The Impact of Balance Hole Radial Position of Centrifugal Pump on Axial Force and External Characteristics

2011 ◽  
Vol 130-134 ◽  
pp. 1691-1695 ◽  
Author(s):  
Jin Jing Zhao ◽  
Jie Gang Mu ◽  
Shui Hua Zheng ◽  
He Quan Lu ◽  
Hui Wang
Keyword(s):  
Centrifugal Pump ◽  
Experimental Research ◽  
Axial Force ◽  
Radial Position ◽  
Good Effect ◽  
Radial Location ◽  
The Impact ◽  
The Relationship ◽  
External Characteristics

In this paper, the method of balancing the axial force with balance hole is studied based on the combination of CFD and experimental research. The relationship between the radial position of balance hole and the effect of axial force and external characteristics of the pump is in-depth studied. Research shows that, there are certain laws for the effect of the balance hole location to the axial force and the external characteristics: the overall pressure of the balance chamber and the axial force decrease with the decrescence of the balance hole radial location, which could get good effect on balancing axial force. But the head and efficiency decreased.

Simulation and Experimental Study on the Impact of Breadth of Back Blade on Axial Force Balance

2011 ◽  
Vol 130-134 ◽  
pp. 1568-1572
Author(s):  
Hui Wang ◽  
Jie Gang Mu ◽  
Miao Yin Su ◽  
Shui Hua Zheng ◽  
Jin Jing Zhao ◽  
...  
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Experimental Study ◽  
Axial Force ◽  
Three Dimensional ◽  
Force Balance ◽  
Simulation And Experiment ◽  
Simulation Results ◽  
The Impact ◽  
The Relationship

The paper studies the relationship between axial force and breadth of back blade by numerical simulation and experiment. On the basis of the RNG k-ε turbulence model and technology of compact local grids and regional computing, three dimensional numerical simulations to 100HZ165-250 centrifugal pump with various breadths were carried out. Through comparing and analyzing of the flow field, it can be seen that the axial force reduces with the increase of the back blade breadth. After that, the simulation results were verified by the experimental data got from different test devices, and it shows that the conclusions are reliable.

scholarly journals Study on the Relationship between Wear and Flow Characteristics of a Centrifugal Pump at Different Mass Concentrations

Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 988
Author(s):  
Zhongqian Jiang ◽  
Xiaodong Zeng ◽  
Yi Li
Keyword(s):  
Flow Field ◽  
Centrifugal Pump ◽  
Experimental Research ◽  
Performance Test ◽  
Gradient Theory ◽  
Particle Movement ◽  
Discrete Phase Model ◽  
Energy Gradient ◽  
The Relationship ◽  
Mass Concentrations

In order to study the wear characteristic of a centrifugal pump at different mass concentrations, simulation and experimental research were carried out. The simulation was based on the DPM (discrete phase model) to complete the coupling of particles and the flow field. The experimental research included a performance test and a wear test. Through the comparison of the simulation and experimental research results, the relationship between the particle movement and the wear was analyzed, and the flow field was analyzed through the energy gradient theory. The energy gradient and the particle movement were combined to explain the wear characteristics. When the particles entered the impeller flow area, they directly hit the leading edge of the blade and the hub wall. The particles were sinking due to the flow field, which caused the particles to accumulate near the hub and the pressure surface. These places were at the most severely worn wall. The farther away from the axis the position was, the greater the relative velocity difference between the particles and the wall was, so that wear occurred first in these places. The low-energy properties near the hub made particles gather there, which was also the most serious cause of hub wear.

scholarly journals Study on Deformation Law of Deep Foundation Pit with the Top-Down Method and Its Influence on Adjacent Subway Tunnel

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Yue Gui ◽  
Zhenxing Zhao ◽  
Xiaqiang Qin ◽  
Jianfei Wang
Keyword(s):  
Axial Force ◽  
Ground Deformation ◽  
Diaphragm Wall ◽  
Subway Tunnel ◽  
Top Down ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Maximum Settlement ◽  
The Impact ◽  
The Relationship

