Ask a PhD candidate in aerospace engineering anything

[OP !jyyGvyuDkk No.4353002]

It's that time again. Questions about grad school, computational physics, and functional alcoholism welcome.

Questions about things you read a wiki page on are discouraged.

[Anonymous No.4353008]

How did you make it through the fluid mechanics courses? I am an AeroE student and just picked up my first course on it, so far we are being bombed with equations in integral and differential form. What strategy did you follow? any upstanding textbooks? I got Landau and Lifshitz course and its not bad

[Anonymous No.4353007]

How do you justify the risks of manned spaceflight?

[NavalAnon !!jz5JQZ1dN2Q No.4353016]

>>4353002
What is your favorite post 12-14 hour day drink.

Also, what sort of computing do you actually do on a daily basis, and do you observe any major operations/evolution while in your training?

[Anonymous No.4353019]

Can a fish into space?

[OP !jyyGvyuDkk No.4353021]

>>4353008
>How did you make it through the fluid mechanics courses?

My specialty! In the first course, it was pretty clear what we were expected to know: superposition of potential flows, basic conservation equations, basic relevant vector calculus (Reynolds transport, etc.)

It depends on the perspective of your prof what text is best for your course (I mean this in terms of only being interested in grades, not necessarily best possible understanding of the material.) I personally had an aerodynamics-centric course, and we used Anderson's fund. of aerodynamics. It's a lot more application-oriented than Landau & Lifshitz. As far as a modern textbook goes, Kundu/Cohen's Fluid Mechanics is probably the best single source (although very weak in applied aero).

In more classic books, Liepmann & Roshko for compressible, White's Viscous Flow, and I haven't seen a "good" turbulence book.

If you give me a sample exam type question you'd face, I can probably gauge your prof's style and give you a better reference.

[Anonymous No.4353022]

Does the 'aerospace engineering' allow you to do cool, pop-sci-esque shit, or you just crunch numbers and equations all day if the field?

[OP !jyyGvyuDkk No.4353025]

>>4353016
>What is your favorite post 12-14 hour day drink.
Strong, flavorful microbrews. I've also been on a bourbon kick lately.

>what sort of computing do you actually do on a daily basis
Computational fluid dynamics. Numerical solutions to Navier Stokes with big ole computers.

> do you observe any major operations/evolution while in your training?
what? we see some interesting shapes come out of optimization routines, but otherwise these things are pretty rigid by nature.

[OP !jyyGvyuDkk No.4353031]

>>4353022
>Does the 'aerospace engineering' allow you to do cool, pop-sci-esque shit, or you just crunch numbers and equations all day if the field?

Haha. Mostly the latter. Researchers tend to not be that interested in pop-sci, but I'd say I am pretty versatile. It depends entirely on the person and their interests outside of what they do day-to-day. I like to make cool MAVs, for example, but it's only tangentially related to my research.

[OP !jyyGvyuDkk No.4353033]

>>4353007
>How do you justify the risks of manned spaceflight?
Ask Neil DeGrasse Tyson.

He made a great explanation that risks have to be balanced by reward. Regular space shuttle access at low earth orbit is risky, but not very exciting or interesting. Manned flight to Mars? Still risky, but way the fuck more awesome, so it's easier to get behind the risk.

He also pointed out the legions of talented, qualified, sane people that would sign on for a one-way trip to Mars. I'd be in line.

[Anonymous No.4353039]

Am I appropriately dressed and equipped for manned space exploration?

[NavalAnon !!jz5JQZ1dN2Q No.4353040]

>>4353025

Sorry, navyspeak, I mean do you watch over any major ..programs, like a flight test, or a important new simulation, that sort of thing.

[Anonymous No.4353041]

>>4353021

Basic shit I guess, later we have more courses on it and aerodynamics. The program for this one is about ideal fluids, kinematics (pathlines, streamlines...), unidirectional motion, intro to viscosity, fluid statics, charge and discharge of tanks, and in the end intro to turbulence.

[OP !jyyGvyuDkk No.4353051]

>>4353040
Ah, "observe." I have a particularly unique role/field in that practically all my work is just myself and my PhD adviser. Most people are part of a larger group and are somewhat subservient, but I have a ton of autonomy. So I'm not in charge of anything you'd probably call "major" or "important," but I do run pretty large, unique simulations. I can't really be specific, as it'd de-anon me pretty fast.

[OP !jyyGvyuDkk No.4353055]

>>4353040
Hazarding a guess you're at the Naval Academy? Very solid people there.

