scholarly journals Compliance of a rigid joint of a steel column of I-section on a rigid foundation

2019 ◽  
Vol 265 ◽  
pp. 05035
Author(s):  
Pavel Morozovskiy ◽  
Egor Kanaev ◽  
Nikita Kryzhanovskii ◽  
Rafik Al Malul
Keyword(s):  
Numerical Simulation ◽  
Compressive Load ◽  
Rigid Foundation ◽  
Computer Complex ◽  
Numerical Studies ◽  
Steel Column ◽  
Anchor Bolts ◽  
Foundation Plate

The article considers the compliance of a rigid assembly of a steel column of a typical I-section under the loads of an eccentric-compressive load with a random eccentricity. A simplified scheme of pinching a rigid hinge is considered as well as its detailed version in which the rigid part of the rod is elaborated as a basement, foundation plate, cross-arm and anchor bolts with plates. The authors carried out numerical studies of this site using a computer complex Abaqus 2017. Analysis of the results showed that the inclusion of compliance at a sufficiently accurate numerical simulation gives the same value for compressive forces. Thus, this node can be considered rigid, and the coefficient of buckling is almost equal to the theoretical value.

The Primary Discussion of Blade Sections for Application of Helium Compressor

2008 ◽  
Author(s):  
Yu E. Liu ◽  
Yufeng Sun
Keyword(s):  
Numerical Simulation ◽  
Size Range ◽  
Simulation Models ◽  
Compressor Blade ◽  
Working Fluid ◽  
Numerical Studies ◽  
Cascade Flow ◽  
Compressor Design ◽  
Inlet Conditions ◽  
Similarity Relationships

The investigation of the airfoil is a key design issue in the development and deployment of helium compressor for High Temperature Gas Cooled Reactor. As the helium physical properties are different from the air’s, three flow cases are studied to find out the similarities between helium and air using Fluent in this paper. They are flow within the divergent nozzles, flow around cylinders and flow over cascades under same inlet conditions and geometry. The results indicated some similarity relationships between helium and air cascade flow. NACA 65-(12A10)10 compressor blade was used as sample blade for both air and helium cascades. To test the performance of the blades, calculations were carried out under the condition of kinematics similitude, but different working fluid. The numerical simulation results of air cascades are correlated with NACA experiment results of air subsonic cascades very well. The numerical simulation models for the air subsonic cascades were used to test the performance of similar helium cascades. The cascade performance for helium flows were compared with the air flows and the results are presented in this paper. The purpose of numerical studies is to use blades in the current air compressor as the blades for helium compressor, to develop scaling blades in NACA 65-(12A10)10 blade size range, and to identify practical limitations to the scaling of current conventional blades. The analysis and conclusions presented in this paper can be used as a reference to helium compressor design features and the experimental research works.

scholarly journals Numerical Simulation of Cavitation and Aeration in Discharge Gated Tunnel of a Dam Based on the VOF Method

2011 ◽  
Vol 110-116 ◽  
pp. 2754-2761
Author(s):  
Razieh Jalalabadi ◽  
Norouz Mohammad Nouri
Keyword(s):  
Numerical Simulation ◽  
Cavitation Erosion ◽  
Vof Method ◽  
Bubbly Flows ◽  
Hydraulic Structures ◽  
Cavitating Flows ◽  
Effective Protection ◽  
Two Phase ◽  
Cavitation Inception ◽  
Numerical Studies

Cavitation, usually known as a destructive phenomenon, involves turbulent unsteady two-phase flow. Having such features, cavitating flows have been turned to a challenging topic in numerical studies and many researches are being done for better understanding of bubbly flows and proposing solutions to reduce its consequent destructive effects. Aeration may be regarded as an effective protection against cavitation erosion in many hydraulic structures, like gated tunnels. The paper concerns numerical simulation of flow in discharge gated tunnel of a dam using RNG model coupled with the volume of fluid (VOF) method and the zone which is susceptible of cavitation inception in the tunnel is predicted. Then a vent is considered in the mentioned zone for aeration and the numerical simulation is done again to study the effects of aeration. The results show that aeration is an impressively useful method to exclude cavitation in mentioned tunnels.

