Engineering

I've been looking for a reason to put people at the bottom of the ocean and there aren't a lot of practical reasons. ROVs can do most or all of the work. But I think I finally found one reason that makes sense. Hydrogen is the best rocket fuel but not not long journeys because the tiny atom leaks from the tanks. However metallic Hydrogen will not have this problem. Metallic Hydrogen also seems to have a boost in efficiency by 4x but I don't understand how. However the diamond anvils needed to press Hydrogen into metal are at their limit, right at the limit apparently. So what if we put the diamond anvils at the bottom of the ocean? That will add some 1000at…

Injecting hydrogen in the divergent of an engine downstream dense propellants was experimented long ago. But if the dense propellants are pressure-fed, I claim one can build a (mainly) oxygen-hydrogen engine without pumps. This isn't normally done because hydrogen pressure tanks are too heavy. Figures are just examples to help understand and check. From pressure tanks, scalable 1kg/s oxygen is fed in the chamber and burns only 28g/s alkane at 80bar and 1056K. Expansion to 27.2bar converts half the enthalpy available in the hot gas, so the gas can't flow upstream, and it builds a vacuum downstream a sharp obstacle. There, hydrogen ducts end facing downstream, which su…

Why did SpaceX lie about this? This is a serious lie. Falcon Heavy only has 3.4million lbs of thrust. Orbiter had 6.78mil lbs of thrust. What is the purpose of this lie? SpaceX also lies about: 1) being first to have reusable rockets. All of Orbiter was reusable except a single fuel tank. 2) being first to have a reusable spacecraft. Orbiter was reusable. SpaceX also claims achievement in areas that are not achievements. 1) using Methane fuel. This goes backwards from Hydrogen technology. 2) being able to land a rocket. Apollo landed rockets on the Moon just fine. Earth rockets just fall into the sea to recover them.…

A number of my past posts relate to hypothetical alternative sources of electrical power. I'm wondering if it'd be more efficient (pun intended) to coalesce them all into one megathread, such that people could compare and contrast these hypothetical proposals. I'd like to reiterate all these proposals, and a few new ones: A. One common criticism of household solar panel rooftops is that they're vulnerable to hail damage. I'm not sure if there's some way to mitigate this vulnerability that the fossil fuel industry doesn't want us to know or whatever, but in the meantime, since thermal solar isn't as vulnerable to hail damage, would a better approach be to have …

In few years hydraulic fracturing has revolutionized the world of energy by the production of shale gas and shale oil. It is perhaps possible that fracking can reach another resource in the depth of the Earth: gold. A new theory established by geochemists (1) describes a transport of gold by trisulphide ion in hydrothermal deposit. Trisulphide ion chelates gold and facilitates its transport towards the ground surface by water. But the stability of trisulphide ion depends of temperature and pressure. Trisulphide ion decays at a depth of some kilometres and leaves a first deposit of gold. According to this theory, a second transport by chloride and sulphide ions e…

Look. Musk is NOT a genius. As a person intimately involved in his Gigafactory debacle: 1) his factory is STILL at 25% capacity. Panasonic rightly took over most of the slack making bank of Musks flaccid manhood. 2) lithium ion tech was ALWAYS a dead-end. It's still a dead end for the same reasons now...there's not enough of it and the Chinese own most of it. 3) Capital structure locks TESLA into a death spiral as technology moves away from Li-ion and other car companies move into hybrid solutions for EV vehicles. Why does this matter for SpaceX? 1) Dragon capsule is a spruced up Apollo/Soyuz design. Nothing new. Actually it adds a significant pro…

I would like to take the time to present an idea I have come up with. Please note that I am a layman when it comes to the field of rocketry so please keep this in mind My idea is " The usage of a ferromagnetic fluid, such as ferrofluid, as a replacement of conventional rocket fuel in order to develop a rocket engine which would have the potential of recycling its fuel continuously through the usage of motor pump technology. All the while containing both the rocket along with the fuel and other components of the engine inside of a casing so that the different fluids do not escape from there respective housings. (Here is a general image of the idea that I am …