[NavalAnon !!jz5JQZ1dN2Q No.4353060]

>>4353002
I love my academy bros to death, but I'm not one of them, I'm in magical nuclear land in South Carolina, and that already makes it semi easy to find me if you know ME.

[OP !jyyGvyuDkk No.4353070]

>>4353041
Gotcha, Landau/Lifshitz stuff... I wouldn't give to engineers, personally... it's more for physicists. And I mean that in the "LOL physicists are hilariously bad at fluid mechanics" way.

How I'd advise someone to study that's finding the undergrad coursework difficult that wants a better grade is different from how I'd advise someone trying to get a graduate level understanding. Though Landau/Lifshitz is kind of hardcore for a first course, so you might be at a pretty rigorous institution... so check out Kundu/Cohen if you need a supplement. And Sabersky et al has the best collection of fundamental fluids problems for you to practice.

[Anonymous No.4353071]

>>4353060
Your soul is mine!

[OP !jyyGvyuDkk No.4353072]

>>4353060
Yeah, I know the place, good on you. Feel free to leave a dummy email if you wanna chat off sci.

[Anonymous No.4353080]

>>4353070

Thanks, i'll look up those

[OP !jyyGvyuDkk No.4354071]

Bump, because why not. I'm bored.

[Anonymous No.4354103]

>>4353002

What are your opinions on project Orion? Do you think it was a good idea or that it deserved to get shut down?

[Anonymous No.4354126]

-Do you do a lot of manual mesh work?

-How much model (analytical) building do you do, i.e. do you improve on the equations (while understanding the physics you change) that you feed your computer?

-Do you work with compressible or incompressible fluids?

-Why is the Mach number such a relevant quantity. Can you explain it?

-Do you know a good book/reference for the limit from the full Boltzmann-equation descrption of gases down to conventional fluid dynamics?

-Are you familiar with plasma instabilities?

-Are all people at your working place as intolerant to several other fields of study?

[Anonymous No.4354135]

Did you happen to see that thread a few months ago about the guy who wanted to try to send a small rocket into orbit? Do you think it's possible for a one or two man team to put something into orbit on a hobbyist budget?

[Anonymous No.4354151]

It would be awesome if OP could write about his eduaction and what he does on my homepage.
I'm planning to become an astronautical engineer, so i guess this would help me a lot! :)

www.yurippe.net

See you there folks! I also want to get in contact with you OP over Email/yurippe.net

Also: Sorry for being a faggot

[Anonymous No.4354153]

>>4354135
video related
http://www.youtube.com/watch?v=y6ZMscMp8UM

[OP !jyyGvyuDkk No.4354218]

>>4354126
Crap, chrome plugin ate my post.
>Do you do a lot of manual mesh work?
Yes, depends what you mean by "manual," but I use Pointwise.

>How much model (analytical) building do you do, i.e. do you improve on the equations (while understanding the physics you change) that you feed your computer?
Improving the numerical methods is a matter of very active research, so it's not something you can modify on a daily basis. I do research in this, yes, but it's low turnover. I do change physical geometries all the time as part of optimization.

>Do you work with compressible or incompressible fluids?
Both.

[OP !jyyGvyuDkk No.4354228]

>>4354126
>Why is the Mach number such a relevant quantity. Can you explain it?
It describes the compressibility of a flow. It's intuitive that a mechanics problem with different densities in different areas is going to greatly complicated a solution. In computational/mathematical terms, the Mach number will determine if your governing equations are elliptic, parabolic, or hyperbolic, which has big consequences in how you attempt a solution.

[OP !jyyGvyuDkk No.4354251]

>>4354126
>Do you know a good book/reference for the limit from the full Boltzmann-equation descrption of gases down to conventional fluid dynamics?
I don't, admittedly I'm not well versed in statistical mechanics, but any book on the subject should have that.

>Are you familiar with plasma instabilities?
Yes, but more familiar with pure fluid instabilities. I've studied plasma instabilities in fusion devices though, yes.

>Are all people at your working place as intolerant to several other fields of study?
"as intolerant"? as what? I'm at a university filled with people that just love to learn, and there is no intolerance of other fields at all. Specifically "aerospace engineering" is one of the most multi-disciplinary STEM fields there are; you have coursework in a wide range of areas from materials to structures to aerodynamics to orbital mechanics to controls to systems engineering.

