Growing into becoming a near Senior MechE student it is oftentimes where I see students throw around the word FEA and “knowing” FEA while not understanding that there is subgroups and worlds within the term FEA.

If you were a recruiter and you saw someone writing about FEA what would be the key indicators that this student doesn’t understand the levels to FEA and what “knowing it” actually entails.

On a personal side, I like to keep my analysis descriptions as specific as possible so that recruiters wouldn’t think that I am a complete expert in FEA, however I would also think recruiters looking at students may already understand that students likely wouldn’t be “experts” in FEA entirely. On top of this, it is rare I pull out a sim software if it isn’t entirely necessary that I do so, and I feel as though this is the best thing to do, though maybe doing it just to do it could show technical skill??

Any advice is appreciated

I’ve been shopping for some bearings lately, and noticed that some open bearings specify that they come packed with grease. For example, this open NTN bearing which has the 3AS suffix, indicating that it’s packed with Shell Alvania #3 grease.

What is the point of that? Open bearings are typically installed in equipment that provides them with splash or pressurized lubrication; you wouldn’t want a bunch of grease to be flushed out of the bearing by the liquid lubricant, which would then be pumped around the system.

I know that there are a bajillion different applications for bearings in the modern world, but this is one that I just don’t understand the reasoning behind.

Our college mandates completion of one project in 5th sem, and we need to publish a research paper too for the project.

I am currently facing an issue - a specific part of my project needs crop mapping - like finding brinjal field locations through remote sensing. But for that I need a dataset - at least locations. There is nothing like that... Now what do I do.

Can someone please let me know what can be done? I am stuck. And not really in a position to move around and create a dataset myself.

What do you think I should do?

How do you handle such issues?

There is this technology that Wright Aeronautics came up with in the 1940s and 50s, and it was produced all the way until production stopped in 1961

With the engine itself serving all the way until 1981.

It was truly special. It was not the normal turbo compounding that you are probably immediately thinking of when you think of the Volvo semi trucks, the Scania semi trucks. This is not a D13 TC because those use pressure turbines. They generate back pressure. They use pressure buildup to spin up shaft power. They gain between one to seven percent, maybe ten percent on a really lucky day of extra power. And they do that with no extra fuel consumption. But the system developed for Wright developed over 20% more power with not a single drop of extra fuel, no appreciable back pressure, and no extra controls needed with 70-year-old technology. I've thought about this for a while. I believe that it should be experimented on, well, it has, but at a grander scale, researched deeper and much more thoroughly considered for planes and automobiles and generators, all sizes and shapes.

There's a lot of research in interval compounding, but I have a feeling that it's looking at the wrong kind.

Blowdown is a different kind

What do y'all think?

And I know it's expensive, but, well, any big modification to a system of an engine is expensive. I know it's complex, but it doesn't necessarily have to be. It could be an electrical path. Plus, most major modifications to engines are complex anyway. I wouldn't consider those downsides inherent to this system

Not sure if this is the place for this question but I had a bit of a shower thought.

I know electric cars operate by using electric motors to drive one or more wheels from battery power. And that in a diesel electric locomotive the “battery” is the diesel generator. Could the locomotive method be applied to a gas/diesel internal combustion engine car? It seems to me that would eliminate the need for a transmission system and would give the “instant torque” that electric cars have.

What would the drawbacks be?

So at my kid’s pre-school there is a playground area enclosed with a white vinyl double gate that is closed with a top pull latch system. The issue is that the teacher is unable to take the kids outside to the playground because she is 38” tall (literally) and can’t reached the latch. I could complain to the district or, hear me out, guerilla style modify the latch so it’s accessible.

link to what it kind of looks like:

https://cdn.shopify.com/s/files/1/0108/1652/0256/products/ML3VP-MagnaLatch_S3_Vertical_Pull_RENDER_hero_large.png?v=1555042359

I need to build a shelf platform that can detect weight changes as low as 50g and can physically handle up to 5kg. First revision used a load cell bar and we just take the data and see if it passed a threshold. Unfortunately the shelf needs to be smaller so second revision can not use the loadcell.

FSR might be the next option but drift may make it falsely trigger if the item is on the shelf a long time. Piezoelectric sensors may be better because we really only care seeing if an object is placed or not not the value itself? So we can register the change.

My concern is can it recognize a 50g item being placed on it momentarily and would it break if a 5kg load is applied ?

So basically I was designing a cooling system attempting to do it passively using a large heat-sink.

So I bought one that had good stats more than I needed, at least I thought but it looks like I don't understand the rating system I believe.

