Simulation Study for the Effects of Clearance Volume on Full Metal Single Screw Pump Performance

2013 ◽  
Vol 561 ◽  
pp. 368-373
Author(s):  
Jun Fei Wu ◽  
Fan Guo Meng ◽  
Xu Ping Zhang ◽  
Ying Yu
Keyword(s):  
3D Model ◽  
Pressure Change ◽  
Screw Pump ◽  
Pump Performance ◽  
Outlet Pressure ◽  
Single Screw ◽  
Fluent Software ◽  
Volume Method ◽  
Pressure Changes ◽  
Stators And Rotors

The stators and rotors of full metal screw pump take way of clearance fit, so the clearance value will directly affect the pump lifting performance and efficiency. Firstly using the finite volume method to establish a full-metal single screw pump 3D model, secondly using FLUENT software to calculate outlet pressure changes with different series of clearance value between the stator and the rotor of the pump in condition of the same inlet pressure .lastly Drawing outlet pressure change curves to evaluate the concrete effect of clearance volume on the performance of the pump. The results indicate that the pump outlet pressure increased first and then decreased with increasing clearance value and that pump has good lifting oil capacity with clearance value which is less than 0.5mm.

Simulation Study for the Effect of Oil Viscosityon Performance of Full Metal Single Screw Pump

2013 ◽  
Vol 561 ◽  
pp. 362-367
Author(s):  
Jun Fei Wu ◽  
Xiao Wei ◽  
Xue Zheng Yang ◽  
Ying Yu
Keyword(s):  
Pressure Change ◽  
Oil Viscosity ◽  
Screw Pump ◽  
Outlet Pressure ◽  
Single Screw ◽  
Pump Output ◽  
Fluent Software ◽  
Volume Method ◽  
Pressure Changes ◽  
Filling Coefficient

Abstract: The oil viscosity affects the pump filling coefficient, so it is the important parameter affecting lifting performance of metal screw pump. Firstly using the finite volume method to establish a full-metal single screw pump 3D model, secondly using FLUENT software to calculate outlet pressure changes with different series of oil viscosity in condition of the same inlet pressure.Lastly Drawing outlet pressure change curves to evaluate the concrete effect of oil viscosity on the performance of the pump . The results indicate that the oil viscosity affects liquid filling coefficient of pump. As the viscosity increases, the outlet pressure of the pump increases, the leakage of the pump output decreases, thereby lifting capacity and volumetric efficiency of the pump improve.

Simulation Study for the Effects of Rotational Speed on Performance of Full Metal Single Screw Pump

2013 ◽  
Vol 561 ◽  
pp. 384-389
Author(s):  
Jun Fei Wu ◽  
Jun Bin Lan ◽  
Fan Guo Meng ◽  
Xu Ping Zhang ◽  
Ying Yu
Keyword(s):  
Rotational Speed ◽  
Double Helix ◽  
Pressure Change ◽  
Basic Theory ◽  
Normal Operation ◽  
Screw Pump ◽  
Pump Performance ◽  
Outlet Pressure ◽  
Single Screw ◽  
Lifting Capacity

Rotational speed is one of the important parameters that impact lifting capacity of full-metal single screw pump .Firstly using the finite volume method to establish a full-metal single screw pump 3D model, secondly using FLUENT software to calculate outlet pressure changes with different series of rotational speed value of the pump in condition of the same inlet pressure .Lastly drawing outlet pressure change curves to evaluate the concrete effect of rotational speed on the performance of the pump. The results indicate that the lifting capacity of the pump and pressure bearing capacity of single stage increase with the rotational speed increasing. The centrifugal performance of the full metal single screw pump is more obvious. So it needs to give full consideration to the effect of rotational speed on characteristics of screw pump in the process of screw pump designing and using, especially the selection of pump series and rotational speed .Increasing the rotational speed of the screw pump can not only reduce the pump series and the structural size, but also can reduce the load torque, improve the reliability of drive system.Now,most of traditional rubber stator is cast one layer rubber that is of double helix surface in the metal enclosure, which can be used together with the metal rotor whose outer surface is plated by hard chrome, while working, the stator can be easily damaged because of the swelling, temperature expansion, and easy to aging of the rubber. As the stator is connected with the tubing, while the stator is damaged and we need to replace a new one, we should disassemble both the poles and string, and it leads to a high cost and the stator can not be used any more, which is apparently a great waste of resource. Besides, that the rubber in the inner surface is hard to clear is also one reason leading to the useless of the stator[1]. Full-metal single screw pump can avoid these shortcomings for its stator and rotor are made of metal materials and they take way of clearance fit. This can ensure the screw pump develops the higher working efficiency in normal operation. However the full-metal single screw pump developed quite late, its theoretical study and basic theory is less and not mature[2]. Rotational speed is the main parameter in the designing and using of full metal screw pump ,so in order to help improve the screw pump performance and for further study of the basic theory of metal screw pump, this paper will focus on the study of effect of rotational speed on the pump performance .