[OP !jyyGvyuDkk No.4354264]

>>4354135
>Did you happen to see that thread a few months ago about the guy who wanted to try to send a small rocket into orbit? Do you think it's possible for a one or two man team to put something into orbit on a hobbyist budget?
Didn't see it. I haven't worked with rockets/orbital mechanics in a while, so I'm not sure, but I'd first look into the mass of something like that. My first instinct is that a hobbyist budget couldn't put together something massive enough to get to orbit (talking the structure versus fuel mass), but I could easily be wrong.

[OP !jyyGvyuDkk No.4354275]

>>4354153
Ahh, launched from a weather balloon, maybe. That's a good undergrad problem for budding rocket scientists. Find the delta-V necessary to achieve LEO from 90,000 ft.

[OP !jyyGvyuDkk No.4354312]

>>4354151
-_-

[OP !jyyGvyuDkk No.4354619]

I'm gonna step out for some food/booze. Consider this a bump and i'll come back and answer questions.

[Anonymous No.4354629]

Is Robert Zubrin crazy? Or is Mars Direct plausible.

[Anonymous No.4354650]

Is Pointwise a program?

Do you like the field/problems of instabilities?
Also, can you motivate why turbulence occures from the navier stokes equation? Certainly the rot term is big for rotating vector fields, but I don't see why the equations imply the evolution of spiraly inwards thingys.

And I remember you complaining about pure mathematics, that's why I asked.

[Anonymous No.4354653]

>>4354275
do you really use feet? Or do you use the metric system in engineering?

[Anonymous No.4354659]

Who was better, von Braun or Koroliov?

[Anonymous No.4354660]

how can i use CFD to get a gf

[Anonymous No.4354669]

>>4354660

[Anonymous No.4354675]

>>4354669
>cocoa butter

what if i don't want a black gf

[OP !jyyGvyuDkk No.4355523]

>>4354660
>how can i use CFD to get a gf
It worked for me. You explain to them how awesome it is. Girls love it.

[OP !jyyGvyuDkk No.4355524]

>>4354659
>Who was better, von Braun or Koroliov?
von braun

[OP !jyyGvyuDkk No.4355529]

>>4354653
>do you really use feet? Or do you use the metric system in engineering?
We use any units. If the unit of measurement in your field trips you up, are you terrible, no matter what. It's a stupid thing to even discuss.

[Anonymous No.4355536]

>>4355523
no way.

the only part of engineering that girls like is when i talk about fast cars/motorcycles because that's the only thing that they think is cool about engineering.

[OP !jyyGvyuDkk No.4355546]

>>4354650
>Is Pointwise a program?
Yes.

>Do you like the field/problems of instabilities?
Sure, it's quite interesting.

>Also, can you motivate why turbulence occures from the navier stokes equation? Certainly the rot term is big for rotating vector fields, but I don't see why the equations imply the evolution of spiraly inwards thingys.

Rotation? not so much. The nonlinear term in Navier Stokes is the advective derivative. Lots of named instabilities come about from it.

[OP !jyyGvyuDkk No.4355551]

>>4355536
You're probably boring and unattractive. Real non-engr girls think engineering is awesome because (a) I have solid income, (b) I can give them very smart babies.

[Anonymous No.4355557]

Are there any jobs available for CS / Computational Math majors in aeronautics? I would like to one day work for NASA if I manage to get myself into grad school and a PhD program for CS

Also, thankyou for doing what you are doing, aeronautics research and work I mean

[Anonymous No.4355564]

when the oil price increase which will have high impact either long haul aircraft or short haul. I mean which kind of aircraft keeps the airliner profitable. Though the increase in oil price will have an impact on both kind of aircraft

[Anonymous No.4355687]

Oh, this thread is cool. I'm in junior year of undergrad now, doing a double major in aerospace and mechanical engineering. I know I want to go to grad school and specialize in fluid mechanics, and I'd love to get a phd. I'm kind of overwhelmed at how rich fluid mechanics is as a field though. There's turbulent flow, hypersonic flow, aerodynamics, CFD, and I know that my current prof does research in bio-inspired propulsion. Every time I read a bit more about fluids, it seems like I discover some cool new research area.

I enjoy programming, so I've been thinking I might want to get into CFD. There's a few other things that interest me too, like turbulent flow, and flow inside turbomachinery. So, what advice would you give to someone who's leaning towards CFD, but isn't completely sure yet?

