GrahamC001
Civil/Environmental
Hi,
We are designing an overspill gate weir and need to ensure ventilation of the the nappe to avoid vibration. Designing the vent pipes is proving to be a bit of a challenge. Can you suggest any references we can refer to?
In general sizing is OK, but what is not clear is what reduction in pressure is tollerable. Most references we have identify refer to Bos "Flow Measurement Structures", which seems to suggest a pressure reduction under the nappe equivalent to 0.04m of water. However this Bos is focused on gauging weirs and so its important to minimise subatmospheric pressure below the nappe to maintain the rating of the weir. That's not an issue for us, we just need to ensure that we don't get vibration. Any guidance on how to indentify an allowable pressure under the nappe for this (less onerous) criterion would be much apprecited!
Many thanks,
Graham
We are designing an overspill gate weir and need to ensure ventilation of the the nappe to avoid vibration. Designing the vent pipes is proving to be a bit of a challenge. Can you suggest any references we can refer to?
In general sizing is OK, but what is not clear is what reduction in pressure is tollerable. Most references we have identify refer to Bos "Flow Measurement Structures", which seems to suggest a pressure reduction under the nappe equivalent to 0.04m of water. However this Bos is focused on gauging weirs and so its important to minimise subatmospheric pressure below the nappe to maintain the rating of the weir. That's not an issue for us, we just need to ensure that we don't get vibration. Any guidance on how to indentify an allowable pressure under the nappe for this (less onerous) criterion would be much apprecited!
Many thanks,
Graham
