Recent content by MrMatt2532

Take an element on the pipe wall. The forces felt on the wall due to the fluid are going to be the skin friction in the tangential direction and the pressure (aka the static/thermodynamic pressure) in the normal direction. Note that technically, in general, something called normal shear is...

I think your diagram looks ok, except for a somewhat minor point: Instead of ΔS, it should be dS. In this form it will tell you the instantaneous change in entropy in your system. Alternatively, you need integrals on the other side of the equation. In this form it will tell you your change in...

The potential energy between two objects is -G*m*M/r. If you put work into the system you can increase the separation vector r, or you can take work out of the system and decrease the separation vector r. No contradictions here. You seem to be thinking that you are doing work on one object and...

Again, I think you mostly have it but you need to be careful. When you are analyzing the universe (or an isolated system), there is no external heat transfer, and you can only say that change in entropy of the universe (or the isolated system) is due to internal entropy generation. Basically...

Well part of your issue is that you seem to be thinking about what is happening outside your control volume. You shouldn't even need to consider those things if all you care about is change in entropy inside your control volume. The basic idea is, inside your control volume, you can increase or...

Yes, so the deltaQ in the deltaQ/T term refers to heat transfer at the boundary (i.e. between your control volume and some adjacent control volume), which is the reversible part. Note that in practice it is hard to have heat transfer at the boundary without internal heat heat transfer as well...

Looks like you on thinking about it correctly. Sgen can be due to internal heat transfer or internal friction (among other things, but these are the most basic I would say). Whenever you have entropy generation you have an irreversible process. So yes, it is correct to say...

Assuming ρ is in [kg/m3] and v is in [m/s] and A is in [m2], then yes P is in watts.

Is this core/restriction porous? Also, what is your goal? To find the pressure drop caused by the core/restriction?

The simple answer for spanwise variation is that turbulent flow in inherently unsteady and 3 dimensional even if you would like to view it as a 2-dimensional problem. As to the streaky nature, it is unclear if you are referring to fully developed turbulent flow or laminar flow transitioning...

I didn't read the document, but you can construct a basic model just by knowing two forces: the bouyancy force and the weight force. (mass_basket+mass_balloon+mass_air_in_balloon)*g = Volume_balloon*g*density_surrounding_air This equation would be for if the balloon were not accelerating...

Also, regarding the bat velocity. Instead of solving for v_ball, you could have solved for v_bat. You should find that v_bat_final equals v_bat_initial in the same direction. Think of a train hitting a bug, the train is not going to slow down whatsoever.

I glanced at the work briefly. I think you aren't cancelling out the mass in the numerator and denominator properly. The units of you velocity needs to be a velocity, not a velocity per unit mass. For example, in the last equation you have written, it should be -299*m*v/(101*m)=-2.96*v

Yes this is correct. EDIT: what do you mean with the v/m part? The velocity should essentially be 3 times the initial velocity in the opposite direction.

Well can you let me know basically what you have tried so far and where you are currently stuck regarding what I have already said? I am guessing you have used conservation of momentum and conservation of kinetic energy. From this you have two equations and two unknowns: velocity of the ball...