This is due to air leaving and reentering the impeller inlet (recirculation), changes to the angle of air leaving the impeller blade
(slip), shearing of air between the rotating impeller and adjacent stationary walls (disc friction), and other real flow effects not considered in the ideal assumptions used to derive Equation 16 .
Considering the relative velocity of the mixture (water + sediment) passing through a certain area of the impeller blade
, a relative sliding distance (S) was estimated according to Eq.
to investigate the effect of the impeller blade
angle and its shape on regenerative pump performance.
In the stator frame as well, the pressure field attached to the rotating impeller blade
induces incoming flow field distortions .
Traditional centrifugal compressors with design capacities of 967kW (275 ton) and less also begin to suffer a degradation of full load efficiency due to the smaller impeller blade
spacing which increases the flow friction losses (Stoecker and Jones 1982).
where [dh.sub.inc] are impeller and diffuser incidence flow losses, [dh.sub.Nf] are the diffuser friction losses, [dh.sub.if] are the impeller friction losses, [dh.sub.bld] are impeller blade
loading losses, and [dh.sub.mix] are impeller fluid mixing losses.
Moreover, the geometry shape of impeller blade
has strong effect on pump performance, including vibrations.
Our attention is focused on the effects of impeller rotational speed, fluid rheology and impeller blade
The velocity streamlines of the impeller blade
surface and the impeller inlet at 0.75[Q.sub.BEP] are shown in Figure 11.
The shroud has its inner contour shape in such a way to match the impeller blade
tip from the inlet to the exit of the impeller.
For example, based on the research analysis, product development incorporating an impeller blade
with an inwardly disposed bulge or bulge defined by d/d = T/D would establish propriety of the overall design that could maintain exclusivity on the market.
The distance from the surface of the liquid to the centreline of the impeller (submergence, S) was varied from the impeller blade
height to half of the total liquid depth (0.01 m < S < 0.12 m).