scholarly journals Numerical Simulation of the Perforated Shell’s Oscillations in a Vibrational Priller

2020 ◽  
Vol 7 (2) ◽  
pp. F30-F36
Author(s):  
M. Demianenko ◽  
M. Volf ◽  
M. Skydanenko ◽  
V. Yakovchuk ◽  
I. Pavlenko ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Raw Materials ◽  
Sol Gel ◽  
Cylindrical Body ◽  
Vibration Effect ◽  
Vibrational Characteristics ◽  
Hydromechanical System ◽  
Simulation Results ◽  
Discrete Mathematical Model ◽  
Stiffness And Damping

The widespread catalysts and nuclear fuel production are the sol-gel technology, including several stages, namely, the raw materials preparation, dispersing it into drops, the granules formation in gas and then in liquid media, granules removal with liquid separation. The vibration granulator is proposed to use on the dispersion stage. One of the problems in their development is determining the vibrational characteristics of a perforated bucket filled with liquid to a certain level. Considering that vibrations are transmitted from the emitter disk through the liquid melt and cause vibrations of the perforated shell, in research, it was decided to use the Fluent Flow and the Transient Structural modules of the ANSYS Workbench software. As a result, numerical simulation results of the emitter disk vibration effect on the cylindrical body are presented. Also, parameters of a discrete mathematical model are evaluated by the bucket vibrations characteristics. The corresponding model considers the inertial, stiffness, and damping properties of functional elements. Additionally, according to the modal analysis results of the priller body, it was determined the eigenfrequencies of the hydromechanical system. Finally, based on the numerical simulation results and their analysis using Fourier transformations, it was determined that the oscillations of the lower part of the bucket, consisting of two harmonic oscillations that equal 230 Hz and 520 Hz.

scholarly journals Research on Damping Characteristics of Interconnected Hydropneumatic Suspension considering the Effects of Hose and Check Valve

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Hongmin Zhang ◽  
Xin Fang
Keyword(s):  
Numerical Simulation ◽  
Energy Method ◽  
Damping Ratio ◽  
Check Valve ◽  
Nonlinear Stiffness ◽  
Calculation Formula ◽  
Damping Force ◽  
Damping Characteristics ◽  
Simulation Results ◽  
Stiffness And Damping

The interconnected hydropneumatic suspension (ICHPS) has not only the nonlinear stiffness and damping of the independent hydropneumatic suspension (IDHPS) but also antiroll and antipitch functions. The existing analysis of hydropneumatic suspension damping mainly focuses on the orifice and check valve in the suspension cylinder. In this study, the calculation formula of the damping force of ICHPS is established, and the numerical simulation results show that the damping characteristics of the hydraulic hose cannot be ignored. The influence of check valve and hose on the damping characteristics is analyzed. Through the equivalent energy method, the equivalent compression damping ratio and the equivalent recovery damping ratio of the ICHPS are established. It is pointed out that when designing the damping characteristics of the ICHPS, it is necessary to select the orifices, check valves, and hose damping reasonably to make the damping characteristics get the best match.

Epitaxial Growth of Sr0.3Ba0.7Nb2O6 Thin Films Prepared by Sol-Gel Process

1999 ◽  
Vol 606 ◽  
Author(s):  
Keishi Nishio ◽  
Jirawat Thongrueng ◽  
Yuichi Watanabe ◽  
Toshio Tsuchiya
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Epitaxial Growth ◽  
Raw Materials ◽  
Substrate Surface ◽  
Sol Gel ◽  
Tungsten Bronze ◽  
Monomethyl Ether ◽  
Tetragonal Tungsten Bronze ◽  
Sol Gel Process

AbstructWe succeeded in the preparation of strontium-barium niobate (Sr0.3Ba0.7Nb2O6 : SBN30)that have a tetragonal tungsten bronze type structure thin films on SrTiO3 (100), STO, or La doped SrTiO3 (100), LSTO, single crystal substrates by a spin coating process. LSTO substrate can be used for electrode. A homogeneous coating solution was prepared with Sr and Ba acetates and Nb(OEt)5 as raw materials, and acetic acid and diethylene glycol monomethyl ether as solvents. The coating thin films were sintered at temperature from 700 to 1000°C for 10 min in air. It was confirmed that the thin films on STO substrate sintered above 700°C were in the epitaxial growth because the 16 diffraction spots were observed on the pole figure using (121) reflection. The <130> and <310> direction of the thin film on STO were oriented with the c-axis in parallel to the substrate surface. However, the diffraction spots of thin film on LSTO substrate sintered at 700°C were corresponds to the expected pattern for (110).

