## What is/are Impeller Blades?

Impeller Blades - The dependence of the efficiency of a centripetal turbine on the profiles of the blades and the radial dimensions of the nozzle apparatus and the impeller, as well as on the length of the impeller blades is investigated.^{[1]}The radial force on the impeller decreases gradually with the increase of the flow, the distribution is hexagonal or hexagonal shape, and the number of impeller blades is the same.

^{[2]}The time-domain waveform of outlet of the inlet passage at the pressure pulsation monitoring point has obvious periodicity, and the dominant frequency of the monitoring point is four times the rotation frequency, which corresponds to the number of impeller blades.

^{[3]}The results show that this method can well convert the free-form surfaces of the impeller blades into ruled surfaces.

^{[4]}The impeller blades of ceramic slurry pumps are usually very thick for the purpose of prolonging the service life.

^{[5]}The shape of impeller blades of a centrifugal pump affects the best efficiency point (BEP), and splitter blades improve the pump performance at BEP.

^{[6]}A moving reference frame is applied to simulate revolutions of impeller blades for a waterjet propulsion system.

^{[7]}The results show that the pressure fluctuation has strong periodicity, and the fundamental frequency of the pressure fluctuation on the inlet and outlet surfaces is the blade passing frequency and the blade passing frequency respectively, which means the rotation of impeller and rotor stator interaction (RSI) phenomenon between impeller blades and guide vanes are the origin of hydrodynamic pressure fluctuation.

^{[8]}High risk of erosion exists at the outlet part of impeller blades and the inlet part of diffuser blades.

^{[9]}In the present study, an erosion analysis of an industrial pump’s casing and impeller blades has been performed computationally.

^{[10]}The robustly designed ‘S-shape’ impeller has a continuously connected impeller blade, which improves the structural strength of the impeller blades as well as pump performance.

^{[11]}A non-periodic pattern of flow and cavitation bubbles between the impeller blades, which is caused by the inlet pipe bending, is also well reproduced by the model.

^{[12]}Also, the interaction between the impeller and volute tongue region is actually according to the impeller blades’ relative position concerning the tongue region.

^{[13]}Therefore, the purpose of this study was to analyze the role of the number and angle of impeller blades on the performance (discharge and discharge pressure) of centrifugal pumps based on experiments and simulations.

^{[14]}The comparisons across cases demonstrate that the radial gap between the trailing edge of the impeller blades and the leading edge of the diffuser blades has a more profound influence on pressure fluctuations, compared to the angle of incidence on the diffuser blades of the flow coming from the impeller.

^{[15]}Aerated cavities behind the impeller blades in stirred tanks affect the power transferred to the liquid that in turns affects heat and mass transfer, thus the development of fully predictive simulation methods to detect the formation of cavities, their size and structures is of paramount importance for an effective simulation of aerated reactors and bioreactors.

^{[16]}Numerical simulations are performed to analyze the effect of the ratio of the number of guide vane blades to the number of impeller blades (vane number ratio) on the turbine performance and flow field.

^{[17]}First, increasing the number of the impeller blades was intended to enhance the bounding effect that the blades imposed on the fluid.

^{[18]}The calculations of a high specific speed torque-flow pump of three different design configurations of the impeller blades were performed.

^{[19]}Research methods are based on the experimentally proven hypothesis about the dependence between the control flow rate on the impeller blades and the position of the rear critical points of the blades.

^{[20]}The pump design can also be made more efficient by optimizing the design of the impeller blades.

^{[21]}Eight three-dimensional models of pumps with varying outlet angles of the straightener blades and varying lengths of the impeller blades were used in the study.

^{[22]}This is because an increase in the impeller rotation speed causes vortex deformation, whereby its bottom part approaches the impeller blades where the turbulent surface oscillations reach maximum amplitudes.

^{[23]}Type 3 vortices grew with the wider diffuser because of the higher pressure-recovery, which caused the serous loading to the impeller blades.

^{[24]}This study was performed to investigate the effects of changing the number of impeller blades in the Head and the Efficiency of the pump running at constant and varying speeds.

^{[25]}The following conclusions were made from the comparison of relative velocity vector field: first, the wear on the outlet of blades can be mitigated effectively by reducing the outlet angle of impeller blades; second, the pump with a double-arc-shaped profile had a more uniform and stable flow field distribution and higher performance than that with a single-arc profile; and finally, the “jet–wake” structure can be improved significantly by using impellers with long and short blades, resulting in a remarkable reduction in energy loss and improvement in pump efficiency.

^{[26]}One of the ideas is to use winglets (super-vortex) on the tip of the impeller blades.

