Numerical Seakeeping Simulation of Model Test Condition for Two-Ship Interaction in Waves

2007 ◽  
Author(s):  
Lin Li
Keyword(s):  
Numerical Simulation ◽  
Model Test ◽  
Current Paper ◽  
Free Motion ◽  
Test Results ◽  
Wave Excitation ◽  
Motion Constraints ◽  
Test Conditions ◽  
Motion Modes ◽  
Simulation Results

In order to validate the numerical prediction of two-ship interactions in waves, the model test calibration has to be conducted. However, motion constraints are usually applied when model tests are carried out for the measurement of wave excitation forces and moments in certain selected motion modes for both ships. Therefore, in current paper, a numerical seakeeping simulation of the model test conditions has been studied. Restraints in surge, sway and yaw, as well as the free motion modes in heave, roll and pitch have been all applied to both the ships, experimentally and numerically. The restraint forces and the unrestrained motions have been compared with the model test results and numerical simulation results. Fairly good agreements have been found.

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.

Numerical Simulation of the Kinetic Energy Projectile Oblique Penetration into the Concrete

2014 ◽  
Vol 989-994 ◽  
pp. 982-985
Author(s):  
Jun Chen ◽  
Xiao Jun Ye
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Kinetic Energy ◽  
Three Dimensional ◽  
Test Results ◽  
Destruction Process ◽  
3D Finite Element ◽  
Finite Element Software ◽  
Simulation Results ◽  
Target Characteristics

ANSYS-LS/DYNA 3D finite element software projectile penetrating concrete target three-dimensional numerical simulation , has been the target characteristics and destroy ballistic missile trajectory , velocity and acceleration and analyze penetration and the time between relationship , compared with the test results , the phenomenon is consistent with the simulation results. The results show that : the destruction process finite element software can better demonstrate concrete tests revealed the phenomenon can not be observed , estimated penetration depth and direction of the oblique penetration missile deflection .

Collision Character Research for Semi-Submersible Through Model Test, Simplified Analytical and Numerical Simulation Method

2010 ◽  
Author(s):  
Zhiqiang Hu ◽  
Zhenhui Liu ◽  
Jo̸rgen Amdahl
Keyword(s):  
Numerical Simulation ◽  
Model Test ◽  
Simulation Method ◽  
Tension Force ◽  
Test Results ◽  
Buffer Effect ◽  
Mooring Lines ◽  
Column Structure ◽  
Collision Force ◽  
Energy Absorbing

The characters of the collision scenario when a semi-submersible is struck by a containership are studied in this paper, through the model test, simplified analytical method and numerical simulation. The model test is conducted in the Deepwater Offshore Basin in Shanghai Jiao Tong University. Two special devices are designed to fulfill the model test. One is Ship Launching Device, simplified as SLD, who can launch the striking ship with controllable velocity and in any horizontal direction. The other is Energy Absorbing Device, simplified as EAD, who can simulate the buffer effect of the column structure and collect the collision force as well. A numerical simulation is completed to get the approximate stiffness of the column structure, which is used to adjust the property of EAD. The motions of semi-submersible are obtained, and the collision force and the tension forces of mooring lines are also got. Collision scenario characters for semi-motion and tension force are summarized by the analysis of the model test results. The second collision phenomenon is observed. The collision force dominates the collision moment and the tension force of the mooring lines lags behind. A NTNU in-house program developed by analytical simplified method is also verified by the model test result. The comparison proves the feasibility of the program.

scholarly journals Experimental Research and Numerical Simulation on Grouting Quality of Shield Tunnel Based on Impact Echo Method

2016 ◽  
Vol 2016 ◽  
pp. 1-10
Author(s):  
Fei Yao ◽  
Guangyu Chen ◽  
Jianhong Su
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Working Conditions ◽  
Acoustic Impedance ◽  
Shield Tunnel ◽  
Test Results ◽  
Impact Echo ◽  
Simulation Results ◽  
The Impact ◽  
Impact Echo Method