Based on a long-term comprehensive instrumentation program, the performance of an excavation pit constructed by the top-down method in downtown Kunming was extensively examined. The measured excavation responses included the deflections of diaphragm wall, vertical column movement, slab axial force, building settlement caused by ground deformation, and the influence of pit excavation on the adjacent subway tunnel. This paper analyses the monitoring data of the existing construction stage. Based on the analyses on the data of field and numerical simulation, the following major findings were obtained: (1) the relationship between the measured maximum wall deflection, δ h m , and excavation depth, H , in this study is δ h m = 0.06 % H ∼ 0.27 % H , which is quite different compared with the relationship of soft-soil pit δ h m = 0.02 % H ∼ 1.2 % H , but closer to the normalized curve of rock-socketed pile δ h m = 0.01 % H ∼ 0.45 % H and rock-socketed diaphragm wall δ h m = 0.031 % H ∼ 0.129 % H . (2) The relationship between the maximum settlement of column ( δ p ) and excavation depth ( H ) is δ p = − 0.09 % ∼ 0.04 % H . The maximum distortion between the diaphragm wall and the column is less than 1/500 of the limit range proposed by Bjerrum. (3) The impact range caused by excavation is about 3.8 times the maximum excavation depth. The ground settlement around the foundation pit is groove type, and the maximum settlement point is located at 2.7 times the maximum excavation depth. (4) The excavation of the foundation pit leads to the maximum vertical settlement of 2 mm and maximum horizontal displacement of 5.2 mm in the subway tunnel; the maximum change of axial force and bending moment are 8.8 kN (the vertical direction) and 6.4 kN·m/m (the horizontal direction), respectively.

scholarly journals Speaking and Writing Interconnections: A Systematic Review

2021 ◽  
Vol 2 (2) ◽  
pp. 19-33
Author(s):  
Fouad Akki ◽  
Mohammed Larouz
Keyword(s):  
Systematic Review ◽  
Foreign Language ◽  
Empirical Research ◽  
Experimental Research ◽  
The Other ◽  
Current Review ◽  
The Impact ◽  
The Relationship

Drawing on previous studies on the relationship between speaking and writing modalities, this paper provides a critical synthesis of theoretical and empirical research on the interconnections between the two versions. Along with this, this systematic review shows that research on the issue at hand has been classified under three main categories: a) speaking effect on writing; b) writing effect on speaking, and c) correlation between speaking and writing. While experimental research has emphasized the impact of speaking and writing on each other, correlational endeavors have been much concerned with the symmetrical, reciprocal, and predictive connections between these two interrelated domains. Overall, the current review suggests that learning a second or foreign language could be enhanced by complementing speaking tasks by writing ones and vice versa. In this case, speaking could be taught along with writing to allow students to transfer their skillfulness from one to the other.

scholarly journals The Tip Clearance Cavitation Mechanism of a High-Speed Centrifugal Pump with a Splitter-Bladed Inducer

Processes ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 1576
Author(s):  
Xiaomei Guo ◽  
Shidong Yang ◽  
Xiaojun Li ◽  
Liang Shi ◽  
Ertian Hua ◽  
...  
Keyword(s):  
Centrifugal Pump ◽  
High Speed ◽  
High Performance ◽  
Static Pressure ◽  
Tip Clearance ◽  
Small Range ◽  
Suction Surface ◽  
Static Pressure Distribution ◽  
The Impact ◽  
External Characteristics

