Model of Flow in the Side Chambers of an Industrial Centrifugal Pump for Delivering Viscous Oil

2013 ◽  
Vol 135 (5) ◽  
Author(s):  
Wenguang Li
Keyword(s):  
Centrifugal Pump ◽  
Flow Model ◽  
Rotating Disk ◽  
Mechanical Efficiency ◽  
High Viscosity ◽  
Experimental Results ◽  
Computational Method ◽  
Fluid Viscosity ◽  
Liquid Viscosity ◽  
Viscous Oil

A series of experiments has been conducted to identify the effects of both fluid viscosity and wear-rings gap on the performance of a low specific speed industrial centrifugal pump of type 65Y60 for transporting viscous oils by the author group. Unfortunately, the experimental results remained unexplained on a fluid dynamics base. To remedy this problem, a highly viscous oil flow model and computational method in the side chambers in that pump were proposed based on the existing theoretical and experimental results. The flow coupling between the chambers and the gaps of the wear-rings and/or the balance holes was realized. The model was validated by making use of the existing experiment data in the chamber between a rotating disk and the walls of a stationary cylindrical container. Then the flow model was applied into the two side chambers in that pump when the wear-rings clearances and liquid viscosity were changed. The results demonstrated that the flow model is sensitive to wear-rings gap, liquid viscosity, the roughness of the wet walls of the chambers, and leakage flow rate. For this pump, an enlarged clearance can improve the mechanical efficiency, but the increment in the efficiency is unable to compensate for the considerable drop in the volumetric efficiency, causing the gross efficiency not be improved, especially at a high viscosity.

Unsteady flow in a viscous oil transporting centrifugal pump

2011 ◽  
Vol 1 (4) ◽  
Author(s):  
Wen-Guang Li
Keyword(s):  
Unsteady Flow ◽  
Centrifugal Pump ◽  
Acoustic Resonance ◽  
High Viscosity ◽  
Broadband Noise ◽  
Centrifugal Pumps ◽  
Viscous Oil ◽  
Flow Feature ◽  
Flow Variables ◽  
Ldv Measurement

AbstractAcoustic resonances are frequently fatal problems in centrifugal pump operations. Low pressure pulsation of fluid in the blade pass frequency is helpful to prevent from such problems. In addition, for a high quality centrifugal pump, a lower broadband noise level is also on demand. The acoustic resonance and broadband noise are associated with unsteadiness of flow in the pump. Even there exist extensive analyses of unsteady flow in centrifugal pumps by means of CFD so far, the effect of high viscosity of fluid pumped on the unsteadiness of flow feature remains unclear. Thus, the unsteady flow in an experimental centrifugal pump was exploited numerically when it transported the liquids with different viscosities. The velocity profiles at the impeller discharge were validated with the results of LDV measurement for water. The viscosity effect on the fluctuation of flow in the volute was clarified quantitatively. It was shown the increasing viscosity of fluid makes the fluctuation in flow variables less substantial and results into a less noticed tendency of separation of flow from the blade pressure side.

scholarly journals Numerical Study on Deformation and Interior Flow of a Droplet Suspended in Viscous Liquid under Steady Electric Fields

2014 ◽  
Vol 6 ◽  
pp. 532797 ◽  
Author(s):  
Zhentao Wang ◽  
Qingming Dong ◽  
Yonghui Zhang ◽  
Junfeng Wang ◽  
Jianlong Wen
Keyword(s):  
Electric Fields ◽  
Numerical Study ◽  
Internal Flow ◽  
High Viscosity ◽  
Numerical Results ◽  
Experimental Results ◽  
Fluid Viscosity ◽  
Single Droplet ◽  
Deformation Velocity ◽  
Interior Flow

A model based on the volume of fluid (VOF) method and leaky dielectric theory is established to predict the deformation and internal flow of the droplet suspended in another vicious fluid under the influence of the electric field. Through coupling with hydrodynamics and electrostatics, the rate of deformation and internal flow of the single droplet are simulated and obtained under the different operating parameters. The calculated results show that the direction of deformation and internal flow depends on the physical properties of fluids. The numerical results are compared with Taylor's theory and experimental results by Torza et al. When the rate of deformation is small, the numerical results are consistent with theory and experimental results, and when the rate is large the numerical results are consistent with experimental results but are different from Taylor's theory. In addition, fluid viscosity hardly affects the deformation rate and mainly dominates the deformation velocity. For high viscosity droplet spends more time to attain the steady state. The conductivity ratio and permittivity ratio of two different liquids affect the direction of deformation. When fluid electric properties change, the charge distribution at the interface is various, which leads to the droplet different deformation shapes.

