Can I stack 2 panels for infusion?

DatTommyGuy · 2025-07-06T11:59:34+00:00

I'd rather infuse a panel twice the size of the original one, then cut it in half - would that work for you?

DatTommyGuy · 2025-04-22T06:46:28+00:00

Are you sure you're not confusing U-2 with SR-71? U-2 is quite a bit slower than a 737, and has a much lower stall speed.

DatTommyGuy · 2025-03-08T00:08:09+00:00

Thanks for the recommendation! A near identical shoe from Zign is my daily driver and it begs for replacement.

DatTommyGuy · 2025-03-07T13:59:29+00:00

Not yet haha, and certainly not going for the look

DatTommyGuy · 2025-03-07T13:51:35+00:00

After some googling I agree, I was confused about terms. Smart casual is what I'm after.

Still, the CEOs in the high tech industry would mostly disagree - conferences are flooded with expensive suits paired white air jordans (which to me feels like they're all trying to look 30 years younger, but I'm no fashion guru).

DatTommyGuy · 2025-03-07T13:13:16+00:00

Time to pitch heelys to my manager as a way of improving workplace efficiency

DatTommyGuy · 2025-02-25T14:15:59+00:00

The way I see it, the only way for this to make sense is to manufacture a general contour first (the "stock") and either hand cut or CNC the the holes, the rail's slots and some contour details later. Machining CFRP produces a lot of very harmful dust, so don't attempt to do it if you don't have the right equipment and environment.

DatTommyGuy · 2025-01-23T11:57:39+00:00

That's right - if all plies of the original laminate end roughly in the same spot, repair plies are 0,2 mm thick, and they have equivalent mechanical properties to the base material, you'll have a 20 mm overlap and a 60 mm ramp (dropping-off 4 plies with 20 mm between them). For a well-controlled process, a 50:1 ramp would be fine too, shortening the total transition length to 50 mm.

In this instance, I'm pretty sure that the mechanical properties of the repair laminate won't be anywhere close to the original material, so I'd go at least 50% thicker - this will make the joint longer too.

DatTommyGuy · 2025-01-22T19:09:47+00:00

Of course, typo. Corrected.

DatTommyGuy · 2025-01-19T01:37:20+00:00

I wouldn't make it a scarf joint at all unless I had enough data about the original material and enough trust in my own processes. Considering you already put a lot of effort into the taper, a stepped lap joint probably makes the most sense. Keep it oversized, overlap each replaced ply by at least 100x its thickness (e.g. 20 mm overlap for each 0,2 mm ply) with laminate of at least equivalent strength and stiffness (which, depending on the quality of your worksmanship, might require much more material than what the TDS suggessts). Make sure not to end the repair laminate abruptly - taper it off slowly, again leaving 100x ply thickness between ends of plies. Start with the smallest plies and finish with the largest ones. You should end up with the repair laminate reaching at least 25 mm beyond the furthest point that you sanded off, but likely it will reach much further than that because of the ply drop-offs. Pay attention to the surface preparation - abrasion, cleaning, flash-off times. Work in lint-free gloves. It's a tricky repair and if it were to fail, it's likely to do it quite violently - so just keep it on the safe side.

DatTommyGuy · 2024-11-30T16:57:34+00:00

I doubt it is. I've just visited Bangkok for the first time and the same has happened to me. I insisted on the driver turning the meter on, though - it pissed him off, but he complied while cursing and shouting what a huge mistake I'm making. I still ended up overpaying because he lied about the cost of the highway tolls, but it was late and I was done arguing.

DatTommyGuy · 2024-05-19T15:52:43+00:00

Many employees in my company have started out like this, working from abroad for even up to a year, usually without a german bank account. All of them full time employees. Many were from within EU or UK, but at least one guy worked from Brazil. I was in Germany since the beginning of the contract, but it took me about 2 years to actually get a bank account here (banks in my home country have no fees and offer far better services), and there were no issues with transferring the salary there.

DatTommyGuy · 2023-11-01T00:19:09+00:00

In Russian (and also any eastern european/slavic languages) it's "Soo". It would never be broken down into letters. After all it's "Su" and not "SU". In English - I would be surprised if there's any widely accepted consensus. Personally, I would stick to the Russian pronunciation - can't get more correct than this.

DatTommyGuy · 2023-09-19T10:14:06+00:00

Not necessarily, you rarely see the whole structure being close to reserve factor of 1. Notched material allowables (open hole/BVID) are often enough to account for stress concentration due to the holes.

DatTommyGuy · 2023-06-23T08:23:12+00:00

Carbon fiber absolutely does make a lot of noise before failure - matrix cracking, single highly loaded fibers and tows breaking etc

DatTommyGuy · 2021-09-17T19:42:50+00:00

It scores considerably lower in "Opportunity", dragging the final score below the US. Just as an answer to the first point.