Research on the Impacts of Screw Speed on All-Metal Screw Pump

2014 ◽  
Vol 703 ◽  
pp. 425-429
Author(s):  
Jun Fei Wu ◽  
Zhi Li ◽  
Fan Guo Meng ◽  
Ben Liang Yu
Keyword(s):  
Geometric Model ◽  
Constraint Condition ◽  
3D Flow ◽  
Screw Speed ◽  
Ansys Fluent ◽  
Screw Pump ◽  
Single Screw ◽  
Dynamic Mesh Technique ◽  
Fluent Software ◽  
Mesh Technique

Compared with traditional screw pump,all-metal screw pump have more advantages in the oil extraction. In this paper, all-metal single screw pump's geometric model was made by PROE software; then the dynamic mesh technique was applied to mesh the model and constraint condition was applied in the ANSYS-FLUENT software. 3D flow field was numerical analyzed In that software, the impacts of screw speed on volume flow and volumetric efficiency were concluded, the conclusion can offer some valuable guidances to the all-metal single screw pump's design.

Numberical Simulation of Labyrinth Screw Pump with Separated Structure by Fluent

2013 ◽  
Vol 455 ◽  
pp. 242-247
Author(s):  
Jiao Jiao Li ◽  
You Cheng Zhang
Keyword(s):  
Renormalization Group ◽  
Single Phase ◽  
3D Model ◽  
Phase Flow ◽  
Single Phase Flow ◽  
Screw Pump ◽  
Pump Performance ◽  
Simplec Algorithm ◽  
Multiple Reference ◽  
Length Limitation

3D model and grid was conducted in Gambit,while single-phase flow field in the pump was simulated in CFD code-Fluent,by means of multiple reference frame (MRF) method, Renormalization group k-ε two-equation turbulence model (RNG k-εmodel) and Semi-Implicit Method for Pressure-Linked Equations (SIMPLEC) algorithm. Aim at problems generated by pump body such as body length limitation on pressure increasing, three new structure of labyrinth screw pumps,rotor separated LSP,stator separated LSP and rotor stator all separated LSP, were put forward in this paper.The analytical results got by contrasted pump hydraulic performance of different structure models indicated that pressure increasing magnitude and pressure increasing rate of the three separated pumps is larger compared to the unseparated pumps,and the conclusion was achieved that pump performance can be optimized through separating rotor or stator into sections by making ring slots on screw body.

Analyzing Rotor Profile’s Effects to Performance of Roots Vacuum Pump Applied the CFD Method

2019 ◽  
Vol 889 ◽  
pp. 518-525
Author(s):  
Thanh Tung Nguyen ◽  
Bui Ngoc Tuyen ◽  
Van The Tran
Keyword(s):  
Geometric Analysis ◽  
Vacuum Pump ◽  
Pump Performance ◽  
Outlet Pressure ◽  
Rotor Profile ◽  
Fluent Software ◽  
Simulation Results ◽  
Cfd Method ◽  
Rotor Profiles ◽  
Lobe Pump

The paper is mainly focused on analysis characteristics of lobe pump with three different tooth profiles: Circular, Epi-cycloidal and Circular–Involute–Circular (CIC) rotor profiles. Based on the geometric analysis and mathematical model, the CIC rotor profile combined Circular–Involute–Circular is generated. In this paper, the CFD techniques are used to estimate the effects of tooth profile and lobe number to the pump performance. The simulation results obtained from FLUENT software illustrated that the rotor profile effects remarkably to the pump performance. The outlet pressure of CIC rotor profile is higher than that of the circular and epi-cycloidal rotor profiles. The numerical outcomes also showed that higher rotor’s speed is resulted in higher outlet pressure. Besides, the lobe number of rotor has effect slightly to the pump performance.

Heart Rate Signal Decomposition

2000 ◽  
Vol 39 (02) ◽  
pp. 200-203
Author(s):  
H. Mizuta ◽  
K. Yana
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Pressure Change ◽  
Normal Subjects ◽  
Signal Decomposition ◽  
Large Individual ◽  
Heart Rate Fluctuations ◽  
Type Pattern ◽  
Signal Cancellation ◽  
Pressure Changes

Abstract:This paper proposes a method for decomposing heart rate fluctuations into background, respiratory and blood pressure oriented fluctuations. A signal cancellation scheme using the adaptive RLS algorithm has been introduced for canceling respiration and blood pressure oriented changes in the heart rate fluctuations. The computer simulation confirmed the validity of the proposed method. Then, heart rate fluctuations, instantaneous lung volume and blood pressure changes are simultaneously recorded from eight normal subjects aged 20-24 years. It was shown that after signal decomposition, the power spectrum of the heart rate showed a consistent monotonic 1/fa type pattern. The proposed method enables a clear interpretation of heart rate spectrum removing uncertain large individual variations due to the respiration and blood pressure change.

