scholarly journals Numerical and Analytical Modeling of Centrifugal Pump

2021 ◽  
pp. 215-225
Author(s):  
Viktor A. Ivanov ◽  
Nikolay V. Erkaev
Keyword(s):  
Mathematical Model ◽  
Centrifugal Pump ◽  
Analytical Modeling ◽  
Analytical Calculation ◽  
Preliminary Calculation ◽  
Ansys Fluent ◽  
Stationary Rotation

A mathematical model of non-stationary rotation modes of the rotor of a centrifugal pump is constructed. It is based on preliminary calculation in ANSYS Fluent package with subsequent analytical calculation taking into account the specified parameters

scholarly journals Numerical Simulation of Solids Conveying in Grooved Feed Sections of Single Screw Extruders

Polymers ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 256
Author(s):  
Florian Brüning ◽  
Volker Schöppner
Keyword(s):  
Numerical Simulation ◽  
Analytical Modeling ◽  
Flow Behavior ◽  
Analytical Calculation ◽  
Statistical Design ◽  
Simulation Software ◽  
Special Focus ◽  
Statistical Design Of Experiments ◽  
Complex Flow ◽  
Single Screw Extruders

For plastic processing extruders with grooved feed sections, the design of the feed section by means of analytical calculation models can be useful to reduce experimental costs. However, these models include assumptions and simplifications that can significantly decrease the prediction accuracy of the throughput due to complex flow behavior. In this paper, the accuracy of analytical modeling for calculating the throughput in a grooved barrel extruder is verified based on a statistical design of experiments. A special focus is placed on the assumptions made in the analytics of a backpressure-independent throughput, the assumption of a block flow and the differentiation of the solids conveying into different conveying cases. Simulative throughput tests with numerical simulation software using the discrete element method, as well as experimental throughput tests, serve as a benchmark. Overall, the analytical modeling already shows a very good calculation accuracy. Nevertheless, there are some outliers that lead to larger deviations in the throughput. The model predominantly overestimates the throughputs, whereby the origin of these deviations is often in the conveying angle calculation. Therefore, a regression-based correction factor for calculating the conveying angle is developed and implemented.

scholarly journals Analytical calculation of time of reaching specific values based on visibility loss during a fire

2018 ◽  
Vol 193 ◽  
pp. 03007 ◽  
Author(s):  
Sergei Kolodyazhniy ◽  
Vladimir Kozlov
Keyword(s):  
Mathematical Model ◽  
Analytical Solutions ◽  
Ventilation System ◽  
Analytical Calculation ◽  
Critical Time ◽  
Original Data ◽  
Critical Value ◽  
Time Intervals ◽  
Evacuation Time ◽  
Analytical Formulas

Using an integral mathematical model of a fire considering the assumptions typical of a starting stage of a fire, analytical dependencies were obtained for determining the time of reaching a critical value of the density of a smoke screen in a premises with a fire epicenter and adjoining premises. By means of analytical formulas for determining critical evacuation time intervals based on visibility loss, table values for different parameters that are included in the original equations were obtained. Simple engineering analytical solutions that describe the dynamics of smoke formation in premises in case of a fire when used in a certain combination are presented. The obtained dependencies allow one to identify the critical time of evacuation with no use of special PC software as well as to obtain original data without calculating an anti-smoke ventilation system.

Numerical Research of the Effect of the Outlet Diameter of Diffuser on the Performance and the Radial Force in a Single-Stage Centrifugal Pump

2014 ◽  
Author(s):  
Jiang Wei ◽  
Li Guojun ◽  
Liu Pengfei ◽  
Zhang Lisheng ◽  
Qing Hongyang
Keyword(s):  
Centrifugal Pump ◽  
Radial Force ◽  
Numerical Results ◽  
Operating Conditions ◽  
Single Stage ◽  
Navier Stokes ◽  
Computational Domain ◽  
Ansys Fluent ◽  
Vaned Diffuser ◽  
Unsteady Numerical Simulation

In this paper, a single-stage pump with diffuser vanes of different outlet diameters has been investigated both numerically and experimentally. The influence of the diffuser vane outlet diameter on pump hydraulic performance and on the radial force of the impeller is explored. Pumps equipped with three different diffusers but with impellers and volutes of the same parameters were simulated by 3D Navier-Stokes solver ANSYS-FLUENT in order to study the effect of the outlet diameter of vaned diffuser on performance of the centrifugal pump. Structured grids of high quality were applied on the whole computational domain. Experimental results were acquired by prototype experiments and were then compared with the numerical results. Both experimental and numerical results show that the performance of a pump with a diffuser of smaller outlet diameter is better than of bigger outlet diameter under all operating conditions. The radial force imposed on the impeller obtained by unsteady numerical simulation was analyzed. The results also indicated that an appropriate decrease in the outlet diameter of the diffuser vane could increase the radial force.

