An experimental study of volute influence on radial
flow-impeller performance was conducted by operating a
single impeller with three different sets of volute vanes.
In each case, over-all performance was measured and an
internal-flow study within the volute was made. The results
show that at their respective design flow rates the influence
of the volutes is least and the deviation of performance
from the free-impeller operation is small. At
off-design flow rates there are major changes in the impeller
performance resulting from the presence of the
volutes. Large real fluid effects, coupled with a nonuniform
velocity pattern at the impeller exit, result in a flow
through the volute that does not resemble a potential flow.
Even so, the fluid losses through the volute are comparatively small