Study of Toynbee Phenomenon by Combined Intranasopharyngeal and Tympanometric Measurements

1988 ◽  
Vol 97 (2) ◽  
pp. 199-206 ◽  
Author(s):  
Yehuda Finkelstein ◽  
Yuval Zohar ◽  
Yoav P. Talmi ◽  
Nelu Laurian
Keyword(s):  
Middle Ear ◽  
Negative Pressure ◽  
Pressure Change ◽  
Positive Pressure ◽  
New Information ◽  
Pressure Changes ◽  
Rapid Pressure

The Toynbee maneuver, swallowing when the nose is obstructed, leads in most cases to pressure changes in one or both middle ears, resulting in a sensation of fullness. Since first described, many varying and contradictory comments have been reported in the literature concerning the type and amount of pressure changes both in the nasopharynx and in the middle ear. In our study, the pressure changes were determined by catheters placed into the nasopharynx and repeated tympanometric measurements. New information concerning the rapid pressure variations in the nasopharynx and middle ear during deglutition with an obstructed nose was obtained. Typical individual nasopharyngeal pressure change patterns were recorded, ranging from a maximal positive pressure of + 450 to a negative pressure as low as −320 mm H2O.

Bifurcation analysis of two-dimensional laminar flow through sudden expansion channel

2022 ◽  
Vol 13 (1) ◽  
pp. 0-0
Keyword(s):  
Laminar Flow ◽  
Expansion Ratio ◽  
Sudden Expansion ◽  
Two Dimensional ◽  
Governing Equations ◽  
Bifurcation Phenomena ◽  
Different Types ◽  
Fluent Software ◽  
Flow Through ◽  
Volume Method

In this work, bifurcation characteristics of unsteady, viscous, Newtonian laminar flow in two-dimensional sudden expansion and sudden contraction-expansion channels have been studied for different values of expansion ratio. The governing equations have been solved using finite volume method and FLUENT software has been employed to visualize the simulation results. Three different mesh studies have been performed to calculate critical Reynolds number (Recr) for different types of bifurcation phenomena. It is found that Recr decreases with the increase in expansion ratio (ER).

Association between ibrutinib treatment and hypertension

Heart ◽  
2021 ◽  
pp. heartjnl-2021-319110
Author(s):  
Dae Hyun Lee ◽  
Fahad Hawk ◽  
Kieun Seok ◽  
Matthew Gliksman ◽  
Josephine Emole ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Systolic Blood Pressure ◽  
Repeated Measures ◽  
Treatment Initiation ◽  
Kinase Inhibitor ◽  
Pressure Change ◽  
Exact Test ◽  
N 93 ◽  
Pressure Changes ◽  
Over Time

BackgroundIbrutinib is a tyrosine kinase inhibitor most commonly associated with atrial fibrillation. However, additional cardiotoxicities have been identified, including accelerated hypertension. The incidence and risk factors of new or worsening hypertension following ibrutinib treatment are not as well known.MethodsWe conducted a retrospective study of 144 patients diagnosed with B cell malignancies treated with ibrutinib (n=93) versus conventional chemoimmunotherapy (n=51) and evaluated their effects on blood pressure at 1, 2, 3 and 6 months after treatment initiation. Descriptive statistics were used to compare baseline characteristics for each treatment group. Fisher’s exact test was used to identify covariates significantly associated with the development of hypertension. Repeated measures analyses were conducted to analyse longitudinal blood pressure changes.ResultsBoth treatments had similar prevalence of baseline hypertension at 63.4% and 66.7%, respectively. There were no differences between treatments by age, sex and baseline cardiac comorbidities. Both systolic and diastolic blood pressure significantly increased over time with ibrutinib compared with baseline, whereas conventional chemoimmunotherapy was not associated with significant changes in blood pressure. Baseline hypertensive status did not affect the degree of blood pressure change over time. A significant increase in systolic blood pressure (defined as more than 10 mm Hg) was noted for ibrutinib (36.6%) compared with conventional chemoimmunotherapy (7.9%) at 1 month after treatment initiation. Despite being hypertensive at follow-up, 61.2% of patients who were treated with ibrutinib did not receive adequate blood pressure management (increase or addition of blood pressure medications). Within the ibrutinib group, of patients who developed more than 20 mm Hg increase in systolic blood pressure, only 52.9% had hypertension management changes.ConclusionsIbrutinib is associated with the development of hypertension and worsening of blood pressure. Cardiologists and oncologists must be aware of this cardiotoxicity to allow timely management of blood pressure elevations.

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