Engineering

Found this pretty cool. Thought some here might react similarly. “Boeing engineers’ handmade airplane shatters a record by flying nearly the length of an American football field. <…> Their design was inspired by hypersonic aerospace vehicles and they practiced for four months before making their attempt. <…> “We tried to mimic the design of various hypersonic vehicles, which travel at speeds over Mach 5 (five times the speed of sound). So, we decided to call our plane Mach 5,” Ruble said. <…> Ruble and Jensen studied origami and aerodynamics for months, putting in 400 to 500 hours of creating different prototypes to try to…

If LED media can be made flexible, I visualized it could be used as reactive camouflage material. If one put led screen material on the underside of the plane and a camera pointing upwards towards the sky, it could relay the camera scene to the underside of the plane, more closely matching the sky in real-time. Plausible? Drones would be an easier first application, I think.

I don't mean the 'perfect ideal' Carnot of theory lessons. I just mean one that uses isentropic and isothermal phases. Like an Otto engine uses 2x isentropic/isochoric, and Stirling uses 2x isochoric/isothermal, so why are there so few examples, if any(?) of a 2x isentropic/isothermal machine?

Waste electrical and electronic equipment (better known by its unfortunate acronym, Weee) is the fastest-growing waste stream in the world. Electronic waste amounted to 53.6m tonnes in 2019, a figure growing at about 2% a year. Consider: in 2021, tech companies sold an estimated 1.43bn smartphones, 341m computers, 210m TVs and 548m pairs of headphones. And that’s ignoring the millions of consoles, sex toys, electric scooters and other battery-powered devices we buy every year. Most are not disposed of but live on in perpetuity, tucked away, forgotten, like the old iPhones and headphones in my kitchen drawer, kept “just in case”. As the head of MusicMagpie, a UK secondhand…

I've recently seen 'ABB' mentioned in hand tools and washing machines, being automatic ball balancers apparently consisting of ball bearings in a race track with some damping fluid. Do these only 'damp' the imbalance? I guess as the shaft experiences cyclic angular accelerations and decelerations then it'd damp those, is that it? So not really balancing the shaft masses by shifting CoG? Are there any passive shaft balancers that can shift the CoG to balance rotary motion of unbalanced shaft masses?

The Damage to Lunar Orbiting Spacecraft Caused by the Ejecta of Lunar Landers I am posting this here as it seems more of an engineering issue, so I found a paper posted to the Fediverse, looking at the problem of ejecta from the moon when spacecraft blast off from the surface and the potential damage this could do to any orbiting spacecraft. The paper can be found on arXiv https://arxiv.org/abs/2305.12234 Would i be right in thinking that this sort of thing is harder to physically simulate on Earth, even if we had a room where the floor is covered in a layer of moon dust (the fact the moon dust is not very pleasant or safe anyway) as we can't easily s…

Hello all. It works, satisfactorily, but the engine seems running roughly, and decided to investigate. The way it works is with a thermal choke fully applied when cold (bimetal spiral) heated by the exhaust opening the choke gradually. That operates fine from cold to hot, fully closed butterfly to fully open in a couple of minutes. No manual choke, no priming bulb, no manual speed control. But noticed than in the middle of the transition, there is a point where the choke butterfly wildly and widely closes and opens, like synchronized to every air intake pulse, like actuated by the air flow and not by the thermal bimetal. Looking at clues from web for…

Has there been any real breakthroughs in solar cell technology in the past years as far as electrical output per millimeter?

How do metal detectors work since they can detect metals that are not magnetic?

There are a place installed eclipse shape of mirror to reflect the sunlight to the area that is not enough sunlight in the town. In this case, they installed 51 square meter mirror and provide the sunlight to the area of 600 square meter with the mirror located 450 meter above the town. Can I know what is the formula to calculate the area of sunlight reflection? https://www.visitnorway.com/listings/the-giant-sun-mirrors-in-rjukan/3632/

Hello, An Engineer I know determined wind loads for a small but rather odd shaped structure assembled from various standard steel sections. It's a frame attached to the topside of a stadium roof to suspend speakers. We have AS/NZS 1170.2 (Australian) Wind Code, which gives detailed tables to calculate drag co-efficient’s for standard members. But my problem is this; Even if the sum of all areas and co-efficient’s were calculated, the wind loading (on any given face) would be incorrect, or very conservative! Due to the standard only applying to individual members. *Wouldn’t be easier to use a CFD package to model the wind loading, the …

Perhaps we can design a device that combines temperature sensors with pyrotechnic components. When the temperature sensor senses a change in temperature, it will send a detonation signal to the electronic detonators that make up the initiating component, and then the electronic detonators will detonate. How can this process be achieved?