For a high-speed centrifugal pump, cavitation occurs easily. To equip a high-performance splitter-bladed inducer upstream of the pump is an effective method to suppress cavitation. In this paper, an external characteristics experiment of the high-speed centrifugal pump with a splitter-bladed inducer is carried out, and the corresponding numerical calculations are completed. The research shows that the results of the numerical calculation are credible. Numerical cavitation calculations under eight different tip clearance conditions are carried out. First, it is found that the tip clearance (TC) has a certain impact on the head of the centrifugal pump. When TC is in a small range, the clearance leakage is small, and the impact on the head of the pump is not so obvious, which can give the pump a higher performance. Second, it is found that TC has a certain influence on the static pressure distribution in the cascade passage of the splitter-bladed inducer. When TC is in a certain range, the increasement in TC will aggravate the cavitation at the suction surface of the long blades near the inlet. When it exceeds the certain range, it will cause cavitation at the outlet of the inducer. At last, it is found that the cavitation’s severity and position of the inducer are closely related to TC. TC affects the magnitude and position of vorticity in the inducer’s passage. In this paper the flow mechanism of TC is revealed, and its research results can provide theoretical basis and technical support for the design of the tip clearance of the inducers.

scholarly journals Optimization Design of Actuator Parameters with Stepless Capacity Control System Considering the Effect of Backflow Clearance

2020 ◽  
Vol 10 (8) ◽  
pp. 2703
Author(s):  
Jinjie Zhang ◽  
Chao Zhou ◽  
Zhinong Jiang ◽  
Yao Wang ◽  
Xu Sun
Keyword(s):  
Mathematical Model ◽  
Control System ◽  
Good Effect ◽  
Reciprocating Compressor ◽  
Spring Stiffness ◽  
Objective Functions ◽  
Capacity Control ◽  
Hydraulic Force ◽  
The Impact ◽  
The Relationship

The actuator is the key to the stepless capacity control system of a reciprocating compressor. The coupling effect between the actuator and the reciprocating compressor was not considered in the traditional design, and the large design margin led to low system reliability, high cost and low safety. In this paper, a reciprocating compressor and actuator were taken as research objects. The backflow clearance of the suction valve was simulated by CFD (computational fluid dynamics), The relationship between backflow clearance and resultant gas force of the valve plate was discussed. By building a mathematical model of actuators considering backflow clearance and impact rebound, the relationship between the parameters of actuators was studied. Based on the mathematical model and CFD analysis, the hydraulic force and spring stiffness were taken as the design variables, the impact velocity of ejection or withdrawal and the backflow clearance were taken as objective functions, and the actuator parameters were optimized with NSGA-II (Non-dominated Sorting Genetic Algorithm – II). The optimization results show that when the backflow clearance is 0.0065 mm, the hydraulic force is 94.25 N, and the spring stiffness is 11,575.84 N/m, the objective functions are optimized, the parameters are significantly improved, and a good effect is achieved on the experimental table of a 2D reciprocating compressor.

Whose Support Matters? Support of Friends (but Not Family) May Predict Affect and Wellbeing of Adults Faced With Negative Life Events

2017 ◽  
Vol 8 ◽  
Author(s):  
Scott P. Secor ◽  
Alicia Limke-McLean ◽  
Ronald W. Wright
Keyword(s):  
Social Support ◽  
Family Support ◽  
Psychological Health ◽  
Social Contact ◽  
Health And Wellbeing ◽  
The Face ◽  
Life Circumstances ◽  
The Impact ◽  
The Relationship ◽  
External Characteristics

Research on resilience has shown that resilient individuals possess a variety of internal characteristics (e.g., hardiness and reflectiveness) and a mixture of external characteristics (e.g., social contact and relationship recruiting) that interact to promote resilience. This research examined the relationship between social support of friends, social support of family, and resiliency to further understand the impact of social contact on psychological health and wellbeing. Study 1 showed that in the face of self-reported difficult life circumstances, friend support (but not family support) predicts most aspects of psychological wellbeing. Similarly, Study 2 found that previous reports of friend (but not family) support predicted positive affect for participants in a simulated achievement rejection experimental condition. Taken together, these studies suggest that among adults, perceived social support from friends may be more impactful than social support from family.

scholarly journals Contribution and Mechanism of Different Levels of Educational Human Capital to the Identification of Regional Green Economic Growth

