# Tag Info

## Hot answers tagged pipelines

2

The terms you are looking for are Major and Minor pressure losses. Which are a misnomer for systems on the scale your are talking about, since "Minor" losses are usually the greater. The pressure drop across any feature of the system (sudden expansion, sudden contraction, a split, a component like a valve) is: $\Delta P = 0.5 k\rho Q^2/A^2$ $\rho$...

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In flow problems, it's generally a good idea to work backwards in realtion to the flow: Find where each branch is ending and the pressure at this point (height, atmospheric pressure, $p_{out 1}, p_{out 2}$ ). Then, find the relation between pressure loss and flowrate for each branch ($\Delta p_1(Q_1), \Delta p_2(Q_2)$). You know the the pressure at the ...

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If I understand your question correctly your qualm is about $\tau$ being negative. I will use the same image as karman because it is a very good one: you will notice that shear stress is defined as: $$\tau = \mu\frac{d u}{dy}$$ Now notice in your image: that for increasing y, the velocity increases up to the middle of the pipe. (That is because the fluid ...

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If I get your point correctly, It is only a sign convention. say in a pipe with the positive flow gradient we consider a plane C parallel to the pipe axis. The shear stress above the Yc plane is considered positive and the shear stress below that same plane is considered negative. both of these stresses are due to $\tau \$ which is positive. and the sum of ...

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Obviously putting it in series is better than the other two options. Putting in series, means that If you put two (perfectly calibrated) flow meters in series, then you will be able to make inferences on the actual value based on the calibration uncertainty, the reading uncertainty, and the sampling statistics. Problems with the other setups I'll start with ...

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The key principle is that, when expressed in terms of the non-dimensional head coefficient $K_H := gH/\left(D\omega\right)^2$ and the non-dimensional flow coefficient $K_Q := Q/\left(D^3\omega\right)$, there is a single head-flow characteristic for the whole family of geometrically similar pumps. That is to say, when expressed in terms of those quantities, ...

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The symbol $H_{\mathsf{C}}$ here doesn't represent a head loss, it represents an "absolute" head at point $\mathsf{C}$. Assuming that the fluid velocity in the region vertically above $\mathsf{C}$ is negligible, so that the pressure variation in that region is hydrostatic, that absolute head is equal to the vertical co-ordinate of the free surface ...

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