While CFD is considered a valuable and important tool
for enhancing the value of physical model studies,
it is still far from being able to replace physical models
for pump intake modeling.
impeller. A standardized system was
also established to classify free and
subsurface vortex activity. Acceptable
preswirl, velocity distribution, and
vortex activity were defined based on
experience gained over many years
comparing physical models and
prototype operation. A physical model
study conducted in accordance with the
HI criteria by laboratories experienced
with pump intake modeling should
provide the same results, regardless of
the organization.
About 15 years ago, Alden and
others started experimenting with the
use of CFD for pump intake modeling.
CFD is unreliable at predicting the
time-dependent unstable vortices that
can be characteristic of pump intakes;
however, the allure of a faster and
more cost-effective modeling approach
was significant. In the ensuing time,
computers have become much more
powerful, and CFD model codes and
methods have improved, albeit at a
slower pace.
Among civil engineering firms,
Alden is one of the largest users of CFD
in North America based on number of
licenses in use. Alden also conducts 10
to 15 physical models of pump intakes
each year, uniquely positioning Alden
to conduct ongoing comparisons
between CFD and physical model
results. The research to date has failed
to produce reliable CFD results for
predicting pump intake performance.
The Present
In 2016, the HI invited leading CFD
engineers from around the world to
participate in a forum regarding the
state of the art in CFD modeling of
pump intakes. The modelers present
all used a variety of CFD codes and
turbulence models, including large
eddy simulations (LES) run on
wateronline.com
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