Study on the Influence of Ice-Water Coupling on Numerical Calculation of Ice Load

2018 ◽  
Author(s):  
Hui Li ◽  
Zheng Yang ◽  
Yan Feng ◽  
Yu-Bo Wang ◽  
Si-Yu Wang
Keyword(s):  
Numerical Simulation ◽  
Numerical Calculation ◽  
Sea Ice ◽  
Sea Water ◽  
Coupling Effect ◽  
Simulation Software ◽  
Ice Load ◽  
Local Strength ◽  
Ice Water ◽  
The Impact

The interaction between sea ice and sea water is a complicated fluid-solid coupling dynamic process during the operation of polar ships. Using the finite element numerical simulation software LS-DYNA to simulate the continuous ice breaking of icebreaker, the ice load numerical calculation method considering the ice water coupling is presented. The effect of ice water coupling on ice load is studied. Based on the ice pool test data and the calculated results of this paper, the accuracy and rationality of the algorithm are verified. On this basis, the multiple factors affecting the coupling between sea ice and sea water are further studied, including the thickness of sea ice and the collision velocity of ship and ice which are affected by the environment of different polar sea areas. By simulating the numerical results obtained from the collision ice breaking of the targeted ship, the influence of various factors on the coupling effect between sea ice and sea water is summarized, and the local strength of the hull head structure is checked and evaluated. Furthermore, the impact-type icebreaking ability of the hull is put forward, which has certain guiding significance for the development of ship ice collision numerical simulation.

scholarly journals Tank study of physico-chemical controls on gas content and composition during growth of young sea ice

2002 ◽  
Vol 48 (161) ◽  
pp. 177-191 ◽  
Author(s):  
Jean-Louis Tison ◽  
Christian Haas ◽  
Marcia M. Gowing ◽  
Suzanne Sleewaegen ◽  
Alain Bernard
Keyword(s):  
Sea Ice ◽  
Sea Water ◽  
Bubble Nucleation ◽  
Water Dynamics ◽  
Gas Content ◽  
First Year ◽  
Water Interface ◽  
Atmospheric Gases ◽  
Physico Chemical ◽  
Ice Water

AbstractDuring an ice-tank experiment, samples were taken to study the processes of acquisition and alteration of the gas properties in young first-year sea ice during a complete growth–warming–cooling cycle. The goal was to obtain reference levels for total gas content and concentrations of atmospheric gases (O2, N2, CO2) in the absence of significant biological activity. The range of total gas-content values obtained (3.5–18 mL STP kg−1) was similar to previous measurements or estimates. However, major differences occurred between current and quiet basins, showing the role of the water dynamics at the ice–water interface in controlling bubble nucleation processes. Extremely high CO2concentrations were observed in all the experiments (up to 57% in volume parts). It is argued that these could have resulted from two unexpected biases in the experimental settings. Concentrations in bubbles nucleated at the interface are controlled by diffusion both from the ice–water interface towards the well-mixed reservoir and between the interface water and the bubble itself. This double kinetic effect results in a transition of the gas composition in the bubbles from values close to solubility in sea water toward values close to atmospheric, as the ice cover builds up.

scholarly journals The Formation of Brine Drainage Features in Young Sea Ice

1975 ◽  
Vol 14 (70) ◽  
pp. 137-154 ◽  
Author(s):  
Lars Ingolf Eide ◽  
Seelye Martin
Keyword(s):  
Sea Ice ◽  
Laboratory Experiments ◽  
Sea Water ◽  
Salt Water ◽  
Pressure Head ◽  
Drainage Channels ◽  
The Difference ◽  
Thin Plastic ◽  
Ice Water ◽  
Brine Channel

Laboratory experiments on the growth of sea ice in a very thin plastic tank filled with salt water, cooled from above and insulated with thermopane, clearly show the formation and development of brine drainage channels. The sea-water freezing cell is 0.3 cm thick by 35 cm wide by 50 cm deep; the thermopane insulation permits the ice interior to be photographed. Experimentally, we observe that vertical channels with diameters of 1 to 3 mm and associated smaller feeder channels extend throughout the ice sheet. Close examination of the brine channels show that their diameter at the ice-water interface is much narrower than higher up in the ice, so that the channel has a “neck” at the interface. Further, oscillations occur in the brine channels, in that brine flows out of the channel followed by a flow of sea-water up into the channel. Theoretically, a qualitative theory based on the difference in pressure head between the brine inside the ice and the sea-water provides a consistent explanation for the formation of the channels, and the onset of a convective instability explains the existence of the neck. Finally, an analysis based on the presence of the brine-channel neck provides an explanation for the observed oscillations.

