الفهرس 
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Abstract
The pr eaeut work is carried out to investig.Jte the eCfcct or
var Lat Iou oC impeller valle curvature, speed and water flow r a t e
on the perCormance of a water ring vacuum pump.
1\ test rig was designed. It contained calibrated measuring
instruments to determine the pump speed, suction and delivery
preasures, mass flow r<lte and br<lke power illPut.
The pump was tested at three different operatillg speeds o(
1130, 1580 and 1750 rpm and for three different water flow rates,
oC a,u and IG lit./mill.
Five different impeller vane shapes were tested. The vanes
were designed to have the same chord length but different camber.
1\n analysis was made to the characteristics of each Impe l l e r
at different speeds and different water flow rates. I\lso the
performance characteristics of different impellers were analysed
for the same speed and the same water flow rate.
The followings are the major conclusions of this study :
1- The performance characteristics of the water ring vacuum pump
showed a marked dependence on the vacuum percentage developed
by the pump.
2- Every rotational speed, water flow rate and blade curvature re!lulted in a difCp.rent characteristic curve.
J- The optimal efCiciency and the maximum fluid power were
realii:ed inside the stable region of suction capacity for each
characteristic curve.
4- /\back flow problem was noticed at low speeds of rotation
(1130 rpm). Consequently, it is not advised to run vacuum
pumps at such low speeds.
5- The vane curvature variation had a great effect on the water
ring vacuum pump perCormancp.. Within the tested range,
increasing the blade camber improved the pump perCormance alld
had an increasing effect 011 the operating parameters. These
are suction capacity, vacuum percentage, fluid power and
efficiency.
6- The water flow rate variation had also a remarkable effect 011
the pump pe rt ormance . The increase of water flow rate improved
both the sealing and the cooling o( dif ferent pump components.
l\ccordingly, this improved the operating parameters. lIowever,
the brake power is found to be nearly independent of water
flow rate variation.
7- The speed variation had also a noticeable effect on pump
performance. As the speed increased, all the values of
operating parameters also increased; except the efficiency
which decreased after exceeding a certain speed limit. This
limit changes with water flow rate and vane curvature.