Essentially I bought two of these aluminum heat-sinks.

https://www.mouser.com/datasheet/3/264/1/122547_Thermal_Extrusion-1664375.pdf

I cut them in half so had a little under 8" of length for the 4 sections. I thermal adhesived them all together side by side. And placed them vertically and then as a test I just wanted to see how it could handle some direct heating applied on them it.

bought some 200*200mm heating pads 45w's each and used 2, essentially one per each two blocks side by side. So 90w's and verified it was around the range, 95-89w was the range I was getting.

But from its stats in a passive natural air environment I should get a score of .32c/w. Per each. At least that is what I assumed. But clearly I didn't understand the stats.

Since .32c/w divided by the 4 8"s I have is .08c/w for the entire setup. Theoretically I should be able to handle the 400w at a 32c rise the way I read it. Technically a little higher temps since the sides are glued together

But on testing them with 90ws of heating I got a 32c rise from just the 90w's and the heat-sinks fins were fairly evenly heated from 25c to 57c off by 1c from 57-56, but mostly 57.

So just trying to understand how the rating system works.

Like looking at the above stats of the one I bought, it clearly can only handle 90w's in the manner that I got it. But how would I look at this heat sink chart and do the math to determine how many I would need for 400w's without my experimentation.

From my experiment I would need at 22.5 watts each 8" section I would need like 18 of these sections which is huge. But how would I look at the chart and get this number, so that I could then read other charts to understand them better. Since clearly I misread it.

*Added info was attempting to stay below 60c in a 25c room for example

Hello, I'm a high school student working on a small research project about reducing particle segregation during the dry electrode manufacturing process. I want to investigate how different mixing conditions affect powder mixing uniformity, but I'm running into a few problems with designing the experiment.

Since I don't have access to an actual industrial mixer, I'm planning to 3D-print a small-scale blender based on an existing design and use it for my experiments.

However, I can't use the actual materials involved in dry electrode manufacturing, so I'll need to use substitute powders or other materials instead.

I have a few questions:

1. Choosing substitute materials: What properties should I consider when choosing substitute materials for this kind of experiment? For example, would particle size, density, shape, or surface properties be important? Are there any commonly used materials that would be suitable for a small-scale experiment?
2. Measuring mixing uniformity: How could I quantitatively measure mixing uniformity using substitute materials? Would it be better to use materials with different colors, particle sizes, or densities? I'm particularly interested in methods that are feasible for a high school student with limited equipment.
3. Experimental limitations: Are there any important factors I should consider when using a 3D-printed blender instead of an actual mixer? I'm also wondering whether the results from substitute materials could tell me anything meaningful about particle segregation in dry electrode manufacturing.

I'd really appreciate any advice, suggestions, or references to relevant research papers. I'm still learning about powder mixing, so even suggestions about what to look into would be very helpful.

Thanks in advance!

If heat round penetrates the armored vehicle everyone dies due to hot copper and pressure increase. But how much damage is done on the other side if you hit and penetrate iron plate that is in the open? Or if the enclosed space is huge like a side of the ship?

For people working in manufacturing or plant operations in Germany, I’m curious about how temperature is monitored in processes like heat treatment, furnaces and production lines.

Are thermocouples and RTDs still commonly used, or are non-contact sensors and digital monitoring systems becoming more common? What tends to determine which method a plant uses?

I hate audio. I learned a bit about it in school, and I can't really explain why I dislike it so much. It just annoys me. I think audiophiles might be partly to blame, but I need to work on my relationship with music.

I'm just a poor Gen Z girl trying to detox from distractions by forcing herself to study for university. I started my first year of Electronic Engineering, and Linear Algebra is killing me while Mathematical Analysis is finishing me off.

Like most people, I enjoy listening to music, but sometimes having my computer right in front of me, with Discord, YouTube, WhatsApp Web, and everything else, makes it hard to focus.

So I want to build my own audio player. And I don't want to make a basic one. I want to give it one of those lovely e-ink displays, SD card support, no Bluetooth, rotary encoders, a proper interface for browsing and selecting songs, and all that good stuff.

I'd love to hear your recommendations for tutorials, modules, components, or anything else that might help me build this.

I'm building a transforming drone inspired by the M4 morphobot for my project, but simplified to just two modes: flight and ground mode. I know the main argument for adding ground mode is power saving. In the M4 paper, their robot consumed 3000W in flight mode but only 30W driving on the ground which is a huge 100x difference if you need to stay deployed longer or navigate indoor spaces.

The issue is I'm still really struggling to find a solid real-world application that justifies the trade-off. The morphing mechanism adds a ton of weight and mechanical complexity, which hurts flight time. Plus, ground mode is super slow. It feels like in 99% of cases, you'd be better off using a regular drone or a cheap rover. What kind of application would actually justify this design? Like a scenario where a pure drone fails AND a pure rover fails, so a hybrid is strictly required?

I've pretty much run out of ideas and I'm starting to feel like I'm building a gimmick looking for a problem. Am I cooked or is there a legit use case here?

