IOSR Journal of Mechanical and Civil Engineering (IOSR-JMCE) e-ISSN: 2278-1684,p-ISSN: 2320-334X, Volume 17, Issue 2 Ser. III (Mar - Apr 2020), PP 09-24 www.iosrjournals.org DOI: 10.9790/1684-1702030924 www.iosrjournals.org 9 | Page Numerical and Experimental Study of a Centrifugal Pump with Varying the Outlet Short Blade Angle Abdullah.H.I.Aboelnil *1 ,Mohamed. A. Abdellatif 1 ,Ibrahim Shahin 2 , Mohamed.A.Moawad 2 ,Mohamed.F.Abd Rabbo 2 1 Mech. &Elect. Research institute (MERI), National water research center (NWRC), Cairo, Egypt 2 Mechanical Power Eng. Department, Shoubra Faculty of Engineering, Benha University, Cairo, Egypt Abstract: Around 20% of the world total energy consumed by pumps. Centrifugal pump is the most common type used in all industrial and agriculture application. The challenge is how to save the energy consumption due to pump work. Slip factor is the most important parameter which effect on the efficiency of the centrifugal pump. In the present paper, the performance of a centrifugal pump with specific speed 46 is studied numerically and experimentally and the slip factor is predicted numerically. The effect of adding short blades with varying the outlet blade angle of the shorted blades also is studied experimentally and numerically. The numerical result of two cases of the impeller, with and without short blades, has a good agreement with the numerical one. Adding short blade has a good effect on the slip factor magnitude which improved by 21 %. Also the total efficiency of the centrifugal pump increase by 1.9 %. --------------------------------------------------------------------------------------------------------------------------------------- Date of Submission: 14-03-2020 Date of Acceptance: 30-03-2020 --------------------------------------------------------------------------------------------------------------------------------------- Nomenclature σ Slip factor Ns Specific speed δ Deviation angle Q The pump discharge m 3 /hr β2B The ideal exit vane (flow) angle H The pump head m β2 The actual exit vane (flow) angle Ω The pump speed RPM Z The number of impeller’s vane Gk generation of turbulent kinetic energy ur vector fluid velocity in the rotating system σk,σɛ turbulent Prandtl numbers μ eff dynamic effective viscosity L Cord length of the main blade u vector fluid velocity in the stationary frame LR Cord length of the short blade k turbulent kinetic energy Qn Nominal pump discharge m 3 /hr ɛ dissipation rate d4 Volute out diameter mm μ laminar viscosity b3 Volute thickness mm μ t Turbulent viscosity tblad Blade thickness mm Ф impeller discharge flow coefficient, dimensionless Cm2/U  Density of fluid kg/m 3 I. Introduction The performance of pump is estimated by the dynamic of the fluid inside the pumps getting from the designing structure. The rotational element of the pump is called impeller which the most important part that effect greatly on the overall efficiency of the pump performance. The total head for the centrifugal pump is the resultant which can be estimated as the developed theoretical head, which the minus result between Euler’s equation, and hydraulic losses. The impeller with small number of blades does not guide the fluid flow properly and an additional mixing loss is occurred. When the blades number increase, the slip factor increase and the theoretical head of the pump increase, while too many numbers of blades get decreasing in the efficiency according to the increasing of blockage at inlet and the friction through the impeller passage. A method, which considers a type for modifications of increase the slip factor, theoretical head and also the efficiency developed by the impeller is using shorted blades that reduce the circulation near the impeller exit. The short blade is partial blade with a shorter in longitudinal length than the original blade and casted in the space between each two original blades. The characteristic curves of the impeller with and without splitter blades were studied experimentally to show the effects of lengths and the number of blades of the splitter blades on a deep well pump performance [1]. Positive splitter blade effects are not seen for the high number of blades and low blade discharge angle. However, adding splitter blades is useful for the impellers with small number of blades (z = 3 and 4). When the splitter blades with a length of 80% of the main blade length were added to the same blade number, the energy consumed by the deep well pump decreased.