الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Around 20% of the world total energy consumed by pumps. The centrifugal pump is the most common type used in all industrial and agriculture application. More efficiency of centrifugal pump more energy saving, the most important parameter
effect on the total efficiency for the centrifugal pump is the slip factor, which is the relation between the actual and ideal velocity leaves the rotor part(impeller) of the centrifugal pump. Almost of old ways for estimating the value of slip factor are depend on practice formula or very complicated measurement, which loss time and money, also these ways didn’t study how to estimate the value of the slip factor if the design parameters are changed, such as adding short blades to the main blades
of the impeller. The present study present a new general way for estimating the slip factor value using CFD results for the centrifugal pump simulation model. Fourteen case of centrifugal pump with different specific speed, from 10 to 75 step
5, are simulated in the present study. The slip factor value is estimated from the numerical results for all simulated cases. Three cases of specific speed 29, 41, and
46 are study numerically and experimentally to verify the numerical results of the present simulation model and get a good agreement with the experimental results.
Anew relationship is modified between the slip factors and the specific speed for the centrifugal pump. Shorted blades are added with varying the outlet blade angle for the pump with specific speed 46. The effect of adding short blades is study
numerically and experimentally. Varying the outlet blade angle for the shorted blades β2 for this case from 21 degree to 20, 19, and 18 degree is study numerically and experimentally by casting the original impeller and a new modified four impeller after adding the short blades with varying them out blade angle. The numerical results for adding short blades with angle β2 =21º show the total head
increases by 15 % at the nominal flow and 2900 RPM. The total head improved
with 16%, 17.5%, and 17.9% when the β2 changed to 20º, 19º, and 18º respectively at the nominal flow and 2900 RPM. The values of slip factor of modification impellers improved from 0.7 for case with no short blades to 0.82, 0.83, 0.85, and 0.86 for case β2 =21º, 20 º, 19 º, and 18 º respectively. Experimentally, the short blade improve the total head by 1.6%, 2.7%, 3.2%, and 3.2% for case β2 =21º, 20 º, 19 º, and 18 º respectively at the nominal flow and 2900 RPM.