100 reputation
8
bio website
location Left of Warsaw, Right of London.
age
visits member for 1 year, 10 months
seen Aug 4 at 12:12

Nov
4
comment Difference resultant aerodynamics force on an airfoil and a flat plate
Meaning that the $R$ force can only be decomposed in the $L$ and $D$ force if the $A$ force is neglected?
Sep
3
comment What is the drag coefficient of an open wedge?
this may not be easy, but it will have been done - unfortunately I don't have a reference to hand That's the problem exactly. I'm sure there must be something on it but no I failed to find any references as well. I only found something in the Fluid Dynamic Drag book of Hoerner on the open wedge shown in the first image, but the flow coming from the right.
Apr
23
comment In terms of the Doppler effect, what happens when the source is moving faster than the wave?
From the supersonic image it seems that an observer standing just below the line of motion would first hear the most recent sound waves and after that the less recent waves. Does that mean he would hear the sound in reverse?
Apr
12
comment Effective angle of attack of a wing
In my question I assume a yaw angle of 0. My point is that when you have a wing with dihedral and you pitch it up, the angle of attack on the wing is different than it would be without dihedral.
Mar
27
comment Metronome synchronisation applied to swings
@annav Thanks for the links, but these motions are not really coupled in the same way as the metronomes are. Is that a big difference?
Nov
6
comment Force in tetrahedron edges
I've added a calculation for the force in the three lower beams.
Oct
21
comment Necessary air pressure in flexible vessel to lift a certain mass
This answer is only partially right. @FrankH makes a valid point by involving the surface tension in this. That, the shear stress in the wall of the bag and the boiler equations are somehow involved, I think...
Oct
12
comment Necessary air pressure in flexible vessel to lift a certain mass
OK, thanks for the answer. I'm still curious about the part with the bag size. Would you know an analytic relation between bag volume and pressure? Say I have a bag with 10L volume, how much air should I put in it to achieve the necessary pressure?
Oct
12
comment Necessary air pressure in flexible vessel to lift a certain mass
This is indeed not a homework problem, but for a DIY project. Do you mean that I should add the homework tag nonetheless? I was not aware of the availability of TeX, I will update the formula asap.