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Jiapeng Guo
Keyword(s):  
Economic Growth ◽  
Human Capital ◽  
Image Recognition ◽  
Recognition System ◽  
Spatial Effect ◽  
Utilization Efficiency ◽  
Good Effect ◽  
Research Technology ◽  
The Impact ◽  
The Relationship

With the rapid development of economy and society and the continuous optimization of industrial structure, the demand for high skilled talents is increasing. Education plays an irreplaceable role in China’s economic growth. Therefore, it is of great significance to study the impact of talent supply of vocational education on economic growth from the perspective of human capital and comprehensively consider the spatial interaction of economic growth. Taking intelligent image recognition technology as the main research technology, this paper discusses the contribution of educational human capital to regional green economic growth. This paper expounds the content of intelligent image recognition technology, constructs an image recognition system based on neural network, and studies the relationship between human resource utilization efficiency and regional economy under intelligent image recognition technology based on the empirical analysis of intelligent image recognition technology. Finally, it makes an empirical study on the spatial effect in the image recognition system and expounds the relationship between feature space and economic growth. It verifies the relationship between educational human capital and green economic growth. The results show that the intelligent image recognition technology has a good effect in the research of spatial effect.

Accent Policy and Accent Modification Enterprises as Potential Indicators of Intercultural Power Relations: A Call for an Updated Research Agenda

2013 ◽  
Vol 3 (1) ◽  
pp. 22-33 ◽  
Author(s):  
Brynne D. Ovalle ◽  
Rahul Chakraborty
Keyword(s):  
International Relations ◽  
Identity Construction ◽  
Social Theory ◽  
Power Relations ◽  
Linguistic Diversity ◽  
Cultural Organization ◽  
Using Data ◽  
The Individual ◽  
The Impact ◽  
The Relationship

This article has two purposes: (a) to examine the relationship between intercultural power relations and the widespread practice of accent discrimination and (b) to underscore the ramifications of accent discrimination both for the individual and for global society as a whole. First, authors review social theory regarding language and group identity construction, and then go on to integrate more current studies linking accent bias to sociocultural variables. Authors discuss three examples of intercultural accent discrimination in order to illustrate how this link manifests itself in the broader context of international relations (i.e., how accent discrimination is generated in situations of unequal power) and, using a review of current research, assess the consequences of accent discrimination for the individual. Finally, the article highlights the impact that linguistic discrimination is having on linguistic diversity globally, partially using data from the United Nations Educational, Scientific and Cultural Organization (UNESCO) and partially by offering a potential context for interpreting the emergence of practices that seek to reduce or modify speaker accents.

Business: Making Cents of Coding Systems: Billing for Professional Services

2010 ◽  
Vol 20 (1) ◽  
pp. 3-8
Author(s):  
Dee Adams Nikjeh
Keyword(s):  
Professional Services ◽  
Speech Language Pathology ◽  
Coding Systems ◽  
Language Pathology ◽  
Program Funding ◽  
Fee Schedule ◽  
Procedure Codes ◽  
Relationship Of ◽  
The Impact ◽  
The Relationship

Abstract Administrators and supervisors face daily challenges over issues such as program funding, service fees, correct coding procedures, and the ever-changing healthcare regulations. Receiving equitable reimbursement for speech-language pathology and audiology services necessitates an understanding of federal coding and reimbursement systems. This tutorial provides information pertaining to two major healthcare coding systems and explains the relationship of these systems to clinical documentation, the Medicare Physician Fee Schedule and equitable reimbursement. An explanation of coding edits and coding modifiers is provided for use in those occasional atypical situations when the standard use of procedural coding may not be appropriate. Also included in this tutorial is a brief discussion of the impact that the Medicare Improvements for Patients and Providers Act of 2008 (HR 6331 Medicare Improvements for Patients and Providers Act [MIPPA], 2008) has had on the valuation of speech-language pathology procedure codes.

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