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  1. Chestermiller

    Pressure loss pipe system: Conversion from known fluid1 to fluid2

    What are the densities and viscosities of the two fluids? Are you comparing them on the basis of the same mass flow rate or the same volume flow rate?
  2. Chestermiller

    Irreversible quasi-static processes?

    None of this makes any sense to me, and most of it is wrong. Also, please do not use differentials for irreversible processes.
  3. Chestermiller

    Pressure loss pipe system: Conversion from known fluid1 to fluid2

    If the flow truly is laminar, and there are no changes in elevation (so the density doesn't matter, assuming constant volume flow rate), the pressure drop is going to be proportional to the viscosity. But, aside from polymer melts and solutions, I highly doubt that the flow will be laminar. If...
  4. Chestermiller

    Pressure loss pipe system: Conversion from known fluid1 to fluid2

    This is not quite correct, because the friction factor is going to depend on the Reynolds number, which is inversely proportional to the fluid viscosity.
  5. Chestermiller

    Irreversible quasi-static processes?

    If the expansion is reversible (quasi-static), you can use the ideal gas law to get the pressure of the gas at the piston face where the work is being done (and it is equal to the external pressure of the piston face on the gas). If the expansion is irreversible, an ideal gas does not satisfy...
  6. Chestermiller

    I Boundary Conditions For Modelling of a Fluid Using Euler's Equations

    No problem. Just make sure that the values match at the upper right corner. No problem. The boundary condition is just that the tangential component of stream function is constant. You don't need to set the value there. The differential equation becomes $$\frac{\partial^2 \psi}{\partial...
  7. Chestermiller

    I Boundary Conditions For Modelling of a Fluid Using Euler's Equations

    Yes. Sure. It is just that the potential function is discontinuous at the boundaries. Try specifying a better example to study.
  8. Chestermiller

    I Boundary Conditions For Modelling of a Fluid Using Euler's Equations

    You can set those boundaries in motion tangentially in any way you want, and it still is not going to cause any fluid flow within the region. Discontinuities in tangential velocity are perfectly comparable with inviscid flow.
  9. Chestermiller

    I Boundary Conditions For Modelling of a Fluid Using Euler's Equations

    I'm not sure I understand what you are saying. The flow is into the region across the left boundary and out of the region across the right boundary? There is no flow across the upper and lower boundaries? Across the left and right boundaries the velocity in the x-direction is a quadratic...
  10. Chestermiller

    I Boundary Conditions For Modelling of a Fluid Using Euler's Equations

    What is the specific geometry and flow you’re looking at?
  11. Chestermiller

    I Boundary Conditions For Modelling of a Fluid Using Euler's Equations

    Why don’t you solve this using the stream function, which satisfies Laplace’s equation?
  12. Chestermiller

    A Crank-Nicholson solution to the cylindrical heat equation

    I have some ideas on how you can proceed to get your CN program to work properly. Phase 1: To test out your spatial finite difference scheme, solve the problem using forward Euler (rather than CN ) with a small enough step size that the solution remains stable. Phase 2: Use the CN equation...
  13. Chestermiller

    Equilibrium value for carbonation level in beer

    It looks to me like your approach was correct. I haven't checked the arithmetic, however.
  14. Chestermiller

    Thermodynamics Problem: Reversible and Irreversible Processes

    I am not going to discuss Problem 1 because I am opposed to using differentials for irreversible processes. For problem 2, I would add that, if the entropy of state B is higher than state A, then, if you could use an adiabatic irreversible path to go from state B to state A, the entropy would...
  15. Chestermiller

    Can I apply Bernoulli's equation to this situation?

    After further consideration of this situation, I totally agree.
  16. Chestermiller

    Can I apply Bernoulli's equation to this situation?

    If I remember correctly, the OP showed some dimensions on his original post (which was later edited).
  17. Chestermiller

    I Water in a tank being driven up and down

    So the liquid is not displacing up and down like a rigid body?
  18. Chestermiller

    B Vapour pressure of water vapour in air

    At equilibrium, the partial pressure of water vapor in the air is equal to the equilibrium vapor pressure. This is because, in an ideal gas mixture, each gas behaves as if the other gas is not present.
  19. Chestermiller

    I Water in a tank being driven up and down

    small ##b/\Omega_1##. Make a graph and see what it looks like.
  20. Chestermiller

    I Water in a tank being driven up and down

    I think you are going to want the frequency to be changing a small amount over each cycle.
  21. Chestermiller

    Can I apply Bernoulli's equation to this situation?

    To get your feet wet, start out by considering the problem where there is no flow from the pump.
  22. Chestermiller

    I Water in a tank being driven up and down

    I don't understand what a model of the frequency sweep means.
  23. Chestermiller

    Can I apply Bernoulli's equation to this situation?

    I think that if you specify the flow at the pump, you can determine the pressure at the pump and the flows in the two arms using Bernoulli.
  24. Chestermiller

    I Water in a tank being driven up and down

    I think that you would then have to differentiate that twice with respect to time to get the instantaneous acceleration.
  25. Chestermiller

    Can I apply Bernoulli's equation to this situation?

    All the water would flow from the upper reservoir to the lower reservoir on the right. There would be no flow from 2 to 1 unless a huge flow were forced by the pump. It would have to provide a pressure of at least 10 psi.
  26. Chestermiller

    Volumetric flow from vessel through pipe to another vessel

    https://www.engineeringtoolbox.com/steel-pipe-schedule-40-friction-loss-diagram-d_1145.html 6 ft of water is about 2.6. psi. 2.6 psi over at 50' pipe is about 0.05 psi/ft. That would result in an initial flow rate of about 7 gpm for a steel pipe.
  27. Chestermiller

    I Water in a tank being driven up and down

    Don't you think that, if you are looking at things like that, you need to include liquid compressibility?
  28. Chestermiller

    I Water in a tank being driven up and down

    If the upward motion of the plate is $$h=A\cos{\omega t}$$, then the upward acceleration of all the fluid is $$-A\omega^2\cos{\omega t}$$. So, from the moving frame of reference, the equivalent upward gravity would be $$-g+A\omega^2\cos{\omega t}$$ and the equivalent downward gravity would be...
  29. Chestermiller

    A Crank-Nicholson solution to the cylindrical heat equation

    If you didn't make any mistakes, it would work. Try a calculation in which you use only 21 grid points and choose delta t such that it makes alpha close to 1.
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