scholarly journals Analytical viscous flow model and test validation of a swirl injector for rocket engine application

2019 ◽  
Author(s):  
G. Fiore ◽  
C. Bach ◽  
J. Sieder ◽  
M. Tajmar
Keyword(s):  
Flow Model ◽  
Rocket Engine ◽  
High Viscosity ◽  
Liquid Oxygen ◽  
Fluid Viscosity ◽  
Prediction Errors ◽  
Viscous Effects ◽  
Swirl Injector ◽  
Close Form

The generally adopted flow model inside a swirl injector, widely used injection concept for propulsive applications, relies upon the hypothesis of ideal flow neglecting the fluid viscosity effects. This model showed significant prediction errors with relatively high viscosity propellants, often leading to the need of an experimental characterization of the injection elements. In this paper, an analytical approach is presented, which includes the effects of viscous diffusion on the injector performance leading to a close form flow solution. The built model is thus experimentally validated testing a liquid oxygen (LOx) and an ethanol injector: the good agreement between the model and the experimental results leads to the construction of the injectors operational maps describing the injector behavior even in the presence of viscous effects.

scholarly journals Slug Translational Velocity for Highly Viscous Oil and Gas Flows in Horizontal Pipes

Fluids ◽  
2019 ◽  
Vol 4 (3) ◽  
pp. 170 ◽  
Author(s):  
Baba ◽  
Archibong-Eso ◽  
Aliyu ◽  
Ribeiro ◽  
Lao ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Prediction Models ◽  
High Viscosity ◽  
Internal Diameter ◽  
Viscosity Data ◽  
Fluid Viscosity ◽  
Liquid Viscosity ◽  
Translational Velocity ◽  
Two Phase ◽  
Low Viscosity

Slug translational velocity, described as the velocity of slug units, is the summation of the maximum mixture velocity in the slug body and the drift velocity. Existing prediction models in literature were developed based on observation from low viscosity liquids, neglecting the effects of fluid properties (i.e., viscosity). However, slug translational velocity is expected to be affected by the fluid viscosity. Here, we investigate the influence of high liquid viscosity on slug translational velocity in a horizontal pipeline of 76.2-mm internal diameter. Air and mineral oil with viscosities within the range of 1.0–5.5 Pa·s were used in this investigation. Measurement was by means of a pair of gamma densitometer with fast sampling frequencies (up to 250 Hz). The results obtained show that slug translational velocity increases with increase in liquid viscosity. Existing slug translational velocity prediction models in literature were assessed based on the present high viscosity data for which statistical analysis revealed discrepancies. In view of this, a new empirical correlation for the calculation of slug translational velocity in highly viscous two-phase flow is proposed. A comparison study and validation of the new correlation showed an improved prediction performance.

scholarly journals High Viscosity Land Based Oil Flow Model

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Daniel Mendelsohn ◽  
Eric Comerma ◽  
Matt Bernardo ◽  
Jeremy Fontenault ◽  
Sitara Baboolal
Keyword(s):  
Shear Stress ◽  
Pressure Gradient ◽  
Flow Model ◽  
High Viscosity ◽  
Surface Boundary ◽  
Viscous Oil ◽  
Oil Flow ◽  
Downslope Flow ◽  
High Viscosity Oil ◽  
Highly Viscous Oil