I am studying electrical engineering again and have read that the electrons travel from the negative lead to the positive one at a very slow velocity. Now the book states that in order for the mechanism for voltage to work an electron accumulation or "build up" occurs at the negative lead and when a non-zero resistance in placed between the positive and negative leads an impulse of energy is sent through the conductor which connects the positive and negative ends of the battery. My question is, as seen from the title, if that pulse happens continuously then how fast are the electrons building up or accumulating at the negative end of the battery. What would this depe…

Hi, Sorry for this huge post. You've been warned For this to make any sense at all, i must first explain a bit why i'm thinking about room cooling and make a post in this forum. I'm living in an apartment in The Netherlands on the first floor. I have neighbors on my left, right and above. Below my apartment are storage rooms. The ceiling of those storage rooms (that would be my floor) are covered in hot water pipes. If you see my apartment as a rectangle then the two long sides are made of concrete, the walls between my apartment and my neighbors. The remaining sides are just the façades where there are windows with double layered glass. Of all the r…

Hello everybody! The gas generator cycle is widely used on rocket engines, but some variations are still possible and desireable. For instance, the Falcon launcher burns the derived flux with much kerosene and little oxygen to limit the turbine's temperature, but the resulting soot complicates the reuse of the engine. One alternative, similar to Ariane's Viking, would add water to a tuned mix of RP-1 and oxygen, injected in two steps. 107:10:34 results in 873K=600°C; expansion from 50bar to 5bar gives 1133m/s. Good solution with one pump more. If accepting additional propellants, (yuk!) hydrazine or MMH, hydrated for 600°C, give 2004m/s and 1696m/s - not fully …

Hey Everyone, newbie here. I'm aiming way over my head here, but was wondering about something has been bugging me all day. At 70000 feet ( 21km) passed the Armstrong Line fluids start to boil, due to the atmospheric pressure, producing steam and therefore energy. Now, its like -56C° at that altitude and possibly colder in the Mesosphere. Does Liquid Hydrogen create enough energy once it has reached the Boiling point of -252C°? Even though liquid hydrogen has low energy density, and has high specific energy. Could a plane with a fully pressurised cabin, something larger than a U2 jet, be powered by a Liquid Hydrogen steam powered engine/jet propul…

Hydrogen fuel cells would bring big advantages to helicopters. Fly long! Airborne 1t including passengers and fuel takes ~100kW with 78m2 rotor(s), say mean 130kW with the manoeuvres: that's two Honda Clarity fuel cells of <100kg each. 48kg hydrogen keep it in flight for 8h - that's 100kg with the tanks I described there http://www.scienceforums.net/topic/73798-quick-electric-machines/#entry738806 Electric motors save maintenance, expensive and long with gas turbines. Electric motors are easily spread among many rotors, leading naturally to quadtoror-like designs. This is way easier than the pitch of common helicopter blades, which changes over a turn. http://en.wi…

Online, it seems a lot of sources say LIDAR doesn't work as well as RADAR in rain or humid, dewy weather. Maybe it's obvious, but I was essentially just wondering why. Why does water in the air affect light waves more than radio waves?

We have a thread on comparing electric to heat engine powered vehicles, but this and a recent discussion elsewhere inspired me to consider passenger cabin heating in electric vehicles. IC engines have the advantage of a readily available heat source. Does anyone have any data or experience of how an electric car is heated and how much energy this takes ?

