scholarly journals Research on Blade Thickness Influencing Pump as Turbine

2014 ◽  
Vol 6 ◽  
pp. 190530 ◽  
Author(s):  
Sun-Sheng Yang ◽  
Chao Wang ◽  
Kai Chen ◽  
Xin Yuan
Keyword(s):  
Hydraulic Loss ◽  
Distribution Analysis ◽  
Blade Design ◽  
Efficiency Improvement ◽  
Efficiency Curve ◽  
Loss Distribution ◽  
Performance Change ◽  
Blade Thickness ◽  
Numerical Research ◽  
Geometry Parameter

Research on the efficiency improvement of pump as turbine (PAT) is inadequate. Blade thickness is an important geometry parameter in blade design. To explore effects of blade thickness on the influence of PAT, numerical research on three different specific speeds of PATs with different blade thickness was carried out. Their performance changes with blade thickness were presented. Besides, the variations of hydraulic loss distribution with increasing blade thickness were performed. Theoretical analysis gives a reasonable explanation for the performance change. Results show thatPAT's flow versus efficiency curve ( Q-η) is lowered; flow versus head ( Q-H) curve and flow versus power ( Q-P) curve are increased with increasing blade thickness. The increase of Q-P is mainly attributed to the increase of theoretical head caused by increasing blockage of impeller inlet area. Hydraulic loss distribution analysis indicates that the total hydraulic loss within PAT is increased with increasing blade thickness. The increase of Q-H curve is a combined effect of the increase in theoretical head and the total hydraulic loss. The decrease of efficiency with increasing blade thickness indicates that the blade thickness of PAT should be as thin as possible if its strength could be met.

Effects of Blade Wrap Angle Influencing a Pump as Turbine

2012 ◽  
Vol 134 (6) ◽  
Author(s):  
Sun-Sheng Yang ◽  
Fan-Yu Kong ◽  
Hao Chen ◽  
Xiang-Hui Su
Keyword(s):  
Theoretical Analysis ◽  
Pressure Head ◽  
Hydraulic Loss ◽  
Impeller Blade ◽  
Loss Distribution ◽  
Performance Change ◽  
Shaft Power ◽  
Wrap Angle ◽  
Specific Speed ◽  
Blade Wrap Angle

A pump is not ideally designed to operate as a turbine. To improve the efficiency of a pump as turbine (PAT), the redesign of the PAT, according to the flow of the turbine, is required. The blade wrap angle is one of the main geometric parameters in impeller design. Therefore, an investigation into the blade wrap angle to the PAT’s influence can be useful. In order to understand blade wrap angle to the influence of the PAT, this paper numerically investigated three different specific speeds of PATs with different blade wrap angles. The validity of numerical simulation was first confirmed through a comparison between numerical and experimental results. The performance change of the PATs with the blade wrap angle was acquired. A detailed hydraulic loss distribution and a theoretical analysis were performed to investigate the reasons for performance changes caused by the blade wrap angle. The results show that there is an optimal blade wrap angle for a PAT to achieve the highest efficiency and the optimal blade wrap angle decreases with an increasing specific speed. A performance analysis shows the PAT’s flow versus pressure head (Q-H) and flow versus generated shaft power (Q-P) curves are lowered with the decrease of the blade wrap angle. The hydraulic loss distribution and theoretical analysis illustrate that it is the decrease of hydraulic loss within the impeller, together with the decrease of the theoretical head, that results in the performance decrease. The decrease of hydraulic loss within the impeller is attributed to the shortened impeller blade passage and the reduced velocity gradient within the impeller flow channel. With the decrease of the blade wrap angle, the slip factor of the PAT’s impeller is decreased; therefore, its theoretical head is also decreased.

Influence of Turbocharger Turbine Blade Geometry on Vibratory Blade Stresses

2018 ◽  
Vol 141 (2) ◽  
Author(s):  
Pavan Naik ◽  
Bernhard Lehmayr ◽  
Stefan Homeier ◽  
Michael Klaus ◽  
Damian M. Vogt
Keyword(s):  
Turbine Blade ◽  
High Cycle Fatigue ◽  
Pressure Field ◽  
Spanwise Direction ◽  
Blade Design ◽  
Centrifugal Forces ◽  
Baseline Design ◽  
Combined Stresses ◽  
Blade Thickness ◽  
Turbine Blade Design

In this paper, a method to influence the vibratory blade stresses of mixed flow turbocharger turbine blade by varying the local blade thickness in spanwise direction is presented. Such variations have an influence on both the static and the vibratory stresses and therefore can be used for optimizing components with respect to high-cycle fatigue (HCF) tolerance. Two typical cyclic loadings that are of concern to turbocharger manufacturers have been taken into account. These loadings arise from the centrifugal forces and from blade vibrations. The objective of optimization in this study is to minimize combined effects of centrifugal and vibratory stresses on turbine blade HCF and moment of inertia. Here, the conventional turbine blade design with trapezoidal thickness profile is taken as baseline design. The thicknesses are varied at four spanwise equally spaced planes and three streamwise planes to observe their effects on static and vibratory stresses. The summation of both the stresses is referred to as combined stress. In order to ensure comparability among the studied design variants, a generic and constant excitation order-dependent pressure field is used at a specific location on blade. The results show that the locations of static and vibratory stresses, and hence the magnitude of the combined stresses, can be influenced by varying the blade thicknesses while maintaining the same eigenfrequencies. By shifting the maximum vibratory stresses farther away from the maximum static stresses, the combined stresses can be reduced considerably, which leads to improved HCF tolerance.