Hello you all! Here's a means to produce a sine wave voltage, very pure, with metrologic amplitude, whose frequency can be varied over 2+ octaves in the audio range - this combination may serve from time to time. It uses sums of square waves with accurate shape and timeshift. A perfectly symmetric square wave has no even harmonics. Adding two squares shifted by T/6 suppresses all 3N hamonics as the delay puts them in opposition; this makes the waveform well-known for power electronics. Two of these waveforms can be added with T/10 shift to suppress all 5N harmonics, then two of the latter with T/14 shift, and so on. A filter removes the higher harmonics as neede…

Hello all. Noticed red vehicles and items fading their color coatings and rust surfacing earlier than in other colored coatings. Which metal roofing color should last longer from showing corrosion -for equal paints composition- ? -Image borrowed from web-

Hi all, I'm mixing two fluids, and want to find when they become homogenous. I'm using a mixing programme called Ansys, and I'm checking the mixing via the molecular viscosity. It gives this kind of result (this is after 2550 s of mixing): In this mix, I have the initial viscosities of the fluids set at 100 cSt (99 % of mix) and 500 cSt (1 % of mix) respectively. I'm mixing 60-180 s per step, until I'm at homogenous viscosity (so I can see at what time this occurs). Is this OK for finding the general homogeneity of the fluid? Here is the initial mix after 300 s, for interest:

There is many toy size / hobby size ones; am looking for something the size of a fist; used in whatever bevel geared mechanism, automotive, gardening, household appliances or any canibalizable from junk yard. Please suggest what could be a donor to salvage a similar one from. These are hobby/tool size, images borrowed from the web :

Hi all, Looking to measure some magnetic waves being generated at an electric coil. My pulse rise time is as fast at 50us and magnitude is pretty small <1T. Anyone have suggestions for the best tool to measure and log data of this magnetic waveform? Googling around, I found meters like this: url deleted I thought maybe even a simple hall sensor but not sure how to integrate it. What do you suggest? Thanks!

Tell me if there are very small emitters of microwave waves? Microwave emitters the size of a pea grain, for example? Although it is possible and more if there are no such small ones. Do they exist or can they be made?

I need two examples of a lifecycle assessment for an industrial park and two examples of carbon footprint assessments for an industrial park. If I can't find examples of a lifecycle assessment for industrial parks, I'll look for lifecycle assessments of factories in the footwear, food, or beverage industries. Please Keep an eye out for key sources of GHG gases produced by factories in these sectors

Hi all, I have a mixing simulation drawn up on the programme Ansys, where I am mixing two fluids. I want to verify my mixing process, by using this process to mix two other materials and take a variable of each material (e.g. viscosity) and compare the actual final mixing value to the one that I get when I mix them in my simulaiton. Is there a paper, site, or other available resource that contains mixing data for any two fluids?

A water tunnel in the lab I work in was designed poorly, and will require the implementation of some sort of wave absorber to eliminate waves disturbing the test section. The tunnel has a very short diverging section (downstream of test section) and afterwards redirects the flow 90 degrees downwards with a vertical wall. The tunnel is used for flow visualization and Particle Image Velocimetry. Has anyone dealt with a similar or relevant issue? Does anyone know of some resources I can look at? Where would you look to find literature or examples on this issue? Thank you -Ben

Are spent fuel rods cooling pools discharging radioactive water (tritium) into the environment? Since the spent fuel rods can still meltdown after 10 years in the cooling pools if the water is removed. “They point to a 2003 research paper that was coauthored by Macfarlane when she was a Massachusetts Institute of Technology researcher. That paper warned that if the cooling water were to leak out of a damaged storage pool, a fire would result, causing radioactivity to be released that could rival that from the 1986 Chernobyl disaster in Ukraine.” (J. Johnson). --------------------------------------------------------------- “Ten years after remo…

September 11, 2001 The South Tower Floor 85 "Come, Swansont!" I hollered, and Swansont and I leapt towards the open window. "Not so fast, young man," said Swansont quietly. Even over the screams, the din, his voice was as audible as though it were a lecture hall. "When you jump, keep pressed to the walls of the Tower," he said. "The walls of the tower?" I didn't understand. "Leap from ledge to ledge!" he said, and showed me. I watched, bemused, as Swansont took the first window ledge in it's stride. He leapt from the WTC window, and came to a halt a few metres below. His fingers had gripped the top of the window ledge just b…

Hello, I'm currently doing 3D mixing in a computer programme called Ansys. I have a cylinder full of water, featuring a square cuboid of calcium (the rectaungular cuboid is a stirrer bar, and the smaller cylinder is a mixing zone. I have gravity defined as the standard 9.81 m/s2 downwards) : I have the mixing set at 60 rpm at the moment. I find that, after 2.5 minutes, my calcium is down around the bottom (this is a volume fraction graphic, with more blue meaning higher fraction of water, and as the colour leans into red, you have more calcium) : Then, as the mixing continues, the homogeneity of the…

Maybe this is better in Climate Science? But engineering is what people DO to address human problems. About all humans can do to control anything about a volcano is to divert lava flows. But what if we could get a volcano to erupt on demand? Or kept erupting to deliver enough dust to the atmosphere to cool the earth enough to stall global warming? The big island of Hawaii has a volcano called Mona Loa erupting. Could it be used to deliver dust to the atmosphere, if the winds are blowing east the dust would get into the atmosphere before falling on the western US. Is there anything we could throw into the volcano that would help? "Climate scientists bring…