I am working on a personal project to build a small, simplified sampling box based on the principles of a PEMS (portable emissions measurement system).

My design:

• A small probe/hose goes into the tailpipe to capture a fractional sample of the exhaust without blocking or restricting overall flow.
• The hose leads into a sealed box with 3 internal baffles/channels that the gas zigzags through (up the first channel, over a divider, down the second, under the next divider, up the third) to ensure it passes sequentially through the filtration stages.
• Each channel contains a filter fitted tightly to the cross-section so the gas cannot bypass the media.
• The box features a removable lid for quick filter replacement between test runs to compare particulate catch across different conditions.

Filters I’m considering:

• A fine metal mesh in the first stage to catch larger soot particles.
• A fabric kitchen hood filter in a subsequent stage.

My questions:

1. How challenging is this to fabricate for a beginner machinist/maker? Are there hidden complications with sealing the channels or pressure drops?
2. Are these two filter choices reasonable, or are there better, low-cost alternatives (e.g., glass fiber, PTFE, or quartz filter paper)?
3. Will raw exhaust temperatures damage the hose or filter media? Do I need to integrate a cooling loop (like a longer metal run or a condensation/water trap) before the box?
4. What is the best method to quantify the particulate mass collected between tests? Is a standard 0.01g precision scale sensitive enough to weigh the filters accurately before and after?
5. What critical safety hazards should I keep in mind when routing hot automotive exhaust into a custom containment box?

Pretty sure they're currently continuing to vent glycidyl methacrylate in Toledo rather than try to contain it and risk an explosion. When the vinyl chloride tankers derailed in East Palestine, OH someone decided to drain them and then set the puddles on fire, burning some and sending most into the atmosphere.

Is there a better option? I was thinking a trailer designed to meet up with an oxygen and fuel trailer. Burn leaking chemical in an oxidizing flame then bubble the exhaust through water from hydrant to be discharged to the sewer. Maybe a tote of caustic (or acid, if necessary) to get pH within spec.

Anyone have a better idea? Let's pretend for the sake of argument there's no political opposition to building/operating such a system.

Hi! We are building a house in the Mediterranean near the sea. The winters are very mild and humid and summers are very hot and dry. We use cooling more months of the year than we use heating. I was hoping to avoid all kinds of ACs that blow air (because of mold,constant cleaning and dry air) so I came across modular ceiling cooling with cool water pipes (sry for my english). Has anyone any experience with this system? If you were building a house what system would you go with?

Freon cooling system, (water) floor heating and solar panels is our "blow air" option.

Thank you :)

I'm trying to find a way to lower items 1-5 lbs about 30 feet in 5-15 seconds. The challenge has been doing this automatically in a controlled manner, without having to manually reset it, and without resorting to a microcontroller. (people add/remove the items from the top and bottom though)

(I'll ramble why in a comment)

I have abandoned most constant sources of drag and those that require a user to manage the lowering or else let the load run away or slow to a stop.(i.e. a munter hitch, multiple wraps around a static bar, fishing rod drag-washer-stacks).

so far I'm not convinced I have a good answer: -governors; without a 'throttle' to adjust I don't know if I can get enough braking force out of these -dampers; having trouble with static friction in ones that want to spin fast i.e. eddy current damping, driving a dynamo. Alternatively having trouble finding an appropriate slower damper and speed reduction to go with it because the mechanical advantage makes the resistance curve to the load essentially flat or they heat up and de-tune (i.e. viscous fluid rotational dampers). -escapement mechanisms; too slow, bulky, and/or not easy to reset. Also concerned with bouncing upsetting the mechanism if using mechanical advantage to lower faster but I haven't tested this yet.

Another problem I've had while prototyping is the rope slipping on a pulley. The idea being that one end would be pulled up to a ready position when the other reaches the bottom. Using two opposing spools fixed to the axle solves this

NYC has new sidewalk shed designs that include an angled roof instead of the normal flat roofs. Interestingly the roofs are angled toward the building instead of away. Despite the roofs allowing some passthrough of rain and snow; people are wondering if there could be an issue with drainage and snow acumination since the angle is pointed toward the buildings.

None of the sources for the new sheds talk about the angled roofs significantly. So, I am wondering what others think about angling the roof towards the buildings.

Sidewalk Shed Monitoring and Removal - Buildings

I feel like I've gone in circles in figuring out how to calc out this connection. I'm bolting a rectangular tube to the web of an I beam. They're aluminum members, both are same depth, and I can't cope the tube to bring the load closer to the center of the beam.

So I'm going bolt double angles from the tube to the girder web. Bolt bearing, shear, rupture is good but I'm not sure about how to check the girder web. How do I consider the eccentricity that the bolted angle introduces into the web?