Research on Tool-Path Generating Methods for NC Machining of Centrifugal Pump Vanes

2010 ◽  
Vol 26-28 ◽  
pp. 982-987
Author(s):  
Xiu Ting Wei ◽  
Qiang Du ◽  
Jing Cheng Liu
Keyword(s):  
Mathematical Model ◽  
Centrifugal Pump ◽  
Iterative Algorithm ◽  
Tool Path ◽  
Tool Path Generation ◽  
Terminal Condition ◽  
Path Generation ◽  
Contact Parameter ◽  
Nc Program ◽  
The Mathematical Model

The universal NC program was inefficient for machining centrifugal pump vanes and a new tool-path generation method along section lines was proposed in this paper. After analyzing curve characteristics of centrifugal pump vanes, the mathematical model for calculating cutting step-lengths and determining the next tool contact parameter ui+1 through step estimating method was put forward. Furthermore, a new iterative algorithm was implemented, along with its terminal condition simplified. The proposed algorithm provided a new idea for developing special NC program of impellers.

Mathematical model of energy conversion mechanism in screw centrifugal pump based on load criteria of blade airfoil

2017 ◽  
Vol 34 (7) ◽  
pp. 2168-2188 ◽  
Author(s):  
Hui Quan ◽  
Baiheng Fu ◽  
Rennian Li ◽  
Guangxian Li ◽  
Zhengjie Zhang ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Energy Transfer ◽  
Energy Conversion ◽  
Centrifugal Pump ◽  
Lift Coefficient ◽  
Energy Conversion Efficiency ◽  
Solid Particles ◽  
Content Type ◽  
Wrap Angle

Purpose To analyze the work principle and capacity of energy conversion in each segment of profile lines, the energy transfer from impeller to transmission medium is separated into head coefficient and load coefficient to analyze the energy transfer process. The concepts of airfoil lift coefficient and drag coefficient are used; the third manifestation of the Euler equations is used as well. Design/methodology/approach The numerical simulation of energy conversion mechanism based on load criteria of vane airfoil has been established in screw centrifugal pump to explain its energy conversion mechanism in an impeller. Upon this basis, the velocity and pressure along the entire blade are investigated through the numerical simulation of internal solid–liquid flow in the pump. The energy conversion process under load criteria in the blade airfoil has also been obtained. Findings The research suggests that the mathematical model of energy conversion mechanism based on the load criteria of the vane airfoil is reliable in the screw centrifugal pump. The screw centrifugal blade has twice or even several times the wrap angle than the ordinary centrifugal blade. It is a large wrap angle that forms the unique flow channel which lays the foundation for solid particles to pass smoothly and for soft energy conversion. At the same time, load distribution along the profile line on the long-screw centrifugal blade is an important factor affecting the energy conversion efficiency of the impeller. Originality/value The quantitative analysis method of energy in the screw centrifugal pump can help the pump designer improve certain features of the pump and shorten the research cycle.

scholarly journals Analytical Modeling of a Ball Screw Feed Drive for Vibration Prediction of Feeding Carriage of a Spindle

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Lei Zhang ◽  
Taiyong Wang ◽  
Songling Tian ◽  
Yong Wang
Keyword(s):  
Mathematical Model ◽  
Analytical Modeling ◽  
Contact Stiffness ◽  
Ball Screw ◽  
Linear Guide ◽  
Feed Drives ◽  
Vibration Prediction ◽  
Spring System ◽  
Mass Spring ◽  
Screw Feed

An analytical modeling approach for ball screw feed drives is proposed to predict the dynamic behavior of the feeding carriage of a spindle. Mainly considering the rigidity of linear guide modules, a ball-screw-feeding spindle is modeled by a mass-spring system. The contact stiffness of rolling interfaces in linear guide modules is accurately calculated according to the Hertzian theory. Next, a mathematical model is derived using the Lagrange method. The presented model is verified by conducting modal experiments. It is found that the simulated results correspond closely with the experimental data. In order to show the applicability of the proposed mathematical model, parameter-dependent dynamics of the feeding carriage of the spindle is investigated. The work will contribute to the vibration prediction of spindles.

scholarly journals Modeling of human breath: conceptual and mathematical statements

2016 ◽  
Vol 11 (1) ◽  
pp. 64-80 ◽  
Author(s):  
П.В. Трусов ◽  
P.V. Trusov
Keyword(s):  
Mathematical Model ◽  
Flow Characteristics ◽  
Quiet Breathing ◽  
Ansys Fluent ◽  
Proposed Model ◽  
Joint Problem ◽  
Large Airways ◽  
Further Development ◽  
And Diffusion ◽  
Joint Problem Solving

The article is devoted to the main aspects of the development of a mathematical model of the human respiratory system taking into account the effects of environmental factors. The proposed model is a submodel of "meso-level" multilayered mathematical model of the evolution of functional disorders of the human body. The conceptual and mathematical formulations of the problem are discussed. The breathing is considered as a set of synchronized processes of gas dynamics, deformation of the porous medium and diffusion. The results of the calculation of the air flow characteristics during quiet breathing and forced breath in the first four generations of large airways were obtained by using software ANSYS Fluent. Further development of the model involves the joint problem solving of changes in lung configuration and in gasdynamic processes in the human airway.

