| The centrifugal pump is one kind of machines are widely used in many fields.According to statistics,about 20% of national generating capacity is consumed by the pump each year in China.At the same time,the pump efficiency has some discrepancy between our country and advanced developed countries.It's very important and significant to improve the efficiency of the pump in order to develop the national economy and reducing the energy consumption.Impeller is a important component of centrifugal pump.The blade shape is one of the key decisive factors of pump performance.At present,the speed coefficient method is used for design the impeller.The conformal transformation is often used to design the blade. The traditional method of drawing expanding streamline on the orthogonal grid is mostly depend on the designer's experience.These methods not only with low accuracy,but also hard to control the shape of the streamline and blade angle in the general.It's has a lot of randomly to design centrifugal impeller by conformal transformation.Firstly,the angleγof the impeller blade outlet side has not be certain.Secendly,the blade wrap angle hasn't be fixed too.Thirdly,the variational rule of the streamline blade angle is also uncertain.Therefore,it is necessary to study the blade profile,looking for more accurately method to determine the blade profile .In this paper,the angleγand wrap angle are studied to find the influence of the blade profile of centrifugal pump.1.The calculation formula of blade wrap angle is given.The quartic Bezier curve was used for design the blade expanding streamline,and the control method of these curves is proposed.The impeller blade expanding streamline could be ensured smoothly and monotonically,and the streamline was easier to be controlled.The drawing efficiency is improved.The methods used in design the impeller is feasibility.2. Though numerical simulating the designed pump and analyzing the internal flow field, we can know the conclusion as follow: The relative velocity on the pressure surface of the impeller is small in the vane, and on the suction surface is relatively large. The change of relative velocity from the pressure surface to the suction surface is relatively great. There isn't boundary layer separated in the impeller's vane. The static pressure and the total pressure increased gradually from the inlet to the outlet of the impeller. The static pressure and the total pressure in the impeller outlet decreased with the increase of the flow quantity.3.The angleγis studied in the same conditions. The ZA150-315 are designed three angleγdegrees: 62°,76°,90°which specific speed is 98;The ZA150-200 are also designed three angleγdegrees: 69°,79°,90°which specific speed is 188;The TTMC-125 are designed three angleγdegrees: 64°,77°,90°which specific speed is 78.The FLUENT6.3.26 is applied to numerical simulate centrifugal pumps.The calculated resultes show that:The performance of ZA150-315 impeller which angleγis 76°is better than 62°and 90°; The performance of ZA150-200 impeller which angleγis 69°is better than 79°and 90°; The performance of TTMC-125 impeller which angleγis 64°is better than 77°and 90°. The performace curves are analysed,the resulte show that every impeller has a right angleγ.4.With ZA150-315,for example.Under the condition of invariable in meridional plane,The wrap angle are determined for 180°,195°,210°by the method.The impeller's hydraulic model was got separately by hydraulic design.The following conclusions are found by simulation,Warp angle of 195°of the impeller which performance is better than the other two impellers.the resulte also show that every impeller has a right blade wrap angle to make the impeller has best performance.
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