[Anonymous No.4355819]

>>4354629
>yfw I interned at zubrin's company in Colorado for a couple summers as a teen

No joke. Cool guy, pretty harsh though. Walks funny. Has an awesome dog.

[Anonymous No.4355844]

what's your preferred method of domain decomposition?

[OP !jyyGvyuDkk No.4356593]

>>4355844
Schwarz w/ multigrid

[OP !jyyGvyuDkk No.4356601]

>>4355687
Do CFD. Experimental is a dead end.

You can start off doing OpenFOAM tutorials, and maybe try your hands and simulating things from Van Dyke's album of fluid motion. Anderson's CFD book has some simple algorithms you can code up, see if it tickles your fancy.

[Anonymous No.4356612]

How many rockets have you fired?

[Anonymous No.4356615]

did you pass your qualifiers?

[Anonymous No.4356618]

>>4356615
oops, nevermind.

[Anonymous No.4356620]

How do I get into Aerospace Engineering if I already failed High School

[Anonymous No.4356634]

What is the hardest AEng course?

[OP !jyyGvyuDkk No.4356637]

>>4356634
Typically aerodynamics.

[Anonymous No.4356644]

>>4356612
the only important question. tell us OP

[Anonymous No.4356651]

Why be an alcoholic when there are so many substances that have less side effects perturbing to your health and that induce a much greater sense of euphoria? Most wouldn't even shit up your productivity as much, some would even enhance it.

[Anonymous No.4356647]

with the state of the economy and the near future in mind, how valuable / in demand will my physics degree be?
Compared to an engineering degree.

[OP !jyyGvyuDkk No.4356690]

>>4356647
I think you probably know the answer to that.

[OP !jyyGvyuDkk No.4356691]

>>4356651
Availability, legality, and social acceptance.

[Anonymous No.4356747]

>>4356691
Describe your dream space program, and the five historical dudes you'd want to resurrect in their prime to have work with von braun.

[Anonymous No.4356752]

How much of a drunk are you?

Captcha related? : formed soonson
your space program's looking promising.

[Anonymous No.4356766]

Do you work with mechanical engineers? How do the duties of mechanical and aerospace majors compare?

[OP !jyyGvyuDkk No.4356777]

>>4356766
>Do you work with mechanical engineers? How do the duties of mechanical and aerospace majors compare?

They're generally about as similar as any two engineering majors can be. Lots of overlap, aerospace just gets cool applications. "Mechanical engineering" sounds like you change oil in cars.

[OP !jyyGvyuDkk No.4356779]

>>4356752
>How much of a drunk are you?
Kinda bad. I go through phases of being pretty drunk "only" 1-2 nights a week, to maybe 5 days a week.

[Anonymous No.4356781]

>>4353060
so you're in charleston

[OP !jyyGvyuDkk No.4356788]

>>4356747
>Describe your dream space program,
It's political, first and foremost. Let's start with 5% of the national budget. The average American already thinks NASA's budget comprises 20% of the federal budget.

>and the five historical dudes you'd want to resurrect in their prime to have work with von braun.
Ha, interesting question. I'd have to think about it. Not a space guy, but let's start with Kelly Johnson.

[Anonymous No.4356803]

Would it be a good idea to double major in mechanical and aerospace? My university offers this, and I'm interested.

[OP !jyyGvyuDkk No.4356810]

>>4356803
Depends how many extra courses you have to take, what you want to do afterwards, etc.

[Anonymous No.4356813]

I'm looking to take aerospace engineering at Oxbridge. Any idea how difficult getting a job in this field will be after graduation?

[OP !jyyGvyuDkk No.4356826]

>>4356813
I have no idea what the job situation is like outside the US. Not difficult at all to find work here, if you do reasonably well.

[Anonymous No.4356927]

I'm a third year mechanical engineering student.

I want to into rocket science.

I fucking love space.

I'm in England.

What do I do?

[Anonymous No.4356974]

>>4356927
Research at Cranfield

Join ESA with post doc

[Anonymous No.4357015]

>>4353060

staff or student?

[Anonymous No.4357160]

What would it take to be the CEO of an aerospace company?

[OP !jyyGvyuDkk No.4357291]

>>4357160
I've met one. Intelligence, charisma, confidence, character. A personality that you want to put in charge.

Imagine the stereotypical 4chan user. The opposite of that.

[Anonymous No.4357306]

>>4357291
OP is right - it's more at that point about interpersonal skills than your actual knowledge.

Sure, you DO need to know a lot, but you've got the underlings to do the actual work - you just manage this show.