scholarly journals Effect of the Flow of Large Water Droplets on the Water Mist Sprays

2014 ◽  
Vol 2 (2) ◽  
pp. 27-37
Author(s):  
László Beda ◽  
Csaba Szikra
Keyword(s):  
Numerical Simulation ◽  
Velocity Field ◽  
Large Diameter ◽  
Water Mist ◽  
Cfd Model ◽  
Water Droplets ◽  
Numerical Studies ◽  
Dynamic Simulator ◽  
Fire Dynamic Simulator ◽  
Large Water

Abstract The purpose of this study is to investigate the velocity field generated by water droplets with relatively large diameter that has great effect on the movement of several orders of magnitude smaller particles. A CFD model, Fire Dynamic Simulator (FDS) version 5.5.3 was used for the numerical simulation. The data obtained from the numerical studies are analysed.

Numerical Study of the Pressure Drop in a Flame Arrestor Using a Porous Media Model

2020 ◽  
Author(s):  
Hoden A. Farah ◽  
Frank K. Lu ◽  
Jim L. Griffin
Keyword(s):  
Numerical Simulation ◽  
Porous Media ◽  
Numerical Study ◽  
Flow Characteristics ◽  
Small Scale ◽  
Forchheimer Equation ◽  
Flow Equations ◽  
Numerical Studies ◽  
Porous Media Model ◽  
Empirical Coefficients

Abstract A numerical study of the flow characteristics of a crimped flame arrestor element was conducted using a porous media model. The porous zone was modeled using the Forchheimer equation. The Forchheimer equation was incorporated into the governing conservation equations as a momentum sink. A small-scale crimped flame arrestor element was tested to determine the empirical coefficients in the Forchheimer equation. The numerical simulation result using this porous media model was verified using experimental data. The flow characteristics of a four-inch detonation flame arrestor with the same crimp design as the small-scale sample, was simulated using the porous media model. The numerical simulation flow data were compared against experimental values and agreed to within five percent. The method used to determine the Forchheimer coefficients and the experimental test setup are described in detail. The application of the Forchheimer equation into the governing flow equations is presented. The challenges and limitation of numerical studies in flame arrestors applications are discussed. The simplification gained by using the porous media model in flame arrestor numerical studies is presented.

scholarly journals Removal of moisture from contaminated transformer oil in rectangular separators

2019 ◽  
Vol 110 ◽  
pp. 01026 ◽  
Author(s):  
Andrey Dmitriev ◽  
Vadim Zinurov ◽  
Dang Vinh ◽  
Oksana Dmitrieva
Keyword(s):  
Numerical Simulation ◽  
Separation Efficiency ◽  
Transformer Oil ◽  
Ansys Fluent ◽  
Oil Emulsion ◽  
Numerical Studies ◽  
Emulsion Separation ◽  
Fluent Software ◽  
Object Of Study ◽  
Geometrical Dimensions

This paper deals with the removal of moisture from the contaminated transformer oil. Design of a rectangular separator and the results of water-oil emulsion separation are shown in this paper. The influence of different values of the separator height and the distance between the rows of elements on the emulsion separation efficiency was studied. In order to calculate the process of removing the moisture from transformer insulating oil, the multiphase Eulerian-Eulerian model “Volume of Fluid” with the number of phases equal to 2 was applied in ANSYS Fluent software package. K–ε turbulence model was used for the calculations. The results were obtained while solving the nonstationary issue. In the course of numerical simulation, the object of study was the transformer oil T-1500U, containing some water amount. The results of numerical simulation of water-oil emulsion separation in a rectangular separator are shown. In the course of numerical studies, it was found that the use of a rectangular separator in order to remove the moisture from transformer oil allows it to be purified from water by 99.99%, providing that the geometrical dimensions of device are chosen correctly. The use of developed rectangular separator can be an alternative to the use of decanting tanks, various separators and other purification devices, which have extremely low rate of purification of contaminated spent oils. This separator allows purifying the transformer oil from water with a speed of 1-2 m/s while the efficiency is equal to 99.99%.

