
Now as explained Here , PIDAC was conceived for use in high temperature fusion reactors

In addition, it is capable of also generating power from fission and radioisotopes

During my research into this concept I came across this study:
A two-step photon-intermediate technique for the production of electricity, chemicals or lasers in nuclear energy conversion

In addition to electric power, photolysis makes other product forms possible. These products include useful feedstock, or combustion chemicals, such as hydrogen and carbon monoxide, and excited molecular and atomic states, used for laser amplifiers or oscillators.
Interesting...I mention this as it reminds me of how Mark Simmons describes how Gundams and Zakus generate both power, propulsion, and even beam weaponry: http://www.ultimatemark.com/gundam/power.html
Since electrical generation, propulsion, and cooling all involve extracting thermal energy from the reactor and transferring it to other parts of the mobile suit's body, why not use the same mechanism for all three? The author imagines a network of thermal energy conduits running throughout the mobile suit's body, transferring reactor heat via high-pressure helium gas (8). This provides a handy explanation for the cables and tubes that decorate the exteriors of our favorite mobile suits (9).

The classic MS-06 Zaku II. In the author's opinion, its trademark power cables are most likely used to transfer thermal energy for propulsion, electrical generation, and cooling purposes. This theory is, however, at odds with the official explanation (10).
Here are his footnotes fyi:
(8) Entertainment Bible 1: One Year War Picture Encyclopedia identifies helium as the coolant used in the MS-06 Zaku II. Since this is also a suitable medium for transferring reactor heat to generator turbines, and its relatively low molecular weight makes it an efficient propellant for thermonuclear rocket engines, it seems like a good candidate for all three applications. Plus, this would explain the significance of the mysterious "helium control cores" attached to the Gundam's skirt armor!

(9) For example, the Master Grade GM Custom kit manual explains that the cables that run down the back of the mobile suit's legs supply energy to its leg thrusters.

(10) The official explanation for the Zaku II's cables is that they transmit hydraulic power to actuators in the mobile suit's joints. This always struck me as absurd, for why would the Zaku need to transmit hydraulic power from its belly to its backback, or from its muzzle to the back of its head? Likewise, early mobile suits like the Zaku II and the Gundam are usually said to use traditional chemical rocket engines, but this seems to defeat the purpose of having a thermonuclear reactor in the first place.
Now while Mark's explanation makes sense, it seems to me that PIDAC fulfils a very similar design.

For example a similar form of propulsion to Mobile Suits using PIDEC would be based on the "Nuclear Lightbulb" concept

As someone else put it: https://space.stackexchange.com/a/27372
The idea is that you operate a fission reactor in a gas (really plasma) phase inside a transparent pressure vessel. The fissionables might be mixed with a fluorescing compound. If you run the reactor hot enough, radiation (which scales with the fourth power of temperature) becomes the dominant mode of energy transfer, primarily in the form of UV light. You pass your reaction mass - likely hydrogen doped with something to improve its UV absorption - over the outside of the reactor vessel. It's heated by the UV, conceptually to much higher temperatures than possible with solid core NTRs.

The concept hinges on the reactor vessel being so perfectly transparent to UV radiation that you can pass gigawatts of UV light through it without it absorbing them and therefore heating and melting. Additionally you need to run a plasma-phase fission reaction inside it (good luck with your neutron economy) and somehow protect it from that ferociously hot and corrosive material.
I am pretty sure he isn't right about the reaction mass needing to be passed over the outside of the vessel. It's all internal. At least it hasn't come up in the official scientific documentation.

He also mentions heat would be a problem, but again thermal conversion is comparable with PIDEC.
Not to mention there seems to be a way around the radiation damage issue: https://www.sciencedirect.com/science/a ... 4317308564

Back to Mark's article
However, this doesn't account for all of the cables. Mobile suits also need to transmit beam energy, in the form of Minovsky particles, to their weapons. The Gundam's beam rifle and beam saber both contain energy capacitors, which store the high-energy Minovsky particles used to form their devastating beams. In the case of the beam rifle, electrical power from the mobile suit's generators is used to convert the stored Minovsky particles into massive, fast-moving mega particles prior to firing.
Interesting isn't it. Especially since PIDEC also seems to be very useful for the making of Nuclear-Pumped lasers under a similar principle: https://books.google.com/books?id=Hmn_C ... on&f=false (see p.107 of the ebook link for reference)

I do think that if we ever make fusion powered mecha, this would be the best option, especially with recent breakthroughs in photovoltaics: https://www.nature.com/articles/ncomms14962

Now that we have the power settled let's look at how the construction of the mecha and how this power is transferred.

To do so let's look at the F91 Gundam
Multiple Construction Armor (MCA) is a multifunctional structural material in which the functions of electronic equipment, such as circulatory and cooling systems, are incorporated into the MS’ armor layers, making more efficient use of the highly compact MS’ limited internal space. The technology for embedding electrical functions into a structural material is first established in U.C.0090s with the development of the Psycho-Frame. MCA is an application of this technology after further development; it uses special structural materials alongside heterogeneous crystallization coupling technology that uses I-Fields.
Interestingly this sounds like an updated version of the semi-monocoque concept used in Gundam. The armour is providing additional support for the mech by being an attached outer shell with internal support structure...in this case the internal supports contain functions of the electronics, reducing the necessary size by a bit.

