FrenchKheldar
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 Aug 28 comment How laminar or turbulent is air? Turbulent state is defined for a flow, not a fluid. So you have to define what the air flow you want to consider? Flow around you as you walk? Flow around a candle or an incense stick? Cannot answer the question satisfactorily without more details. Dec 11 comment How can these fluid dynamical smoke-ring phenomena be explained? I will look into the second point more and maybe do some diagrams if I find the time... Dec 10 comment Is the liquid/solid line infinite? That's interesting although raises quite a few new questions. Your phase diagram shows that it becomes very difficult to have liquid phase above 10^9 Pa. Is that behavior (vertical solid-liquid line becoming nearly horizontal) specific to water? Can this 10^9 limit be estimated a priori from atomic quantities? Dec 9 comment Is there a small enough planet or asteroid you can orbit by jumping? Other problem: finding a perfectly spherical asteroid. Irregular shapes will make this a lot more difficult ! Dec 9 comment Is there a small enough planet or asteroid you can orbit by jumping? You don't necessarily come back to your original location after your jump. Any other ballistic trajectory is possible if your speed is below the escape velocity. Dec 9 comment Flames with no gravity? I might have more on this in a few days, but couldn't resist to answer something already. Let me know if specific points are not clear... Dec 4 comment fitting van der waals law on real data You have to go to the fluid properties section. Nov 24 comment Mass diffusion: is $D_{AB} \neq D_{BA}$ at high pressures? If so, why? Nicely put ! That's what I think too, let's see what other answers we get. Nov 12 comment What velocity must an aircraft achieve for its shock wave to transform to plasma? Here it is, sort of. I can't link to the chart I was thinking about from Anderson, High Temperature Gas Dynamics, but this should do Check Fig. 1.1, they put the ionization limit at around 10 km/s which seems higher than what the Space Shuttle reaches, and yet I'm pretty sure there is a plasma cloud around the SS. I will research this further... Nov 12 comment What velocity must an aircraft achieve for its shock wave to transform to plasma? Given that the Space Shuttle create a plasma during reentry, I doubt your calculation of 4E7 mph was correct... I'm looking for a chart that shows Cp and $\gamma$ of air vs Mach number and altitude but I can't find it... Nov 10 comment How do black holes accrete mass? I thought your question implied that it would take an infinite amount of time for the man to fall in the black hole. Which is not true. Also, I always thought the size of the black hole was smaller or equal to the Schwarzschild radius, which is the event horizon. Nov 9 comment Gas kinetic representation of trans-critical conditions Nov 9 comment Gas kinetic representation of trans-critical conditions And then what I want to understand better is what happens at a molecular level for the macroscopic surface tension to disappear? Is this because the rate/energy of collisions becomes large enough? Nov 9 comment Gas kinetic representation of trans-critical conditions So maybe I was not clear but the two drawings (left and right) are meant to illustrate the two paths (upper and lower) on the phase diagram. I'm considering a constant pressure system where I have a spatial temperature gradient. I'm considering a snapshot in time. Nov 9 comment Gas kinetic representation of trans-critical conditions So no opinion whatsoever on this? Bounty coming up I guess... Nov 7 comment Is the EmDrive, or “Relativity Drive” possible? Here is the latest paper translated in English [emdrive.com/yang-juan-paper-2012.pdf] Nov 7 comment Is the EmDrive, or “Relativity Drive” possible? I hadn't seen this question before and I [skeptics.stackexchange.com/questions/13543/… posted] something related to it on skeptics... Apparently there are some new claims from the Chinese researchers that this works. Has anybody read these papers? Do we know anything more about this? Mar 5 comment Questions about compressing a liquid in a piston When you say "If you push the piston further, the water will mostly just push back." that does indicate that of course my equilibrium pressure (i'm pushing very slowly) is increasing.I think my mistake was that in the case you do get a pure liquid in a given volume, the p-T conditions can be outside the boiling curve and thus there will be no evaporation right? Mar 5 comment Questions about compressing a liquid in a piston Well in my thought experiment, I cannot determine the temperature, but you are right, I probably should have called the fluid a compressed liquid (top-left quadrant of the p-T diagram) and not a supercritical fluid. Let me digest the rest... Feb 6 comment What is the velocity area method for estimating the flow of water? Your last edit about the incompressible fluid makes sense and I guess I misunderstood that you were still under that constant acceleration assumption. Sorry !