Driving Anger, a specific situation consisting of emotional structures of feelings and thoughts associated with anger produced during driving. I happened to know this definition by reading an article (Convolutional Neural Network and Bayesian Gaussian Process in Driving Anger Recognition) published in an open-access journal (Engineering, https://www.scirp.org/journal/eng). It is very interesting. Actually, I am not very familiar with the frontier technology to recognize driver anger and distinguish angry driving. Just interested in this saying "Driving Anger". Does anybody have the same experience when driving a car? What is your attitude towards Driving Anger?…

Hello you all! Many rocket engines pump liquid propellants to their combustion chamber, and varied cycles are used to power the pumps, the best known being: Gas generator http://en.wikipedia.org/wiki/Gas-generator_cycle_(rocket) Staged combustion http://en.wikipedia.org/wiki/Staged_combustion_cycle_(rocket) Expander http://en.wikipedia.org/wiki/Expander_cycle_(rocket) but here I'd like to describe uncommon cycles, which may be new and of my invention. ===================================================================== The first sketched cycle realizes the cracking (hydrogenolysis) in a pre-chamber of a hydrocarbon with hydrogen, which produces methane, some exc…

You've probably seen these (Falcon 9?) rocket landings before in news or on the net. When I think of the size of this thing and earth's gravity, I cannot fail to be impressed.. even though one explodes.

Hello everyone and everybody! Some rocket engines inject a small amount of a third propellant that ignites by contact with one main propellant. For instance the RD-170 and heirs start with the liquid oxygen and some triethylaluminium followed by the "kerosene". The RD-170 had little choice. Much liquid oxygen immediately quenches the many flames in its gas generator, demanding as many ignition sources, easier with the hypergolic pair. But triethylaluminium ignites upon air contact, as probably do all compounds igniting with liquid oxygen. That's badly dangerous near 500t of fuel and oxygen. I propose here to add two hypergolic propellants for engines whose …

The world energy consumption is some 150,000 TWh. The average solar irradiance at the surface level is 163 W/m^2. Assuming, quite arbitrarily, that we can harvest 10% of that by using the photovoltaics aka. solar cells, we can calculate how much solar panel would be needed to satisfy the world energy demand. The answer is 1.05 million square kilometres. While that sounds like a lot, it must be compared to the total surface area of the Earth, 510 million square kilometres. It may also be compared to the the area of the Australian desert, 1.37 million sq-km, or the area of the Saharan desert, 9.2 million sq-km. So, is the future solar? Isn't solar energy the silve…

Who would've thought that the inventions of Charles Babbage and Alexander Graham Bell would be merged and miniaturized. Now, if we could only do the same thing with the inventions of Henry T Ford and the Wright Brothers.

It is common knowledge that burning fossil fuels can be harmful to the environment. However, if we are going to burn fossil fuels I believe there are ways to do it that are less harmful. For instance, smoke stacks. With smoke stacks you don't have ground level pollutants. Ground level pollutants are more harmful than pollutants way up in the air which is why I believe factories are required to have them. However there are some machines that burn fossil fuels that will result in ground level pollutants the most obvious being cars and trucks. Other gas operated machinery such as lawnmowers, leaf blowers, tractors, etc, further contribute to the problem. As it is, they …

I have been researching the different kinds of food storage jars which reduce the amount of contact oxygen has with the contents of the jar, I found the a manual plunger style from Prepara to be the most simple, over their mechanical rivals, which use a levers or other intricate mechanisms. It's such a clever design, but since their launch demand has decreased to the point that they've begun thinning the glass containers, and now their slogan reads that only food safe BPA-free plastic touches the food (rather than only glass and food grade stainless steel), which I have a problem with, along with the prices and the fact that the one way valve mechanism cannot be deco…

Can we PRESERVE and HONOUR our DEAD ? Walker’s Casket ! For sometime I have been thinking about it and here is what I say : This is after viewing the agonizing Research by Archeologists in unearthing the past and I give below the links : It will be nice from now onwards if we can preserve and honour our dead as it should be and not leave it to chance to be counted in future. Of course many illustrious Personalities must be preserved in a much better way than ordinary folks and suitable monuments erected. We all live and STRIVE TO MAKE A MARK IN HISTORY but have to die on someday ! That FRAME OF…

I would appreciate some advice for a conceptual product. Which materials does snow not stick to or build up a significant amount?

I am curious on it