calculation of flow through a slot

[geoffd5058]

Hi

I want to calculate the liquid flow through the opening formed by failure of a flange gasket between two bolts in a four bolt flange.
I can't find any specific method for this calculation - is there one ?

I've downloaded a couple of fluid flow texts, but flow through this type of slot doesn't seem to be covered.

I can see that either using the equivalent area of a circular orifice, or the equivalent diameter of the circumference of the square(ish) slot might work, but neither seem really appropriate.

Surely this is a commonly analysed failure ?

Help.

Geoff

[barryn56]

Try the Francis Weir formula. This can also be modelled in Mathworks, for example.

[geoffd5058]

I thought about that. I don't think a weir formula is appropriate either because 'the fourth side' is a free surface. What I want is essentially a calculation for a non-circular orifice.