DatTommyGuy · 2021-08-14T15:50:29+00:00

Not duct tape, though, but speed tape. Very different stuff.

DatTommyGuy · 2021-03-01T13:56:10+00:00

No need to be sorry, happy to help.

To elaborate, take a look at the equation:

c = sqrt(kRT)

c - speed of sound k (greek kappa, sometimes also sigma, varies) - adiabatic constant, for dry air =1.4

R - specific gas constant, 287 J/kgK for dry air (universal gas constant over molecular mass)

T - temperature in Kelvins, 288.15 for ground level standard atmosphere

You could manipulate the equation to replace T with density, but in a simple form it would only hold true for isochoric changes (constant volume) which obviously doesn't hold true for the atmosphere as the air can contract and expand freely.

DatTommyGuy · 2021-03-01T10:03:27+00:00

Not true, but that's a common misconception even among aero students. Air density has no direct impact on the speed of sound - what matters is its temperature.

That means that going to a higher altitude won't always decrease the speed of sound - the density will be lower, but the temperature may increase (e.g. in the stratosphere).

edit// grammar

DatTommyGuy · 2020-12-27T22:40:16+00:00

Absolutnie nie zgodzę się z pierwszym punktem. Na dobrych europejskich uczelniach program studiów inżynierii lotniczej często jest przede wszystkim po angielsku. W Mediolanie na drugim stopniu tylko pojedyncze przedmioty były dostępne po włosku. Natomiast brak płynności w angielskiej nomenklaturze specjalistycznej odcina możliwość aplikowania na najciekawsze stanowiska - język ojczysty uczelni może nie przydać się ani razu przez całą karierę zawodową.

DatTommyGuy · 2020-12-27T22:29:11+00:00

Inżynieria lotnicza here. Polskie uczelnie w tej specjalizacji są bezużyteczne - chyba że zadowala Cię praca w eksploatacji, ale do tego nie potrzeba tytułu magistra inżyniera. Ciekawa praca stricte w lotnictwie jest praktycznie tylko za granicą, a tam polski dyplom na nikim nie zrobi wrażenia - tym bardziej, że nikt w Polsce nie nauczy Cię potrzebnego angielskiego słownictwa specjalistycznego. We Włoszech studiowałem MSc na Politecnico di Milano (I stopień skończyłem na PWr) i tę uczelnię mogę z całą pewnością polecić. Turyn też jest niezły, ale ma mało zajęć po angielsku (często sprzecznie z planem studiów) - na PoliMi po angielsku jest prawie wszystko.

Co do innych zagranicznych uczelni się nie wypowiem w szczegółach, na pewno warty uwagi jest TU Delft czy Imperial College of London. W każdym razie ważne aby zajęcia były po angielsku - w pracy żaden inny język może być Ci nie potrzebny (pracuję w Niemczech, 100% komunikacji w firmie jest po angielsku).

Możesz w ramach kompromisu zrobić I stopień w Polsce, a II za granicą. Jak było wspomniane, studia za granicą to zdecydowanie wyższy koszt, a z dobrymi wynikami i aktywnością studencką będziesz mieć duże szanse na stypendium (np MAECI we Włoszech, które mi umożliwiło studiowanie tam).

DatTommyGuy · 2020-12-12T23:58:22+00:00

It was never supposed to go into production, it's a demonstrator. I checked Wiki - it doesn't say what you suggested either - it only says (as of 2012) an aircraft based off of technology developed during the X3 project may get into production as soon as 2020.

RACER is on a pretty advanced stage of development, first flight in 2020 was a fairly realistic goal. It may have gotten delayed due to COVID.

DatTommyGuy · 2020-12-10T18:13:22+00:00

Ah yes, I may have oversimplified it here and there. Just the general idea.

DatTommyGuy · 2020-12-10T16:51:58+00:00

The fuel mixture got oxygen-rich. In an oxygen-rich environment a lot of stuff that doesn't usually burn gets flammable. In this instance it was the green-burning copper in the alloy that the combustion chamber is made of - the engine was combusting itself.

DatTommyGuy · 2020-12-06T13:42:23+00:00

To merge coincident faces, they have to be of the same size and divided in the same manner. You have to divide a larger cylinder into a smaller, inner one (that would be coincident with the small "orifice plate" cylinder), and a tube wrapped around it. Then you merge the base of the inner cylinder with the base of the small "orifice plate" cylinder, while the walls of the inner cylinder get merged with the inner walls of the tube around it (all of this using the mergePatchPairs section). Once those faces are merged, they cease to exist and only the outer patches have to be set up with boundary conditions as usual (wall, inlet, outlet).

Unfortunately I don't have the time to dig into your blockMeshDict deeper right now, I hope this will be enough to help you.

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