Pump Intake Design ANSI HI 9.8: 1998.pdf
6 acknowledgements trinity river authority of texas. ansi/hi (hydraulic institute) pump standards, 1998 pumping station design,3 rd edition editor-in-chief: garr m. jones, p.e. co-editors: dr. robert l. sanks, ph.d., p. dr. george tchobanoglouos, ph. bayand e. bosserman ii, p. (quality control) dr. joel e. cahoon, ph., montana state university
Pump Intake Design ANSI HI 9.8: 1998.pdf
the university is doing the research as part of the master of science degree, with an additional responsibility to advise students of appropriate hydraulic instrumentation. the collaboration began with the university's funded research to design the trinity river diversion dam that included the cfs pump station.
the students assisting were a monitoring engineer, a mechanical engineer, and a hydrogeologist. the students got the opportunity to work on the project to design the pump intake flow at the cfs pump station on the trinity river diversion dam. the students learned how to use a cfd model to simulate the pipe flow downstream of 90 elbows and upstream of a pump inlet.
this study is expected to contribute to the work of ansi/hi 9.82012, where recommendations to improve the current design of suction intakes are required in order to avoid the worse designs of the 1998 edition. nevertheless, although the pipe length and the elbow sizes were similar to the ones in the norm, the pump suction flow was approximately 27% lower.
the ansi/hi 9.8 ( 2012 ) study showed that all pumps fell outside of the recommended criteria, mainly because the variations of the velocity fluctuations along the cross section were more than 10% of the average velocity along the cross section. additionally, no elbows were considered as not flow-disturbing fittings, as assumed by the norm. in the present study, the best pumping design and design acceptance criteria in the 1998 edition were compared. flow disturbances caused by elbows or pumps were measured as the mean swirl angle. first, the dimensionless critical flow distance parameter, e, along the long radius elbow was calculated as mathop smallint limits_0^t eleft( t right)textdt (where u is the mean velocity and t is the averaging time). second, the swirl angle at the elbow was extracted from the flow field, using the geometry of the elbow. the following criteria were applied to the studied cases: (i) swirl angles must be less than 5; (ii) time-averaged velocities at the pump suctionin a piping system shall be within 10% of the cross-sectional area averagevelocity,..