^{[27]}The results show that bubbles move to the hub and a homogeneous bubble size distribution can be observed due to the rotational effect and stirring action of the impeller blades.

^{[28]}That is, the impeller blades of the compressor act as the motor rotor.

^{[29]}The technologies and results of an experimental determination of residual stresses in the impeller blades of a hydraulic unit of the Krasnoyarsk hydroelectric power plant obtained through technical diagnostics beyond the projected periods of use are presented.

^{[30]}Several catastrophic events have occurred in service due to the fibbers clog the gap between the impeller blades and the pump casing.

^{[31]}To further analyze the dynamic stress characteristics of impeller blades of axial-flow pumps, a bidirectional fluid–structure interaction (FSI) was applied to numerical simulations of the unsteady three-dimensional (3-D) flow field of the whole flow system of an axial-flow pump, and the gravity effect was also taken into account.

^{[32]}The influence of the gap between the impeller blades and the body is estimated.

^{[33]}It is a continuous process of solving the inverse and direct problem of gas-dynamic design, profiling the flow section with subsequent analysis of the rational velocity distribution of an inviscid flow on the impeller blades on axisymmetric streamline surfaces.

^{[34]}The highest turbulence kinetic energy dissipation rates are observed close to the impeller blades and stator walls where the radial jet strikes the stator walls periodically.

^{[35]}Five factors, which include four geometrical factors (submergence, impeller-to-tank ratio, number of impeller blades and baffling mode) and a physical factor (liquid viscosity) were considered.

^{[36]}Throughout the blade optimization of the ‘S-shape’ blade, it is found that the chief influence on the pump efficiency is the number of the impeller blades.

^{[37]}Further analyses focusing on the interactions between the impeller blades and fluid rheology is needed to improve laminar mixing in stirred vessels by impeller modification.

^{[38]}The operation of a reversible pump-turbine in condenser mode requires to dewater the impeller by closing the guide vanes and injecting compressed air in the draft tube cone to reduce the friction torque on the impeller blades.

^{[39]}In particular, the diffusion of oxygen through the water free-surface both in the vaneless gap between the impeller blades and the closed guide vanes and in the cone of the draft tube is investigated.

^{[40]}Profiles were set on the pressure side and suction side of impeller blades at the distances of 0.

^{[41]}In this current study, the transient numerical calculations using CFD are carried out under different number of impeller blades for the flow field within a centrifugal pump under single-phase and cavitation condition.

^{[42]}A new design of a liquid ring vacuum pump is developed providing kinematic closure of the rotating sleeve blades and impeller blades.

^{[43]}The wear volume as a function of the relative velocity of the mixture in relation to the impeller blades was estimated mathematically.

^{[44]}The distribution law of the equivalent stress on the surface of the impeller cover plate is that the equivalent stress value changes periodically along the circumferential direction of the impeller, and the number of change cycles is equal to the number of impeller blades.

^{[45]}Results of the comparative study showed that cavitation first occurred at the suction leading edge on the impeller blades and attached cavitation observed on the impeller blade at the lower suction head in pump mode; however, for the turbine mode, the development of vortex cavitation happened at the runner outlet near thetrailing edge on the impeller blades.

^{[46]}Based on the principle of bionics and with MP80-160 single-stage single-suction centrifugal pump as a model, the current study adopted Eulerian model to carry out numerical simulation by building the pit-type non-smooth surface on the impeller blades.

^{[47]}The impeller blades have been designed by varying the semi-cone angle.

^{[48]}The obtained results indicated the existence of fundamental frequency corresponding to the speed of rotation times the number of impeller blades and of the whole series of harmonics of higher frequencies.

^{[49]}In the paper, the device of the centrifugal pump as a technical system is divided into the following main structural subsystems: impeller blades, impeller disks; housing; pressure pipe and suction pipe.

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## Compressor Impeller Blades

To check the aerodynamic appearance of the centrifugal compressor impeller blades, we must change the impeller dimensions and focus on changing axial length, but when changing the blade numbers, the model that improved efficiency and power at the same time introduced a design with a 0.^{[1]}Centrifugal compressor impeller blades inevitably suffer from manufacturing uncertainties.

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## Engine Impeller Blades

During the rotation, aero-engine impeller blades are subjected to the alternating load of high frequency, low stress and small strain, so it is effortless for the impeller blades to enter the stage of very-high-cycle fatigue (VHCF).^{[1]}Due to its good cutting performance in titanium alloy machining, integral end mills are more and more used in machining aero-engine impeller blades.

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