Avalanche Features in Silicon Schottky-FETs in Accordance with Numerical Simulation Results

2006 ◽  
Vol 65 (16) ◽  
pp. 1533-1546
Author(s):  
Yu. Ye. Gordienko ◽  
S. A. Zuev ◽  
V. V. Starostenko ◽  
V. Yu. Tereshchenko ◽  
A. A. Shadrin
Keyword(s):  
Numerical Simulation ◽  
Simulation Results

Tail shapes lead to different propulsive mechanisms in the body/caudal fin undulation of fish

2020 ◽  
pp. 095440622096768
Author(s):  
Jialei Song ◽  
Yong Zhong ◽  
Ruxu Du ◽  
Ling Yin ◽  
Yang Ding
Keyword(s):  
Numerical Simulation ◽  
Aspect Ratio ◽  
High Efficiency ◽  
The Body ◽  
Caudal Fin ◽  
Fish Model ◽  
Swimming Efficiency ◽  
Simulation Results ◽  
Propulsive Mechanism ◽  
High Depth

In this paper, we investigate the hydrodynamics of swimmers with three caudal fins: a round one corresponding to snakehead fish ( Channidae), an indented one corresponding to saithe ( Pollachius virens), and a lunate one corresponding to tuna ( Thunnus thynnus). A direct numerical simulation (DNS) approach with a self-propelled fish model was adopted. The simulation results show that the caudal fin transitions from a pushing/suction combined propulsive mechanism to a suction-dominated propulsive mechanism with increasing aspect ratio ( AR). Interestingly, different from a previous finding that suction-based propulsion leads to high efficiency in animal swimming, this study shows that the utilization of suction-based propulsion by a high- AR caudal fin reduces swimming efficiency. Therefore, the suction-based propulsive mechanism does not necessarily lead to high efficiency, while other factors might play a role. Further analysis shows that the large lateral momentum transferred to the flow due to the high depth of the high- AR caudal fin leads to the lowest efficiency despite the most significant suction.

scholarly journals Experiment and simulation about the effect of wear-ring abrasion on the performance of a marine centrifugal pump

2021 ◽  
Vol 13 (2) ◽  
pp. 168781402199811
Author(s):  
Wu Xianfang ◽  
Du Xinlai ◽  
Tan Minggao ◽  
Liu Houlin
Keyword(s):  
Numerical Simulation ◽  
Centrifugal Pump ◽  
Pressure Pulsation ◽  
Vibration Velocity ◽  
Test Results ◽  
Obvious Effect ◽  
Performance Change ◽  
Pump Test ◽  
Simulation Results ◽  
Axis Passing

The wear-ring abrasion can cause performance degradation of the marine centrifugal pump. In order to study the effect of front and back wear-ring clearance on a pump, test and numerical simulation were used to investigate the performance change of a pump. The test results show that the head and efficiency of pump decrease by 3.56% and 9.62% respectively at 1.0 Qd due to the wear-ring abrasion. Under 1.0 Qd, with the increase of the front wear-ring the vibration velocity at pump foot increases from 0.4 mm/s to 1.0 mm/s. The axis passing frequency (APF) at the measuring points increases significantly and there appears new characteristic frequency of 3APF and 4APF. The numerical simulation results show that the front wear-ring abrasion affects the flow at the inlet of the front chamber of the pump and impeller passage. And the back wear-ring abrasion has obvious effect on the flow in the back chamber of the pump and impeller passage, while the multi-malfunction of the front wear-ring abrasion and back wear-ring abrasion has the most obvious effect on the flow velocity and flow stability inside pump. The pressure pulsation at Blade Passing Frequency (BPF) of the three schemes all decrease with the increase of the clearance.

scholarly journals Development of Depth-Limited Wave Boundary Layers over a Smooth Bottom

2020 ◽  
Vol 9 (1) ◽  
pp. 27
Author(s):  
Hitoshi Tanaka ◽  
Nguyen Xuan Tinh ◽  
Xiping Yu ◽  
Guangwei Liu
Keyword(s):  
Numerical Simulation ◽  
Boundary Layer ◽  
Boundary Layers ◽  
Wave Motion ◽  
Numerical Study ◽  
Experiment Data ◽  
Tidal Motion ◽  
Long Period ◽  
Simulation Results ◽  
Wave Boundary

A theoretical and numerical study is carried out to investigate the transformation of the wave boundary layer from non-depth-limited (wave-like boundary layer) to depth-limited one (current-like boundary layer) over a smooth bottom. A long period of wave motion is not sufficient to induce depth-limited properties, although it has simply been assumed in various situations under long waves, such as tsunami and tidal currents. Four criteria are obtained theoretically for recognizing the inception of the depth-limited condition under waves. To validate the theoretical criteria, numerical simulation results using a turbulence model as well as laboratory experiment data are employed. In addition, typical field situations induced by tidal motion and tsunami are discussed to show the usefulness of the proposed criteria.

