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location Atlanta, GA
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visits member for 2 years, 10 months
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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.


Oct
17
reviewed Approve suggested edit on Why don't free electrons fall from metals if shaken?
Oct
15
comment Tensorial version of Hooke's law
Unfortunately, there is no easy answer. You can start with this page although you probably have read it already. If you are trying to relate elastic properties to spring constants, you will have a tough time. I just wrote my thesis on these very issues. You will find this paper helpful to show you how there is more than 1 way to get spring constants just from $E, G, \nu$, let alone the full $C$. And it is geometry dependent.
Oct
14
comment What is the physical meaning of complex eigenvalues?
This is 100% a guess since I don't work in acoustics but if the frequency is complex, then the imaginary part is likely a phase shift.
Oct
9
comment Gas viscosity at high pressure, high temperature
I'll take a look (maybe not tonight though) -- I defended my MS thesis today and I don't really want to work at the moment! But that may pass. I'll see if I can think of anything.
Oct
9
comment Does measuring the air temperature near a 21 lane asphalt highway impact measurements?
The real question -- absent wind, does the temperature of the highway affect something a few hundred feet away laterally and 6 feet high? Even accounting for wind, perhaps the predominant wind blows the heat away from the sensor?
Oct
8
comment In a column of fluid does density vary?
Related question that might shed light here (but isn't an exact duplicate) physics.stackexchange.com/questions/139346/…
Oct
8
comment Gas viscosity at high pressure, high temperature
I don't have time to summarize this article for a full answer at the moment (so if you figure it out before I do write an answer, then answer it yourself!) but this should give you what you need: boulder.nist.gov/div838/theory/refprop/NAO.PDF Including references and details on computing it from first principles using collision integrals and the like.
Oct
8
comment Gas viscosity at high pressure, high temperature
As it stands, I'm not sure what you're asking exactly. Are you looking for more advanced models? Models that are linear? Models that work at high temperature (600K isn't actually very high temperature)? Do you need only nitrogen? Or any species? And when you say based on the underlying physics, which physics exactly? Sutherland's law is just a curve fit and not really based on physics.
Oct
8
comment What is a Physically Accurate Explanation for the Kutta Condition?
@BrysonS. Perhaps you should start another question thread with your specific questions about the vortex shedding process? Also it's not "spanwise" in 2D since there is no "span" to speak-of. I assume you just meant vortex shedding from the trailing edge, as opposed to the 3D shedding of tip vortices. But anyway, thanks for accepting and if you manage to post up a question about the vortex shedding process I'll see if I can answer it.
Oct
8
awarded  Enlightened
Oct
7
comment Hot wire anemometry and gas species
I guess a better question is what have you searched for -- there's a ton of literature out there for determining calibrations in multicomponent flows. I'm not an experimentalist so I can't provide a more recent example without searching longer, but here's a paper from 1970 for determining both concentration and velocity using hot wires. I bet if you traced citations from that paper forward or backward in time, you'll find the information you need.
Oct
7
comment Hot wire anemometry and gas species
What have you tried? Normally anemometers must be calibrated in low-turbulence flows of known velocity to get the calibration coefficients. Is there something that makes you think that won't work for anything other than air?
Oct
7
comment Do weather conditions change after sunset?
@Jim Atmospheric sciences (fluid dynamics and physics) are on topic here and this question shouldn't be closed. It may also be on topic elsewhere, but that's not a reason to close it here.
Oct
7
answered Do weather conditions change after sunset?
Oct
6
comment Example of materials with 21 independant coefficients in linear elasticity?
Yes, that's exactly why I need to have them generalized like that. I personally have not simulated something with all 21 coefficients, but I have simulated ones with different symmetries so I have entered all 21 at some point. If that makes sense...
Oct
6
comment Example of materials with 21 independant coefficients in linear elasticity?
I don't know for sure so I can't answer. However, if triclinic crystals are an example, then there is at least one explosive that would be. However, I know from implementing a structural solver (for explosives) that even if they are not all independent, one must often write code as if they were because the symmetric terms are different for each material and orientation.
Oct
6
comment vortex doublet in 2D
@CuriousOne But for a great number of problems, you don't need to worry about the boundary layer flow. A jetliner at cruise for example. So yes -- potential flow solvers do not have all the physics in them, but for a great deal of engineering problems one does not need all the physics in there. If you can predict lift during design phases, and do it in ~45 minutes on an engineers workstation, you can quickly rule out designs that aren't worth further investigation in either the wind tunnel or a full CFD solver. Which doesn't need to be solved with finite elements (and usually isn't).
Oct
6
comment vortex doublet in 2D
@CuriousOne No, not always. Boeing uses potential flow solvers to do parametric studies all the time. Many aeroelastic applications use unsteady potential solvers which may or may not be coupled to a structural solver. Perhaps that is what you are referring to with finite elements, but they are solving two different domains. Potential flow is still a very important analysis tool. Heck, we still use panel methods frequently.
Oct
6
comment Turning a finite difference equation into code (2d Schrodinger equation)
@SideshowBob You can do a simple 2nd order Runge-Kutta time integration with 2nd order differences in space. It is much simpler, but may take a long time due to explicit scheme time step restrictions.
Oct
6
comment vortex doublet in 2D
@CuriousOne Totally disagree. Modern computers are awesome, but you still can't get several flow through times over entire aircraft for dozens or hundreds of parametric design studies without potential solvers.