Salomon Turgman
  • Member for 6 years, 10 months
  • Last seen more than a month ago
  • Kettering University, Campus Drive, Flint, MI, United States
What is the physical interpretation of the second term in the viscous stress tensor in the Navier-Stokes equations?
Accepted answer
12 votes

You should not separate those two terms in search for physical interpretation. The term $\nabla\vec{u}+\left(\nabla\vec{u}\right)^T$ is the strain rate tensor $\dot{\gamma}$. The momentum flux (or ...

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How are thermodynamics properties of gases and liquids calculated numerically?
Accepted answer
4 votes

The answer is using a thermodynamic equation of state (EOS). An EOS is one that relates the free energy of a substance to its physical properties (temperature and density for example). Once such an ...

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How can I calculate the evaporation rate for a hazmat spill?
3 votes

The evaporation formula you have is a modification of the EPA method for calculating the evaporation rate. See here: Technical Guidance for Hazards Analysis look at Appendix G. The modified form I ...

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Force Balance Question
3 votes

Your Average MechEng's answer is fantastic and it is often how I explained the area of a thin circular shell to my students. But the mathematical derivation of such formula might be of interest to ...

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One large fireplace flue versus two smaller ones
3 votes

I am attacking this problem from the point of view of the flow of the gas itself through the chimney. So what I am looking at is whether using two vents vs one increases speeds of the flow to the ...

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Is there a relation between porosity and PPI density in porous media?
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2 votes

The answer is system specific. That is, unless you know something else about the structure of your porous material, there is no clear relation between pore density and pore size. A simplified 2D ...

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Can the continuity equation and Bernoulli contradict each other?
1 votes

I think @sam is correct. To provide some intuition here, imagine that we have a pipe that does what is described in the problem but that had constant diameter throughout. In this case, the pressure at ...

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Silicon and silicones
1 votes

The key characteristic of silicone polymers that make it so versatile is that they are not a single compound. Just like polyurethanes are extremely versatile organic polymers, polysiloxanes are ...

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How does one calculate degrees of freedom in a reactor with parallel reactions?
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1 votes

The answer to your questions is that you calculate the DOF for a reactor with parallel reactions the same way you would any other process. Your problem is unrelated to the fact that you have parallel ...

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External diffusion: calculation of surface concentration
1 votes

The way you have solved your problem you have treated the concentration at the surface of the sphere as known ($y_{B,\text{surf}}$). Notice that in your final answer, if you plug in $r=r_\text{sphere}$...

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Fluid dynamics of non interacting tanks in series
0 votes

$Q_p$ seems to be the inlet volume flow. Assuming that you know the initial steady state values, you could calculate $A_D$.

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Working Out Shaft Torque in a Stirred Tank with a Cylindrical Cavern Formation (using a non Newtonian fluid)
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0 votes

For your curved surfaces, the lever arm for the calculation of torque is a constant $D/2$. That is not true in the case of the cavern's faces. In that case the lever arm is a variable ($r$). To ...

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Normalization and Non-Dimensionalization of a mass balance equation
0 votes

When you want to work with non-dimensional variables you should also look at the boundary and initial conditions of the problem. That way you can check whether non-dimensional groups appear in the ...

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