scholarly journals Synchronized Attractors and Phase Entrained with Cavity Loss of the Coupled Laser’s Map

2022 ◽  
Author(s):  
Abdul Abdul ◽  
Altaf Ur Rahman ◽  
Chen Minjing ◽  
Jehan Akbar ◽  
Farhan Saif ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Differential Equations ◽  
Symmetry Breaking ◽  
Coupling Strength ◽  
Strange Attractors ◽  
Chaotic Attractors ◽  
Cavity Loss ◽  
Numerical Studies ◽  
Coupled Maps ◽  
Basin Boundaries

The laser differential equations are used to transform them into identical coupled maps. Valuable results are deduced during analytical and numerical studies on cavity loss. Phase and spatiotemporal synchronized attractors are observed via quasi-chaos under a certain range of controlling parameters, and symmetry breaking of chaotic attractors due to collision with their basin boundaries, and transpire differently from the previous attractors. During the numerical simulation, it is found that the sequence of repeated strange attractors if the coupling strength further increases, which are orthogonal mirror images (the dynamics of the system is the same at different values of controlling parameters). Moreover, it can help us to predict future problems and their solutions based on current issues, if we develop this model in more general.

scholarly journals Numerical Simulation of Hot Jet Detonation with Different Ignition Positions

2019 ◽  
Vol 9 (21) ◽  
pp. 4607 ◽  
Author(s):  
Zheng ◽  
Liu ◽  
Zhao ◽  
Chen ◽  
Jia ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Detonation Wave ◽  
Energy Release ◽  
Detonation Initiation ◽  
Navier Stokes ◽  
Jet Formation ◽  
Jet Flame ◽  
Numerical Studies ◽  
Detonation Transition ◽  
Accelerating Energy Release

Ignition position is an important factor affecting flame propagation and deflagration-to-detonation transition (DDT). In this study, 2D reactive Navier–Stokes numerical studies have been performed to investigate the effects of ignition position on hot jet detonation initiation. Through the stages of hot jet formation, vortex-flame interaction and detonation wave formation, the mechanism of the hot jet detonation initiation is analyzed in detail. The results indicate that the vortexes formed by hot jet entrain flame to increase the flame area rapidly, thus accelerating energy release and the formation of the detonation wave. With changing the ignition position from top to wall inside the hot jet tube, the faster velocity of hot jet will promote the vortex to entrain jet flame earlier, and the DDT time and distance will decrease. In addition, the effect of different wall ignition positions (from 0 mm to 150 mm away from top of hot jet tube) on DDT is also studied. When the ignition source is 30 mm away from the top of hot jet tube, the distance to initiate detonation wave is the shortest due to the highest jet intensity, the DDT time and distance are about 41.45% and 30.77% less than the top ignition.

scholarly journals Determination of the Electromagnetic Field on the Surface of the Beam Splitter of Laser Interferometer by Measuring the Displacements of Control Object Surfaces

2018 ◽  
Vol 8 (11) ◽  
pp. 2137 ◽  
Author(s):  
Igor Miroshnichenko ◽  
Ivan Parinov ◽  
Shun-Hsyung Chang ◽  
Hung-Yu Wang
Keyword(s):  
Numerical Simulation ◽  
Electromagnetic Field ◽  
Beam Splitter ◽  
Laser Interferometer ◽  
Control Object ◽  
Numerical Studies ◽  
Simulation Results ◽  
Optical Circuits ◽  
Theoretical Results

The paper describes in detail the governing relationships for the electromagnetic field on the surface of the laser beam splitter of a laser interferometer. These expressions are intended for numerical simulation of measuring the displacements of control object surfaces by using a laser interferometer. We consider the cases of perpendicular and parallel polarizations of the radiation source. Moreover, the most relevant particular cases of constructing optical circuits of the interferometer in question are treated. The presented theoretical results have been used in numerical studies of the functional characteristics of promising contactless optical means of measuring displacements. The use of the described results has improved the quality and informativeness of the numerical simulation results of the measurement process of displacements by a laser interferometer.

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