Sol-Gel Synthesis and Characterization of Ultrafine ZrSiO4 Powder

2014 ◽  
Vol 906 ◽  
pp. 66-71
Author(s):  
Zhen Quan Li ◽  
Qiang Zhen ◽  
Ya Li Wang
Keyword(s):  
Wavelength Range ◽  
High Purity ◽  
Raw Materials ◽  
Formation Rate ◽  
Sol Gel ◽  
Molar Ratio ◽  
Sem And Tem ◽  
Homogeneous Product ◽  
Sol Gel Synthesis ◽  
Calcined Temperature

High purity ZrSiO4 powder were synthesized using Si (C2H5O)4 and ZrOCl2·8H2O as raw materials by the sol-gel method, LiCl was added as mineralizer to promote crystallization of zircon. The influences of molar ratio of Zr:Si, calcined time and calcined temperature on the synthesis of ZrSiO4 powder were investigated. XRD, SEM and TEM were used to characterize the powders. It was found that when the molar ratio of Zr:Si was 1:1.2, the calcined temperature was 1600°C and the calcined time was 4h, the high purity ZrSiO4 ultrafine powder was obtained. The ZrSiO4 formation began at 1300°C and when the gel was calcined at 1600°Cfor 4 h, the formation rate of ZrSiO4 was up to 95%. SEM and TEM studies reveal a homogeneous product with particle sizes on the order of 0.1-1μm. The IR emissivity of ultrafine ZrSiO4 is 0.892 at the whole wavelength range, and that is up to 0.951 at the wavelength range of 8-14 μm.

Design of Impeller of Centrifugal Compressor for Water-Air Engine

2014 ◽  
Vol 496-500 ◽  
pp. 642-645
Author(s):  
Yun Wang ◽  
Wei Zhang
Keyword(s):  
Numerical Simulation ◽  
Power System ◽  
Centrifugal Compressor ◽  
Centrifugal Impeller ◽  
3D Design ◽  
Pump Impeller ◽  
Aero Engine ◽  
Simulation Results

In view of power system in water-air UAV requirements, combine with the centrifugal impeller for aero-engine and the pump impeller. The design of a impeller of centrifugal compressor can work on the air and in the water for the new concept of air-water engine. With 3D design and a 3D CFD solver on it and analysis the results of numerical simulation. Results show that the designed impeller successfully reached the goal on the air and in the water. The experiences accumulated in this procedure are useful for similar impeller aerodynamic designs.

Numerical simulation of the liquid phase in SnO2 thin film deposition by sol-gel-dip-coating

2010 ◽  
Vol 55 (3) ◽  
pp. 385-393 ◽  
Author(s):  
Dayene M. Carvalho ◽  
Jorge L. B. Maciel ◽  
Leandro P. Ravaro ◽  
Rogério E. Garcia ◽  
Valdemir G. Ferreira ◽  
...  
Keyword(s):  
Thin Film ◽  
Numerical Simulation ◽  
Liquid Phase ◽  
Sol Gel ◽  
Thin Film Deposition ◽  
Dip Coating ◽  
Film Deposition ◽  
Sno2 Thin Film

The Influence of the Convective Terms Discretization Scheme on the Simulation Results of Architectural Numerical Wind Tunnel

2012 ◽  
Vol 204-208 ◽  
pp. 4884-4887
Author(s):  
Jian Feng Wu ◽  
Cai Hua Wang ◽  
Chang Li Song
Keyword(s):  
Numerical Simulation ◽  
Wind Tunnel ◽  
Building Structures ◽  
Discretization Scheme ◽  
Shape Coefficient ◽  
Fluent Software ◽  
Actual Operation ◽  
Simulation Results ◽  
Load Shape ◽  
Numerical Wind Tunnel Method

The numerical simulation of construction is to obtain the desired accuracy. It depends on the theoretical basis of the calculator and selection of the various important factors in the actual operation. For this problem, this paper adopting the current code for the design of building structures as the comparison standard, using the FLUENT software, taking the numerical simulation results of a high building’s wind load shape coefficient of for example, discussing the influence of four kinds of the convective terms discretization scheme, respectively the first-order upwind, the second order upwind , power law and Quadratic upwind interpolation for convective kinematics, on the simulation results of architectural numerical wind tunnel, provides the reference for the rational use of numerical wind tunnel method.

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