Analisis of downhill pipeline
Analisis of downhill pipeline
(OP)
Dear community,
I'll appreciate your oppinions in how a downhill gravity pipeline is being analyzed.
The pipeline has changes of internal diameter and slope, altough it always is going downhill. The pipeline starts in a tank and discharges to a pond and has a flow requirement.
1) We analyzed each section that maintained diameter and slope, with a full pipe and no pressure scenario. We found that the flow in each section exceeds the required flow, so we concluded that the pipeline will work as an open channel.
2) We analized each section again supposing uniform flow. Started guessing how full the pipe was, then finding the losses and checking against the available height difference, and iterated until the values had no difference.
3) We found for each section the critical water height, and after comparing with the water height in each section found the flow was in supercritical regime. We don't know how to calculate the Froude Number for the situation.
I'm seriously in doubt in how to analize the discharge of the tank to the pipeline, the discharge of the pipeline to the pond, the changes of slope or diameter in the pipeline and if the uniform flow assumption is . My guess is that these are minor aspects of the pipelyne analisis.
Thanks for reaching here. I'll be expecting your comments.
Kind regards.
I'll appreciate your oppinions in how a downhill gravity pipeline is being analyzed.
The pipeline has changes of internal diameter and slope, altough it always is going downhill. The pipeline starts in a tank and discharges to a pond and has a flow requirement.
1) We analyzed each section that maintained diameter and slope, with a full pipe and no pressure scenario. We found that the flow in each section exceeds the required flow, so we concluded that the pipeline will work as an open channel.
2) We analized each section again supposing uniform flow. Started guessing how full the pipe was, then finding the losses and checking against the available height difference, and iterated until the values had no difference.
3) We found for each section the critical water height, and after comparing with the water height in each section found the flow was in supercritical regime. We don't know how to calculate the Froude Number for the situation.
I'm seriously in doubt in how to analize the discharge of the tank to the pipeline, the discharge of the pipeline to the pond, the changes of slope or diameter in the pipeline and if the uniform flow assumption is . My guess is that these are minor aspects of the pipelyne analisis.
Thanks for reaching here. I'll be expecting your comments.
Kind regards.





RE: Analisis of downhill pipeline
David Simpson, PE
MuleShoe Engineering
"Belief" is the acceptance of an hypotheses in the absence of data.
"Prejudice" is having an opinion not supported by the preponderance of the data.
"Knowledge" is only found through the accumulation and analysis of data.
RE: Analisis of downhill pipeline
Independent events are seldomly independent.
RE: Analisis of downhill pipeline
this could be solve in minutes using stormcad
RE: Analisis of downhill pipeline
@zdas04 We have checked each pipe segment that changes size or slope and have found that some work as open chanel and others work as full pipe. I'm not sure if that is possible or undesirable.
@BigInch Will it be correct to asume that the flow backs up to the point where the pressure at the start of the full pipe segment is enough to compensate for the pressuro losses for the required flow?
@cvg Sadly, the pipe now has some segments that work as full pipe. But I'll keep StormCAD in mind for other situations.
Let me know if anyone wants to see the profile. We are checking a pipeline of 30inches that runs for almost 6Km that drops 150m and is required that it handles 2400m3/h.
Thanks for all the sugestions.
EloyRD
RE: Analisis of downhill pipeline
Not much slope, very high flow. I didn't run any numbers on it, but it looks like that will be tough, and if it will handle the flow, which I doubt, the fast velocity will need some pretty good erosion resistant material.
Independent events are seldomly independent.
RE: Analisis of downhill pipeline
RE: Analisis of downhill pipeline
David Simpson, PE
MuleShoe Engineering
"Belief" is the acceptance of an hypotheses in the absence of data.
"Prejudice" is having an opinion not supported by the preponderance of the data.
"Knowledge" is only found through the accumulation and analysis of data.
RE: Analisis of downhill pipeline
Independent events are seldomly independent.
RE: Analisis of downhill pipeline