Papers by Keyword: Impeller

Abstract: The milling of blade surfaces has been treated in different works, with focus on tool type, process and system conditions, CNC programs, simulation for 3D machining, etc. This paper presents some basic theoretical and practical aspects related to the milling of blades and other associated surfaces of parts like rotors/ impellers, which are found in components of aviation, industrial turbo engines or turbochargers. The relevant analyze has been performed concerning the distinction of specific surfaces of impellers, the distinction, basic relations and determination of critical geometrical parameters associated to impeller and, correspondently, to the milling tool, as well the geometrical parameters for adjusting relative position of certain system parts.

Abstract: The article presents the results of experimental investigations of rotor wheels supersonic microturbines with a large angle of rotation of the flow. The characteristics of the studied rotor wheels. The analysis of the results of the study ratio speed of rotor wheels, depending on the Mach number. Recommendations for the design working wheels microturbines operating at high supersonic gas flow rates.

Abstract: This article shows the dependence of high frequency torch (HFT) plasmatron parameters on external mode settings. The optimal operation of the plasma stand is achieved experimentally; the numerical characteristics of this mode are calculated. Based on the burning indicators of the combustible waste percentage, the possibility of using plasma stand for disposal of these wastes was concluded.

Abstract: The effects of blade thickness on impeller performance is seldom considered when design the low specific speed centrifugal pump and only considered crowding coefficient when use the speed coefficient method calculate the head of the impeller was designed. It was didn't consider the fundamental relationship how leaf thickness and low specific speed centrifugal impeller performance effect each other. The three-dimensional of flow area would have large influence if the leaf thickness changes . Here the best true thickness of the low specific speed centrifugal impeller blade was obtained though study how the thickness of blade influence on the performance of low specific speed centrifugal pump.

Abstract: For a centrifugal fan impeller the blade shape can be defined using two parameters: the blade angle and the blade width. There are different design methods depending on the assumption made on both the blade width and the blade angle. In this paper four design methods are presented: constant blade width and variable blade angle; hyperbolic blade width and variable blade angle; hyperbolic blade width and constant blade angle; linear blade width and variable blade angle. The sequential algorithm for solving the characteristic system of equations, which defines the blade geometry, is implemented in a MATLAB script file, for which principal code lines are explained. In the solving process of the characteristic system of equations for all four design methods considered, different relationships for relative velocity are obtained. The comparative graphical analysis of impeller blades obtained by all of the four design methods, as well as the blade geometry parameters is presented.

Abstract: The article reviews some questions regarding replaceable hydraulic parts (RHP) for pumps with spiral volute. A range of optimal pump parameters achievable using RHP is considered.

Abstract: High cycle fatigue behavior of the compressor impeller is investigated. On the basis of numerical calculations of the stress-strain state of wheel the prognosis of life time is done. The results show relations between the number of cycles to failure and maximally possible stresses and displacements. Relation of cumulative fatigue damage is researched depending on the number of cycles for the different modes of vibration on resonant frequencies.

Abstract: Research of centrifugal pumps’ workflow through their modeling is made. The methods of modeling such processes are viewed: by traditional numerical method and by proposed purely electrical methods of modeling. By comparing modeling results with test results the adequacy of modeling by purely electrical methods is proved.

Abstract: The thixocasting technology is chosen to produce the turbocharger impellers as it is capable of producing castings with high precision dimension, free of oxide and shrinkage porosity defects and therefore long service life. The thixocasting turbocharger impellers have the similar mechanical property to those produced by forging and machine processes, but much less costs. In the thixocasting process, the semisolid slurry with certain solid fraction is injected into mould at a high speed. Since high viscosity and thixotropic characteristics, the semisolid slurry reveals unique flow condition and characteristics in the filling process. So, its very desirable for the die design, process optimization, and defect control to visualize the high-speed filling process of semisolid slurry by numerical simulation. In this paper, several commonly used viscosity models for semisolid slurry are analysed. The Power law cut-off model (PLCO) model is selected to simulate the filling process in the thixocasting process of the impellers of 319s alloy, compared with actual results by partial filling testing. The causes of the casting defects are also analysed, indicating that the simulation results can accurately reproduce the filling process of semisolid slurry, and PLCO model is a successful choice for simulating the filling process of semisolid slurry with high solid fraction.

Abstract: The method of computational fluid dynamics (CFD) is used to three-dimensional numerical simulation for the fluid flow process of ammonium persulfate crystallizer. By using standard model, this paper respectively simulated the flow field within the crystallizer in the impeller installation height of 1.2 m while stirring speed is of 60 r/min, 100 r/min and 200 r/min; and simulated the impact of the flow field inside the crystallizer when the stirring speed of 100 r/min and impeller installation height respectively is of 0.7 m, 1.2 m and 1.7 m. That calculation results show that: the velocity gradient is mainly concentrated in the area of internal draft tube and paddle around. With the increase of impeller speed, the flow velocity of the fluid within the crystallizer corresponding increases; and the energy also gradually decreases from mixing impeller to the settlement zone with the loss of the installation height, and the kinetic energy in the bottom of the crystallizer is reduced. Considering the energy and crystallization effect, selection of mixing speed of 100 r/min or so and installation height of about 1.2 m is more appropriate.