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location Atlanta, GA
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visits member for 3 years
seen 19 mins ago

I'm working on my PhD in aerospace engineering, specializing in computational turbulent combustion. My focus is primarily on massively parallel algorithms and computational methods for solving fluid and structural mechanics problems. Primary work is done in Fortran (90, 95, and 2003) but recent work has me branching into python, C and C++.

I'm also interested in international affairs and law.

Also interested in applying computational techniques to sports, in particular cycling aerodynamics and performance optimization. Particular emphasis on track cycling and time trialing.


Dec
22
comment Can I use Runge-Kutta to solve these equations?
Even if you didn't want to do that substitution (and assuming everything else is correct) -- actually write out the discrete form of your equations as they are and it should be pretty easy to formulate the integration. Particularly if you write the left-hand side as a matrix multiplying a vector of {u,v}.
Dec
22
revised Why is the equation for friction so simple?
added 17 characters in body
Dec
22
comment How much heat from a fire actually warms your home?
That's why we can feel a fire from across the room as soon as it's lit but we no longer feel it once it turns off. The radiation is what is heating things (including the bricks in the chimney) far more than heating the air. Although in the intro to Tenekes and Lumley they do a dimensional analysis that shows it takes hours for laminar convection to move heat from a radiator throughout a room but only a few minutes if the air is turbulent.
Dec
21
comment How much heat from a fire actually warms your home?
Remember that almost all of the heat we "feel" when we sit in front of a fire is from radiation and it takes a long, long time to heat up the air in a house (relatively speaking).
Dec
20
comment Boundary conditions of stream function
Maybe just to give a little more help -- there are two types of boundary conditions. Dirichlet, which Kyle gave you a link to, and Neumann which could be more appropriate here depending on how you are going about the solution process.
Dec
20
comment Boundary conditions of stream function
Do you know what boundary conditions are? Really not trying to be glib, but @KyleKanos gave you literally everything you need in his comment. And your response contains everything you need.
Dec
14
revised Why is molar specific heat at constant volume of a monatomic ideal gas a constant?
added 532 characters in body
Dec
14
answered Why is molar specific heat at constant volume of a monatomic ideal gas a constant?
Dec
14
comment Physical examples where changing the order of limits yields wrong result
@alarge But the limits aren't changing -- OP isn't saying that instead of the integral from $a$ to $b$ it's now $a$ to $c \neq b$. That would be changing the limits. Instead, the question is about changing the order of the operators (or order of the limits) which is not the same as changing the limits.
Dec
14
comment Physical examples where changing the order of limits yields wrong result
You're not changing the limits. You're changing the order of operators which is only valid for linear operators (or commuting operators).
Dec
13
awarded  Yearling
Dec
11
awarded  Informed
Dec
11
comment Is the kinetic energy of an electron always $1.6 \cdot 10^{-19}~\text{J}$?
Even if you wanted to compute kinetic energy another way (not using voltage), the electron is moving at $0.5c$ so you can't just say $K = 1/2 m v^2$ and you need to use the relativistic expression for kinetic energy. Which also means you need to use the relativistic expression for momentum and not just $p = mv$.
Dec
10
answered Conservation Equations forming a Determinate Set
Dec
9
comment What is the error in a ruler?
I think you're confusing accuracy and precision. The ruler is only precise to within a half cm (to the eye of the user) while it's only as accurate as the spacing was made correctly. Using your picture, I can make that measurement 5 times and say that it's between, say, 10.3 and 10.5 each time. That's precision. But it really could be 15 because the hash marks are wrong, that's accuracy. Not that this is a full answer, but maybe that will help refine the question/answers.
Dec
7
awarded  Enlightened
Dec
7
awarded  Nice Answer
Dec
5
comment Why is a whistle sound emitted when air is pushed through a tight space?
@Floris Check out the page on how a whistle works. They say the air splitter is unsteady causing oscillations which generate pressure waves. The resonance chamber amplifies certain waves. I guess it's splitting technical hairs between the lay-definition of turbulence and the technical definition of turbulence, but oscillations in a fluid aren't technically turbulence unless they have specific characteristics. So I'll concede that unsteady flow features cause the noise, but I don't think it's turbulence. Just unsteady flow...
Dec
5
comment Why is a whistle sound emitted when air is pushed through a tight space?
I'm not sure if I buy the argument that it's due to turbulence... yes, the Reynolds number increases as it goes through the contraction, but it's also not an isotropic process. The vortices/eddies created are being "stretched" in the axial direction and squished down in the transverse direction. A careful reading of the Fipple wikipedia article says that the harmonics are created by turbulent effects, but the original tone I'm not so sure about... Something for me to think about here.
Dec
4
comment Like viscoelastic polymers, why there are not storage and loss moduli for cast iron?
You're confusing a lot of different topics here. Viscoelastic means stress does not cause permanent deformation (elastic) but the loading and unloading paths are different (visco). This is very different from plastic which means stress causes permanent deformation. There can be viscoplastic behavior in a material too. In other words, you're looking at two very different types of behavior.