We were discussing the difference between Notches and Weirsdischarge over a triangular notch or weirexpression for discharge over a rectangular notch or weiradvantage of triangular notch or weir over rectangular notch or weir and also the discharge over a trapezoidal notch, in the subject of fluid mechanics, in our recent posts.

Now we will go ahead to find out the discharge over a stepped notch, in the subject of fluid mechanics, with the help of this post.

As we can see here, in following figure, that a stepped notch will be the combination of rectangular notches. Therefore, discharge through a stepped notch will be considered as the summation of the discharge through different rectangular notches.

Let us consider that we have a stepped notch as displayed here in following figure.

H1, H2 and H3 = Height of water above the crest of notch 1, notch 2 and notch 3 respectively
L1, L2 and L3 = Length of the notch 1, notch 2 and notch 3 respectively
Cd = Coefficient of discharge of all notches

Discharge through the stepped notch = Q1 + Q2 + Q3

We have already discussed the discharge through the rectangular notch and therefore we will have following expression for the discharge through a stepped notch as displayed here.

Now we will go ahead to start a new topic in the subject of fluid mechanics i.e.

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### Reference:

Fluid mechanics, By R. K. Bansal