ABSTRACT Highly viscous oil does not behave the same as other regular liquid hydrocarbon mixtures. To evaluate the effects of a potential land-based blowout on the surrounding environment, RPS implemented a multi-step approach to simulate the trajectory and fate of high viscosity oil downslope flow. If spilled on land, initially warm oil cools and tends to gel, implying a non-Newtonian flow. To predict the behavior of high viscosity oil as it flows downslope, spreads and cools, RPS developed a new unique land-based spill model. The behavior of highly viscous crude oil has many similarities to volcanic lava flows, particularly the stark changes in oil viscosity and shear stress as the fluid cools. This study describes a “lava” flow numerical model developed to simulate the response of high viscosity oils. The viscous flow model is based on the lava model of Griffiths (2000) which simulates the unconfined motion of a Bingham fluid down a plane of constant slope. The model allows all physical and chemical parameters to vary continuously downslope. The lateral flow is assumed to cease when the cross-slope pressure gradient is balanced by the basal-yield stress also giving the height of the flow (H) on the center line of the flow as a function of shear stress. For oil flow motion the downslope pressure gradient must be greater than the oil shear stress and hence there is a critical height, based on the local oil shear stress and slope, below which there will be no downslope motion. An atmospheric heat transfer equation was applied to the oil surface as the surface boundary condition. The model was applied to a hypothetical on land release of highly viscous oil in a one-dimensional, downslope form, where the ground slope was assumed constant along the flow path. As the oil progresses downslope, its temperature was updated each time step in each cell and used to calculate new oil properties for density, specific heat, viscosity, and shear stress. The model results provide information about the rate and total distance travelled and time for the downslope flow to stop.

Fluid-property effects on flow-generated waves on a compliant surface

1983 ◽  
Vol 133 ◽  
pp. 161-177 ◽  
Author(s):  
R. J. Hansen ◽  
D. L. Hunston
Keyword(s):  
Molecular Weight ◽  
Experimental Study ◽  
Flow Velocity ◽  
Entire Range ◽  
Wave Structure ◽  
Rotating Disk ◽  
Fluid Viscosity ◽  
Liquid Viscosity ◽  
Compliant Surface ◽  
Onset Velocity

An experimental study of the influence of liquid viscosity and viscoelasticity on flow-generated waves on a compliant surface has been conducted in a rotating-disk geometry. Over the entire range of liquid properties studied, each test gave a well-defined critical onset flow velocity above which waves were present and below which no waves were observed. This onset velocity increased with increasing fluid viscosity, and for sufficiently high viscosities the onset occurred when the flow on the disk was laminar rather than turbulent. The effects of liquid viscoelasticity were examined in the turbulent flow using dilute solutions of high-molecular-weight polymers. This type of viscoelasticity had little influence on the onset flow velocity in these circumstances, but did make the wave structure on the surface more regular in appearance than when the liquid was Newtonian. In all cases the wave structure produced a dramatic increase in drag similar to that expected for a rough surface. For the viscoelastic fluid, however, the increase in drag was much less than for a viscous fluid of the same viscosity.

A Computational Method for the Identification of Endolysins and Autolysins

2020 ◽  
Vol 27 (4) ◽  
pp. 329-336 ◽  
Author(s):  
Lei Xu ◽  
Guangmin Liang ◽  
Baowen Chen ◽  
Xu Tan ◽  
Huaikun Xiang ◽  
...  
Keyword(s):  
Support Vector Machine ◽  
Cell Wall ◽  
Experimental Results ◽  
Computational Method ◽  
Lytic Enzyme ◽  
Support Vector ◽  
Lytic Enzymes ◽  
Data Set ◽  
Optimal Feature ◽  
Better Than

Background: Cell lytic enzyme is a kind of highly evolved protein, which can destroy the cell structure and kill the bacteria. Compared with antibiotics, cell lytic enzyme will not cause serious problem of drug resistance of pathogenic bacteria. Thus, the study of cell wall lytic enzymes aims at finding an efficient way for curing bacteria infectious. Compared with using antibiotics, the problem of drug resistance becomes more serious. Therefore, it is a good choice for curing bacterial infections by using cell lytic enzymes. Cell lytic enzyme includes endolysin and autolysin and the difference between them is the purpose of the break of cell wall. The identification of the type of cell lytic enzymes is meaningful for the study of cell wall enzymes. Objective: In this article, our motivation is to predict the type of cell lytic enzyme. Cell lytic enzyme is helpful for killing bacteria, so it is meaningful for study the type of cell lytic enzyme. However, it is time consuming to detect the type of cell lytic enzyme by experimental methods. Thus, an efficient computational method for the type of cell lytic enzyme prediction is proposed in our work. Method: We propose a computational method for the prediction of endolysin and autolysin. First, a data set containing 27 endolysins and 41 autolysins is built. Then the protein is represented by tripeptides composition. The features are selected with larger confidence degree. At last, the classifier is trained by the labeled vectors based on support vector machine. The learned classifier is used to predict the type of cell lytic enzyme. Results: Following the proposed method, the experimental results show that the overall accuracy can attain 97.06%, when 44 features are selected. Compared with Ding's method, our method improves the overall accuracy by nearly 4.5% ((97.06-92.9)/92.9%). The performance of our proposed method is stable, when the selected feature number is from 40 to 70. The overall accuracy of tripeptides optimal feature set is 94.12%, and the overall accuracy of Chou's amphiphilic PseAAC method is 76.2%. The experimental results also demonstrate that the overall accuracy is improved by nearly 18% when using the tripeptides optimal feature set. Conclusion: The paper proposed an efficient method for identifying endolysin and autolysin. In this paper, support vector machine is used to predict the type of cell lytic enzyme. The experimental results show that the overall accuracy of the proposed method is 94.12%, which is better than some existing methods. In conclusion, the selected 44 features can improve the overall accuracy for identification of the type of cell lytic enzyme. Support vector machine performs better than other classifiers when using the selected feature set on the benchmark data set.