To identify shield grouting quality based on impact echo method, an impact echo test of segment-grouting (SG) test piece was carried out to explore effect of acoustic impedance of grouting layers and grouting defects on impact echo law. A finite element numerical simulation on the impact echo process was implemented. Test results and simulation results were compared. Results demonstrated that, under some working conditions, finite element simulation results and test results both agree with theoretical values. The acoustic impedance ratio of SG material influenced the echo characteristics significantly. But thickness frequency could not be detected under some working conditions because the reflected energy is weak. Frequency feature under grouting defects was more complicated than that under no grouting defects.

Computer Simulation of a Transportation Package Impacting Concrete and Soil Targets

2004 ◽  
Author(s):  
S. N. Huang ◽  
S. S. Shiraga ◽  
L. M. Hay
Keyword(s):  
Numerical Simulation ◽  
Computer Simulation ◽  
Impact Test ◽  
Impact Behavior ◽  
Test Results ◽  
Hypothetical Accident ◽  
Simulation Results ◽  
Accident Conditions ◽  
The Impact

This paper compares transportation mockup cask impact test results onto real surfaces with FEA numerical simulation results. The impact test results are from a series of cask impact tests that were conducted by Sandia National Laboratories (Gonzales 1987). The Sandia tests were conducted with a half-scale instrumented cask mockup impacting an essentially unyielding surface, in-situ soil, concrete runways, and concrete highways. The cask numerical simulations with these same surfaces are conducted with ABAQUS/Explicit, Version 5.8, The results are then compared and evaluated to access the viability of using numerical simulation to predict the impact behavior of transportation casks under hypothetical accident conditions.

Study on the Porous Media Used in Numerical Simulation of Temperature Characteristic for Isothermal Chambers

2011 ◽  
Vol 291-294 ◽  
pp. 1689-1692
Author(s):  
Li Hong Yang ◽  
Da Hua Liu
Keyword(s):  
Numerical Simulation ◽  
Porous Medium ◽  
Porous Media ◽  
Flow Rate ◽  
Temperature Characteristic ◽  
Test Results ◽  
Temperature Characteristics ◽  
Simulation And Experiment ◽  
Simulation Results ◽  
Metal Wires

Isothermal chamber, which is fabricated by empty chamber stuffed with thin metal wires, is a kind of test devices for flow rate characteristics of pneumatic components, and its temperature characteristics are critical to the accuracy of test results. In this paper, the stuffers in isothermal chamber were considered as porous medium with large porosity, so the temperature characteristics could be studied by numerical simulation. Though there are differences between simulation and experiment, they have same trends and the law of variation can be seen from the simulation results, which demonstrates the reliability of numerical simulation. Consequently, simulation can be an efficient method, which is energy-saving and cost-reducing.

Numerical Simulation of Temperature Effect of Concrete Hydration

2008 ◽  
Vol 400-402 ◽  
pp. 483-488 ◽  
Author(s):  
Lu Wang ◽  
Ying Min Li ◽  
Li Ping Liu ◽  
Shang Ling Xue ◽  
Xun Dai ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Temperature Effect ◽  
Temperature Stress ◽  
Superposition Principle ◽  
Material Behavior ◽  
Test Results ◽  
Heat Generation Rate ◽  
Scaled Model ◽  
Concrete Hydration ◽  
Simulation Results

Based on the improved equation of concrete heat-generation rate and an improved calculation method of temperature stress, the temperature effect of concrete hydration heat is simulated successfully in ANSYS. Comparison between the numerical simulation results and test results of a scaled model of blast furnace foundation indicates that the calculated temperature field based on the improved equation and method is much closer to that of test than which obtained by the old equation and method. By using the stress superposition principle, the temperature-stress field can be calculated with considering the change of material behavior with temperature and time.

