Numerical Simulation of Full-Scale Three-Dimensional Fluid Flow in an Oscillating Reactor

Marine reactors are subjected to additional motions due to ocean conditions. These additional motions will cause large fluctuation of flow rate and change the coolant flow field, making the system unstable. Therefore, in order to understand the effect of oscillating motion on the flow characteristics, a numerical simulation of fluid flow is carried out based on a full-scale three-dimensional oscillating marine reactor. In this study, the resistance coefficients of the lattice, rod buddle and steam generator are fitted, and the distribution of flow rate, velocity as well as pressure in different regions is investigated through the standard model. After additional oscillation is introduced, the flow field in an oscillating reactor is presented and the effect of oscillating angle and elevation on the flow rate is investigated. Results show that the oscillating motion can greatly change the flow field in the reactor; most of the coolant circulates in the downcommer and lower head with only a small amount of coolant entering the core; the flow fluctuation period is consistent with the oscillating period, and the flow variation patterns under different oscillating conditions are basically the same; since the flow amplitude is related to oscillating speed, the amplitude of flow rate rises when decreasing the maximum oscillating angle; the oscillating elevation has little effect on the flow rate.

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Numerical Simulation of Quenchant Flow Characteristics in Large Quench Tank

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.271-272.1372 ◽

2012 ◽

Vol 271-272 ◽

pp. 1372-1376

Author(s):

Hui Sun

Keyword(s):

Fluid Dynamics ◽

Numerical Simulation ◽

Flow Field ◽

Flow Rate ◽

Inner Core ◽

Flow Characteristics ◽

Structure Design ◽

Inner Surface ◽

Computational Fluid Dynamics Cfd

The computational fluid dynamics (CFD) technique is employed to predict the flow of quenchant in a large quench tank. The characteristics of flow field in the existing quench tank are investigated, and the major deficiency occurred in the tank structure design is analyzed. Two different schemes for improving the tank structure design are brought forward, and further numerical simulations are carried out. Results show that the non-uniform flow field is generated throughout the quenching zone in the existing large quench tank. There is clear difference in flow rate in the regions near the inner surface of workpiece and the outer, which may cause the workpiece distortion and even cracking. Reduction in ring pipe intermediate diameter can not obviously enhance the uniformity of flow field in the quench tank. By adding an inner core in the center zone of the tank, the flow rate in the region near the inner surface of workpiece can be increased effectively, and the flow rate difference found in the quenching zone reduced significantly, which are beneficial to guarantee the quenching quality of workpiece.

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Two-Phase Flow Field Numerical Simulation in Scrubber for Exhaust Gas Desulfurization

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.541-542.1288 ◽

2014 ◽

Vol 541-542 ◽

pp. 1288-1291

Author(s):

Zhi Feng Dong ◽

Quan Jin Kuang ◽

Yong Zheng Gu ◽

Rong Yao ◽

Hong Wei Wang

Keyword(s):

Numerical Simulation ◽

Flow Field ◽

Flue Gas ◽

Two Phase Flow ◽

Three Dimensional ◽

Flue Gas Desulfurization ◽

Parameter Design ◽

Phase Flow ◽

Two Phase ◽

Entrance Angle

Calculation fluid dynamics software Fluent was used to conduct three-dimensional numerical simulation on gas-liquid two-phase flow field in a wet flue gas desulfurization scrubber. The k-ε model and SIMPLE computing were adopted in the analysis. The numerical simulation results show that the different gas entrance angles lead to internal changes of gas-liquid two-phase flow field, which provides references for reasonable parameter design of entrance angle in the scrubber.

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Effects of Exhaust Pipe and Diffuser Shapes on Purification Efficiency of Exhaust Gas Three-way Catalyzer for Gasoline Engines - Investigation by Three-dimensional Numerical Simulation of Thermo-fluid Flow and Catalytic Reaction

Marine Engineering ◽

10.5988/jime.44.477 ◽

2009 ◽

Vol 44 (3) ◽

pp. 477-483

Author(s):

Hideki Takase ◽

Toshimasa Kotani ◽

Yogo Takada ◽

Tomoyuki Wakisaka

Keyword(s):

Numerical Simulation ◽

Fluid Flow ◽

Catalytic Reaction ◽

Three Dimensional ◽

Exhaust Pipe ◽

Exhaust Gas ◽

Gasoline Engines ◽

Purification Efficiency

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Full-Scale Numerical Simulation of Plasma-Sprayed Functionally Gradient Materials

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.75.1 ◽

2009 ◽

Vol 75 ◽

pp. 1-6 ◽

Cited By ~ 1

Author(s):

Fu Chi Wang ◽

Qun Bo Fan ◽

Lu Wang ◽

Quan Sheng Wang ◽

Zhuang Ma

Keyword(s):

Numerical Simulation ◽

Three Dimensional ◽

Plasma Jet ◽

Deposition Process ◽

Full Scale ◽

Temperature History ◽

Functionally Gradient Materials ◽

Gradient Materials ◽

Functionally Gradient ◽

Plasma Sprayed

To develop novel and advanced thermal barrier coatings, full-scale numerical simulation of plasma-sprayed functionally gradient materials is conducted in this paper, including the prediction of basic parameters at the nozzle exit, simulation of three dimensional simulation of the plasma jet, modeling of the interaction between the plasma jet and the particles, calculation of flight trajectories and temperature history of flying metal and ceramic particles, the interaction between the molten particles and the substrate, as well as the deposition process of the coatings. Various complex phenomena, such as turbulent effects with chemical reactions in the plasma jet, dispersion status of the particles onto the substrate, and the composition distribution of the functionally gradient materials, are fully taken into account. The numerical simulation results are found to be in good agreement with experimental evidence.