scholarly journals Linear and nonlinear controllers of a solar photovoltaic water pumping system

2020 ◽  
Vol 9 (5) ◽  
pp. 1861-1872
Author(s):  
M. Madark ◽  
A. Ba-razzouk ◽  
M. El Malah
Keyword(s):  
Mathematical Model ◽  
Induction Motor ◽  
Centrifugal Pump ◽  
Solar Photovoltaic ◽  
Rotor Speed ◽  
Control Laws ◽  
Pumping System ◽  
Water Pumping ◽  
Nonlinear Controllers ◽  
Linear And Nonlinear

This paper provided a comparative study between linear and nonlinear controllers of a solar photovoltaic (PV) water pumping system using an induction motor and a centrifugal pump. For linear controller, classical Perturb and Observe was selected to ensure the operation of the PV system at the maximum power point (MPP) and is combined with Indirect Rotor Field Oriented Control (IRFOC) based on a conventional proportional integral speed regulator chosen to control and to optimize the rotor speed. In second and third controllers, Backstepping and first order sliding mode controls were proposed for controlling the whole system. To regulate and optimize rotor speed in the nonlinear controller, all considered control techniques were combined with IRFOC in order to establish easy control laws. In addition, MPP was tracked by acting on the DC-DC converter and using its mathematical model for developing control laws. Maximum delivered power was used as reference signal for optimizing actual rotor speed. The controlled system is operated without mechanical sensors. Estimators of rotor speed and load torque were proposed based on the mathematical model of induction motor and centrifugal pump and using only available output measurements.. Simulation results were investigated and the effectiveness of the nonlinear proposed strategies.

scholarly journals ANALYSIS OF AIR FLOW DISTRIBUTION IN RESIDENTIAL ROOMS WITH SUPPLY WINDOW VALVES BY MATHEMATICAL MODELING IN ANSYS FLUENT

2019 ◽  
Vol 4 (10) ◽  
pp. 67-73
Author(s):  
О. Симбирев ◽  
O. Simbirev
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Natural Ventilation ◽  
Residential Buildings ◽  
Ventilation System ◽  
Flow Distribution ◽  
Ansys Fluent ◽  
Airflow Distribution ◽  
Standard Values ◽  
Technical Solutions

The main problem highlighted in the article is the deviation of the microclimate parameters from the standard values due to the improper organization of airflow in the residential rooms of apartment buildings. The objective is to obtain a working mathematical model of the natural ventilation system, its study for optimization or modernization. The analysis of the normative literature, scientific works of domestic and foreign scientists, developments in the field of natural ventilation and ventilation of residential buildings is carried out. A mathematical model of air exchange of a residential room with convection is presented and analyzed. The flow rate and air temperature, the temperature on the surface of the heater are set as boundary conditions when creating a mathematical model. The features and regularities of airflow distribution in the room obtained as a result of mathematical modeling are revealed. The distributions of air velocity in the room are given. Difficulties of the organization of effective natural inflow of air and the problems with design of valves of infiltration are designated. Technical solutions aimed at improving the quality of indoor microclimate and energy saving are proposed.

Analytical Modeling of the Bond Behavior between ‎Textile ‎and Mortar Based on Pull-Out ‎Tests

2019 ◽  
Vol 817 ◽  
pp. 112-117 ◽  
Author(s):  
Ali Dalalbashi ◽  
Bahman Ghiassi ◽  
Daniel V. Oliveira
Keyword(s):  
Mathematical Model ◽  
Shear Stress ◽  
Boundary Conditions ◽  
Analytical Modeling ◽  
Relative Slip ◽  
Bond Slip ◽  
Bond Behavior ◽  
Existing Structures ◽  
Pull Out ◽  
The Subject

It is clear that the fiber-to-mortar bond behavior plays a major role on the performance of Textile Reinforced Mortars (TRMs) used for strengthening of existing structures. This aspect, however, has been only the subject of few studies and require further attention.This paper presents an analytical model for extraction of the textile-to-‎mortar bond-slip laws from pull-out tests. The ‎objective is to ‎characterize the parameters that ‎influence the ‎pull-out behavior of TRM ‎systems. ‎In the formulation of the ‎pull-out model, a ‎modified approach ‎based ‎on a mathematical model by Naaman ‎is applied. Firstly, based on ‎the ‎experimental ‎results, a relationship between the bond shear stress and the ‎relative slip ‎along the fiber-mortar ‎interface is obtained. Then, based on the ‎shear stress-slip law, the ‎boundary conditions, equations ‎of equilibrium, and ‎the equation of ‎compatibility and hooke’s ‎law, the bond response ‎between ‎textile and mortar is predicted and modeled.

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