Experimental Study on a New Suction Inlet Realizable for Uniform Thickness Collection

2011 ◽  
Vol 308-310 ◽  
pp. 1609-1613
Author(s):  
Si Lin Chen ◽  
Xu Dong Yang ◽  
Shi Qiu ◽  
Chun Lin Ma ◽  
Tao Chen ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Rake Angle ◽  
External Flow ◽  
Test Results ◽  
Uniform Thickness ◽  
Bulk Materials ◽  
Work Surface ◽  
Simulation Results ◽  
Calculation Software

The numerical simulation of flow field of a new rectangular suction inlet installing guide plates with different rake angles was carried out by means of the K-ε turbulence model based on the Fluent hydromechanics calculation software. And that the influences of different rake angles of the internal guide plates on the flow field were analyzed. Consequently, the optimal rake angle of 45° was defined at last. Finally, the practical rectangle suction inlet, according to the numerical simulation results, was developed by installing internal guide plates with the optimal rake angle, which optimizes the distribution of internal and external flow field and improves the average side velocities of flow. Practical test results indicate that the new rectangular suction inlet could realize the uniform thickness collection to achieve the smooth work surface when collecting the bulk materials.

scholarly journals Compressive Behavior of Oil Shale with Calcareous Concretion: Parametric Study

2021 ◽  
Vol 11 (23) ◽  
pp. 11244
Author(s):  
Jinxing Lyu ◽  
Jisen Shu ◽  
Liu Han ◽  
Gerson S. V. Tovele ◽  
Tao Chen
Keyword(s):  
Numerical Simulation ◽  
Oil Shale ◽  
Junggar Basin ◽  
Peak Strength ◽  
Particle Flow Code ◽  
Critical Parameters ◽  
Test Results ◽  
Compressive Behavior ◽  
Calcareous Concretion ◽  
Simulation Results

The non-uniformly distributed calcareous concretion among the oil shale in the Junggar basin of China has led to the difficulty in achieving the slope stability. This paper presents the numerical simulation of the behavior of oil shale with calcareous concretion via the Particle Flow Code (PFC2D) program based on the trial experimental test results. The critical parameters investigated in this research covered the size, distribution, strength, and number of the calcareous concretion. The following conclusions can be drawn based on the discussions and analysis: (1) the hard concretion always results in the high compressive strength of the specimen compared with that without concretion; (2) when the radius of the concretion size raised from 2.5 mm to 20 mm, the peak strength of tested specimens is approximately 50 MPa, whereas, the specimen with large concretion is much more ductile under compression; (3) the compressive behavior of tested specimens is similar even when the position of the concretion is variable; and (4) different from the specimens with only one concretion, these specimens contained two concretions featured with the double “X” failure mode. Meanwhile, the peak strength of the specimens with two hard concretions is about 2.5 times that of its counterparts with two soft concretions. The numerical simulation results are meaningful in guiding the design and analysis of the oil shale slope with the concretion.

Numerical Simulation of Masonry Wall under Explosive Load inside

2013 ◽  
Vol 712-715 ◽  
pp. 909-912 ◽  
Author(s):  
Juan Juan Liu ◽  
Yong Gang Lu ◽  
Jin Song Lei
Keyword(s):  
Numerical Simulation ◽  
Blast Wave ◽  
Masonry Wall ◽  
Rate Of Change ◽  
Von Mises Stress ◽  
Test Results ◽  
Explosive Load ◽  
Contrast Analysis ◽  
Simulation Results ◽  
Von Mises

The explosion process of masonry wall under interior explosive load was simulated by adopting the fluid-solid coupling method basing on the software ANSYS/LS-DYNA. The Von Mises stress nephograms and the contrast analysis of the numerical simulation results and test results were presented. The research indicates that mortar elements fails earlier than brick, a little difference exists between the sizes of the blasting hole in X and Y direction because of the transmission of blast wave in brick masonry, the size of blasting hole grows with the increase of weight of charge, and with the increasing charge, the rate of change declined gradually.

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