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Numerical Simulation Study on the Recovery Process of Autonomous Underwater Vehicle

10.1115/omae2021-64000 ◽

2021 ◽

Author(s):

Weigang Huang ◽

Donglei Zhang ◽

Jiawei Yu ◽

Tao He ◽

Xianzhou Wang

Keyword(s):

Numerical Simulation ◽

Flow Field ◽

Autonomous Underwater Vehicle ◽

Flow Characteristics ◽

Recovery Process ◽

Underwater Vehicle ◽

Hydrodynamic Performance ◽

Time Step ◽

Convergence Test ◽

Motion Paths

Abstract AUV (Autonomous Underwater Vehicle) recovery is considerably influenced by the nearby flow field and simulations of AUV in different motion paths in the wake of a submarine with a propeller are presented in this paper. A commercial CFD solver STAR CCM+ has been used to research the motion and flow characteristics of AUV, which using the advanced computational continuum mechanics algorithms. The DARPA (Defense Advanced Research Projects Agency) SUBOFF Submarine (L1 = 4.356m) propelled with INSEAN (Italian Ship Model Basin) E1619 propeller is used in this study, and the self-propulsion characteristics of the propeller at an incoming flow velocity of 2.75m/s are obtained through numerical simulation and results are compared with the available experimental data to prove the accuracy of the chosen investigation methodology. A grid/time-step convergence test is performed for verification study. AUV (L2 = 0.4356m) is a smaller-scale SUBOFF without a sail, which approaches the submarine in different motion paths in the submarine wake at a relative speed combined with the dynamic overlapping grid technology. The hydrodynamic performance of the AUV when approaching the submarine and the velocity distribution of the surrounding flow field are analyzed, which provides a useful reference for underwater recovery of the AUV.

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Numerical Simulation and Experimental Verification of the Deposition Concentration of an Unmanned Aerial Vehicle

Applied Engineering in Agriculture ◽

10.13031/aea.13221 ◽

2019 ◽

Vol 35 (3) ◽

pp. 367-376 ◽

Cited By ~ 1

Author(s):

Qiang Shi ◽

Hanping Mao ◽

Xianping Guan

Keyword(s):

Numerical Simulation ◽

Flow Field ◽

Unmanned Aerial Vehicle ◽

Simulation Analysis ◽

Three Dimensional ◽

Laser Scanner ◽

Utilization Rate ◽

Droplet Deposition ◽

Aerial Vehicle ◽

Motion Characteristics

Abstract. To analyze the droplet deposition under the influence of the flow field of an unmanned aerial vehicle (UAV), a hand-held three-dimensional (3D) laser scanner was used to scan 3D images of the UAV. Fluent software was used to simulate the motion characteristics of droplets and flow fields under the conditions of a flight speed of 3 m/s and an altitude of 1.5 m. The results indicated that the ground deposition concentration in the nonrotor flow field was high, the spray field width was 2.6 m, and the droplet deposition concentration was 50 to 200 ug/cm2. Under the influence of the rotor flow field, the widest deposition range of droplets reached 12.8 m. Notably, the droplet deposition uniformity worsened, and the concentration range of the droplet deposition was 0 to 500 ug/cm2. With the downward development of the downwash flow field, the overall velocity of the flow field gradually decreased, and the influence interval of the flow field gradually expanded. In this article, the droplet concentration was verified under simulated working conditions by a field experiment, thereby demonstrating the reliability of the numerical simulation results. This research could provide a basis for determining optimal UAV operating parameters, reducing the drift of droplets and increasing the utilization rate of pesticides. Keywords: Unmanned aerial vehicle (UAV), Aerial application, Downwash flow field, Droplet deposition, Simulation analysis.

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Research on Flow Characteristics of Aerostatic Circular Thrust Bearing with a Cone Cavity

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.308-310.189 ◽

2011 ◽

Vol 308-310 ◽

pp. 189-192

Author(s):

Long Xing Chen ◽

Wen Qi Ma ◽

He Chun Yu ◽

Hai Yan Liu ◽

Hong Wang Du

Keyword(s):

Numerical Simulation ◽

Flow Field ◽

Thrust Bearing ◽

Single Point ◽

Flow Characteristics ◽

Simulation Method ◽

Flow Passage ◽

Testing Method ◽

Measurement Results ◽

Simulation And Experiment

The aerostatic circular thrust bearing was taken as a study subject. The numerical simulation method was used to calculate the flow passage. Meanwhile, the single-point testing method was used to test the pressure distribution. The simulation and experiment measurement results were compared and analyzed. The results show that: The single-point testing method is effective to capture the change of flow characteristics. The overall results of simulation and testing coincide with each other well. In the range of cone cavity, the flow pattern for the gas is turbulent flow, and the flow field should be divided into different zones for simulation.

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