Off course I feel this would only be scratching the surface of the potential for this technology.

Here is a good way of looking at it:
Embedded healing agents are simple and effective, but they do have a drawback: interrupting the structure of the material with capsules can actually weaken it, potentially increasing the risk of failure—which is the very problem we're trying to solve! Now the human body doesn't fix damage this way with makeshift repair materials waiting inside every bit of skin and bone in case we happen to cut ourselves or fall over. Instead, our body has an amazingly comprehensive vascular system (a network of blood vessels of different sizes) that transport blood and oxygen for energy and repair. If damage occurs, our blood system simply pumps extra resources to the places where they're needed, but only when they're needed.

Materials scientists have been trying to design self-healing materials that work the same way. Some have networks of extremely thin vascular tubes (around 100 microns thick—a little thicker than an average human hair) built into them that can pump healing agents (adhesives, or whatever else is needed) to the point of failure only when they need to do so. The tubes lead into pressurized reservoirs (think of syringes that are already pushed in slightly). When a failure occurs, the pressure is released at one end of the tube causing the healing agent to pump in to the place where it's needed. Although this method can seal cracks up to ten times the size that the microcapsule method can manage, it works more slowly because the repair material has further to travel; that could pose a problem if a crack is spreading faster than it's being repaired. But in something like a skyscraper or a bridge, where a failure might appear and creep (spread slowly) over months or years, a system of built-in repair tubes could certainly work well.

Most of us know shape memory materials through relatively trivial everyday applications such as eyeglasses, made from alloys like nitinol (nickel-titanium), that flex exactly back to shape when you bend and then release them. Usually, shape memory works in a more complex (and interesting) way than this (read all about it in our detailed article on shape memory); typically you need to heat (or otherwise supply energy to) a material to make it snap back to its original, preferred form. Self-healing shape-memory materials therefore need some sort of mechanism for delivering heat to the place where damage has occurred.

[/b]In practice, that might be an embedded network of fiber-optic cables similar to the vascular networks used in other self-healing materials except that, instead of pumping up a polymer or adhesive, these tubes are used to feed laser light and heat energy to the point of failure. That causes them to flip back into ("remember") their preferred shape, effectively reversing the damage. How do the tubes know where to deliver their light? If the material cracks, it also cracks the fiber-optic tubes embedded inside it so the laser light they carry leaks out directly at the point of failure.[/b] Although you might think fiber-optic tubes would weaken a material, they can actually strengthen it by turning it into a fiber-reinforced composite (effectively, they serve as the fibers you'd get in something like fiberglass, or like the steel "rebar" rods in reinforced concrete). Systems like this are sometimes known as autonomous adaptive structures and have been pioneered by materials engineer Henry Sodano.
Confused? Well please keep in mind how thing these "veins" are described as we look at how one very important piece of Mobile suit tech is described:
The joints of Zeon mobile suits are driven by a fluid pulse system, which used a pulse converter to turn the energy produced by the atomic reactor into pulses of pressure within a fluid. [/b]Thousands of fluid pipes, finer than human hairs, transmitted these pulses at supersonic speed to the rotary cylinders which drove the joints. This system yielded a higher operating speed than hydraulics, and lower weight and greater structural simplicity than electric motors.[/b] The exposed power cables seen on some Zeon mobile suits, such as the Zaku II series, are part of the fluid pulse system, connecting the reactor to each joint.
See what is bolded? Remember what I asked to keep in mind before? Granted while I think by the time of F91 mobile suits would be using something more advanced that nuclear-powered pulsed-power hydraulics, I do think a similiar system using energy pulses delivered from the reactor via fiber optics could be very viable.

A similiar system could also be used for sensors:
"If you want robots to work autonomously and to react safely to unexpected forces in everyday environments, you need robotic hands that have more sensors than is typical today," said Yong-Lae Park, assistant professor of robotics. "Human skin contains thousands of tactile sensory units only in the fingertip and a spider has hundreds of mechanoreceptors on each leg, but even a state-of-the-art humanoid such as NASA's Robonaut has only 42 sensors in its hand and wrist."

Adding conventional pressure or force sensors is problematic because wiring can be complicated, prone to breaking, and susceptible to interference from electric motors and other electromagnetic devices. But a single optical fiber can contain several sensors; all of the sensors in each of the fingers of the CMU hand are connected with four fibers, although, theoretically, a single fiber could do the job, Park said.

So Park, working with mechanical engineering students Celeste To from CMU and Tess Lee Hellebrekers from the University of Texas, invented a highly stretchable and flexible optical sensor, using a combination of commercially available silicone rubbers. These soft waveguides are lined with reflective gold; as the silicone is stretched, cracks develop in the reflective layer, allowing light to escape. By measuring the loss of light, the researchers are able to calculate strain or other deformations.
We can even use this to recreate Gundam Seed's Phase Shift Armor:
A new version of reactive armor is currently in development that uses electricity instead of explosives to disrupt anti-tank shells. The two plate system from standard reactive armor is retained but instead of explosives, the space is filled with air or an insulating material. This creates a capacitor which can store electrical energy. When a HEAT round penetrates the armor it connects the two charged plates, discharging the stored electricity. The electrical discharge disrupts the stream of liquid copper, rendering it ineffective.
Does all this make sense?

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