Profile Equations For Blade And Numerical Simulation Of Flow Field In Screw Centrifugal Pump

With the development of technology and economy, hydraulic machinery is widely used to transport all kinds of solid matter in many fields. As a new kind of impurity pump, screw centrifugal pump combines the advantages of screw pump and centrifugal pump, and the special structure can make use of their advantages sufficiently. Compared with the traditional impurity pump, screw centrifugal pump has a series of strong points, such as: good through-flow condition, not easily blocking, little abrasion in overflowing parts, high efficiency, longevity of service, low cost and good accommodation.According to the impeller structure of screw centrifugal pump, profile equations for impeller blade of screw centrifugal pump are constructed. Then based on these equations a 150×100ZN -32 screw centrifugal pump impeller is designed. The practice proved that the new design method of screw centrifugal pump blade using in this paper can avoid some shortcomings, such as the manual mapping being miscellaneous and dependence experience entirely in unitary theory hydraulic design method. It is significant to the CAD, the enhancement of design precision, drawing blade fast and the numerical simulation of the flow field 3D in the screw centrifugal pump.In this paper, turbulent Reynolds equations, standard k-ε turbulent model and sliding mesh are used. 3D steady turbulent flow in screw centrifugal pump of single blade and double blades are simulated by using FLUENT. And 3D unsteady turbulent flowing in the double blades is simulated too. The results of the simulation show that using these models can reflect the distribution of pressure and velocity in the pump. In order to proof the feasibility of using profile equations for screw centrifugal pump's design, the 150×100LN-32 screw centrifugal pump impeller which is designed on this method is simulated in this paper. In order to obtain the external characteristic curves of the single blade screw centrifugal pump and the double, many operating computation to them have been carried on, compared the curves of the single and double blades pump transported the water under the same operating conditions, and studied the influence of single and double blades to the pump external characteristic. Through the simulation the double blades screw centrifugal pump in 3D unsteady flow, unveiled the disturbance between the static and dynamic flow of the impeller and the volute generates the unsteady influence in screwcentrifugal pump. And the pressure oscillation is obtained on the screw centrifugal pump flow channel exports. At the same time, it is discovered that the fluctuation range of outlet pressure is large. Using the results of the simulating the flow of the double blades screw centrifugal pump transport the two phase currents, the different solid phase density, different pellet particle size operating mode internal pressure are studied. The results of research can offer some information to the screw centrifugal pump blade's design and the performance improvement.