Identification of Replica Modes in Integrally Bladed Rotor

2011 ◽  
Vol 110-116 ◽  
pp. 2348-2353
Author(s):  
Rana Noman Mubarak ◽  
Jen Yuan Chang
Keyword(s):  
Natural Frequencies ◽  
Low Frequency ◽  
Free Vibrations ◽  
Forced Response ◽  
Design Parameters ◽  
Blade Design ◽  
Blade Angle ◽  
Blade Thickness ◽  
Symmetric Rotor ◽  
Bladed Rotor

Effects on structure designs on free vibrations of integrated bladed rotor (IBR) have been conducted in this research through finite element simulations. Migration of natural frequencies is characterized through parameter studies considering changes of blade angle and blade thickness on an underlying uniform axis-symmetric rotor. Recurring coupled repeated doublet modes, defined as replica modes, has been observed in this study by characterizing blade’s vibrations in-phase or out-of-phase to disk’s vibrations. Veering and cluster of replica modes’ natural frequencies are observed with respect to the blade design parameters. Fourier content for low frequency replica component is found to be sensitive and tunable to blade angle design, which has implications on forced response of spinning IBR in engineering applications.

Head Curve of Noncavitating Inducer

2011 ◽  
Vol 133 (2) ◽  
Author(s):  
Wen-Guang Li
Keyword(s):  
Experimental Data ◽  
Correction Factor ◽  
Reliable Method ◽  
Hydraulic Loss ◽  
Blade Angle ◽  
Singularity Method ◽  
Blade Thickness ◽  
Hydraulic Design ◽  
The Mean ◽  
Good Agreement

In the inducer hydraulic design, one significantly important task is to estimate its noncavtating head; however, there is not a matured and reliable method for this presently. In this paper, a method was made for predicting the inducer head curve. The method was based on a singularity method and a hydraulic loss model with a variable correction factor. The blade thickness blockage effect on the flow was taken into account. The method was validated with the experimental data of the existing 17 inducers found in references. Moreover, the curves showing the relation of the correction factor with the mean blade angle at tip for two- and three-bladed inducers were established. The method can achieve a very good agreement with experimental observations. Furthermore, the flow field calculated by the method may be instructive to the engineers of inducer hydraulic design.

Performance Improvement Versus CPW and Loss Distribution Analysis of Slow-Wave CPW in 65 nm HR-SOI CMOS Technology

2012 ◽  
Vol 59 (5) ◽  
pp. 1279-1285 ◽  
Author(s):  
Xiao-Lan Tang ◽  
Anne-Laure Franc ◽  
Emmanuel Pistono ◽  
Alexandre Siligaris ◽  
Pierre Vincent ◽  
...  
Keyword(s):  
Performance Improvement ◽  
Slow Wave ◽  
Cmos Technology ◽  
Distribution Analysis ◽  
Loss Distribution ◽  
Soi Cmos

scholarly journals Automotive Package Lead Pullback Elimination Using Monte Carlo Analysis for Determining Leadframe and Blade Design

2021 ◽  
pp. 97-107
Author(s):  
Jefferson S. Talledo ◽  
Patricio A. Cabading Jr. ◽  
Rogelio A. Real
Keyword(s):  
Monte Carlo ◽  
Traditional Approach ◽  
Tolerance Analysis ◽  
Monte Carlo Analysis ◽  
Design Solution ◽  
Inspection System ◽  
Blade Design ◽  
Blade Thickness ◽  
Analysis Technique ◽  
Final Design

This study focuses on eliminating the lead pullback problem in an automotive quad flat no lead (QFN) package in order to meet the non-negotiable requirement to have a solder wettable or solderable lead sidewall. It involves using a non-traditional approach of Monte Carlo tolerance analysis to determine the final leadframe and singulation blade design solution. It was found out that the zero lead pullback could be achieved by reducing the leadframe lead to lead distance from 0.275 mm to 0.225 mm and increasing the blade thickness from 0.325 mm to 0.350 mm. Actual results from 10 line stressing lots all showed zero pullback validating the effectiveness of the final design and the use of Monte Carlo tolerance analysis technique. Costly investment for a lead pullback inspection system was avoided and the 100% manual inspection eliminated.

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