Numerical simulation and experimental performance research of cylindrical vane pump

2021 ◽  
pp. 095440622110200
Author(s):  
Yiqi Cheng ◽  
Xinhua Wang ◽  
Waheed Ur Rehman ◽  
Tao Sun ◽  
Hasan Shahzad ◽  
...  
Keyword(s):  
Numerical Analysis ◽  
Rotational Velocity ◽  
Geometric Theory ◽  
Mechanical Efficiency ◽  
Operating Conditions ◽  
Experimental Results ◽  
Field Analysis ◽  
Total Efficiency ◽  
Three Dimensional Model ◽  
Vane Pump

This study presents a novel cylindrical vane pump based on the traditional working principle. The efficiency of the cylindrical vane pump was verified by experimental validation and numerical analysis. Numerical analysis, such as kinematics analysis, was performed in Pro/Mechanism and unsteady flow-field analysis was performed using ANSYS FLUENT. The stator surface equations were derived using the geometric theory of the applied spatial triangulation function. A three-dimensional model of the cylindrical vane pump was established with the help of MATLAB and Pro/E. The kinematic analysis helped in developing kinematic equations for cylindrical vane pumps and proved the effectiveness of the structural design. The maximum inaccuracy error of the computational fluid dynamics (CFD) model was 5.7% compared with the experimental results, and the CFD results show that the structure of the pump was reasonable. An experimental test bench was developed, and the results were in excellent agreement with the numerical results of CFD. The experimental results show that the cylindrical vane pump satisfied the three-element design of a positive-displacement pump and the trend of changes in efficiency was the same for all types of efficiency under different operating conditions. Furthermore, the volumetric efficiency presented a nonlinear positive correlation with increased rotational velocity, the mechanical efficiency showed a nonlinear negative correlation, and the total efficiency first increased and then decreased. When the rotational velocity was 1.33[Formula: see text] and the discharge pressure was 0.68[Formula: see text], the total efficiency reached its maximum value.

scholarly journals Using the Relevance Vector Machine Model Combined with Local Phase Quantization to Predict Protein-Protein Interactions from Protein Sequences

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Ji-Yong An ◽  
Fan-Rong Meng ◽  
Zhu-Hong You ◽  
Yu-Hong Fang ◽  
Yu-Jun Zhao ◽  
...  
Keyword(s):  
Protein Sequences ◽  
Relevance Vector Machine ◽  
Experimental Results ◽  
Computational Method ◽  
Support Vector ◽  
Svm Classifier ◽  
Local Phase ◽  
Local Phase Quantization ◽  
Phase Quantization ◽  
Better Than

We propose a novel computational method known as RVM-LPQ that combines the Relevance Vector Machine (RVM) model and Local Phase Quantization (LPQ) to predict PPIs from protein sequences. The main improvements are the results of representing protein sequences using the LPQ feature representation on a Position Specific Scoring Matrix (PSSM), reducing the influence of noise using a Principal Component Analysis (PCA), and using a Relevance Vector Machine (RVM) based classifier. We perform 5-fold cross-validation experiments onYeastandHumandatasets, and we achieve very high accuracies of 92.65% and 97.62%, respectively, which is significantly better than previous works. To further evaluate the proposed method, we compare it with the state-of-the-art support vector machine (SVM) classifier on theYeastdataset. The experimental results demonstrate that our RVM-LPQ method is obviously better than the SVM-based method. The promising experimental results show the efficiency and simplicity of the proposed method, which can be an automatic decision support tool for future proteomics research.

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