The Impact on the Pier of Shaped Charge Ice-Breaking and Numerical Simulation Analysis

2014 ◽  
Vol 501-504 ◽  
pp. 1883-1887
Author(s):  
Wen Yuan Meng ◽  
Jia Qing Li ◽  
Ying Kui Guo ◽  
Guan Chao Xu ◽  
Jun Wei Guo
Keyword(s):  
Numerical Simulation ◽  
Reinforced Concrete ◽  
Maximum Stress ◽  
Simulation Analysis ◽  
Shaped Charge ◽  
Ice Water ◽  
The Impact

In the process of shaped charge ice-breaking , the response of piers is great under the impact of air, ice, water etc, and relates to integral security of the bridge. For the impact on the pier with burst points of the different distances is simulated by ANSYS / DYNA software, summarizes the impact on the pier of shaped charge ice-breaking, and obtains the maximum stress curves of the pier at different distances. Simultaneously, the paper analyses critical damaging- model of the C30 reinforced concrete piers in detail. The conclusion has a major role in guiding when shaped charge ice-breaking appears.

scholarly journals The Formation of Brine Drainage Features in Young Sea Ice

1975 ◽  
Vol 14 (70) ◽  
pp. 137-154 ◽  
Author(s):  
Lars Ingolf Eide ◽  
Seelye Martin
Keyword(s):  
Sea Ice ◽  
Laboratory Experiments ◽  
Sea Water ◽  
Salt Water ◽  
Pressure Head ◽  
Drainage Channels ◽  
The Difference ◽  
Thin Plastic ◽  
Ice Water ◽  
Brine Channel

Laboratory experiments on the growth of sea ice in a very thin plastic tank filled with salt water, cooled from above and insulated with thermopane, clearly show the formation and development of brine drainage channels. The sea-water freezing cell is 0.3 cm thick by 35 cm wide by 50 cm deep; the thermopane insulation permits the ice interior to be photographed. Experimentally, we observe that vertical channels with diameters of 1 to 3 mm and associated smaller feeder channels extend throughout the ice sheet. Close examination of the brine channels show that their diameter at the ice-water interface is much narrower than higher up in the ice, so that the channel has a “neck” at the interface. Further, oscillations occur in the brine channels, in that brine flows out of the channel followed by a flow of sea-water up into the channel. Theoretically, a qualitative theory based on the difference in pressure head between the brine inside the ice and the sea-water provides a consistent explanation for the formation of the channels, and the onset of a convective instability explains the existence of the neck. Finally, an analysis based on the presence of the brine-channel neck provides an explanation for the observed oscillations.

scholarly journals Dynamics and Impacting Factors of Ice Regimes in Latvia Inland and Coastal Waters

2016 ◽  
Vol 70 (6) ◽  
pp. 400-408 ◽  
Author(s):  
Māris Kļaviņš ◽  
Zanita Avotniece ◽  
Valērijs Rodinovs
Keyword(s):  
Climate Change ◽  
Sea Ice ◽  
North Atlantic ◽  
Sea Water ◽  
Inland Waters ◽  
The North ◽  
The North Atlantic ◽  
Ice Regime ◽  
The Impact

Abstract The sea ice regime is considered to be a sensitive indicator of climate change. This study investigates long-term changes in the ice regimes of the Gulf of Riga along the coast of Latvia in comparison with those of inland waters. The ice regime of the studied region indicates the impact of climate change related to increasing air and sea water temperatures. Ice cover duration on both the sea and inland waters has decreased during recent decades. In addition, long-term records on ice break in the studied region exhibit a pattern of periodic changes in the intensity of ice regime, while trends of the sea ice regime are not consistent between periods of time. Alternating mild and severe winters also occur. The ice regime was shown to be strongly influenced by large-scale atmospheric circulation processes over the North Atlantic, as indicated by close correlation with the North Atlantic Oscillation index.

Numerical Studies on Low-Velocity Impact Failure Response of Al 1100 under Blunt and Hemispherical Impactors

2018 ◽  
Vol 917 ◽  
pp. 218-222 ◽  
Author(s):  
Sonika Sahu ◽  
Mohd Zahid Ansari ◽  
Chong Du Cho
Keyword(s):  
Numerical Simulation ◽  
Impact Analysis ◽  
Failure Modes ◽  
Simulation Software ◽  
Low Velocity Impact ◽  
Impact Behavior ◽  
Nose Radius ◽  
Low Velocity ◽  
Velocity Impact ◽  
The Impact

Numerical simulation is performed to study the deformation and failure modes of Al 1100 plate of 2.4 mm thickness, subjected to low-velocity impact. Blunt and hemispherical nose shaped impactors are used in this study. The quasi-static tensile test is performed at a strain rate of 0.01/s to obtain the Johnson-Cook material parameters which are used in numerical simulation software, ABAQUS/CAE to perform impact analysis. Mesh convergence study is carried out to decide the appropriate number of elements for numerical analysis. The impact behavior of Al 1100 plate for each impactor shapes are studied at 22 J impact energy. Result indicate that increased in the nose radius of impactor will increase the amount of deformation energy for aluminium plate.

scholarly journals Effect of Seepage Velocity on Formation of Shaft Frozen Wall in Loose Aquifer

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Jian Lin ◽  
Hua Cheng ◽  
Hai-bing Cai ◽  
Bin Tang ◽  
Guang-yong Cao
Keyword(s):  
Numerical Simulation ◽  
Optimization Design ◽  
Coupling Effect ◽  
Measurement Data ◽  
Freezing Process ◽  
Seepage Velocity ◽  
Finite Element Software ◽  
Frozen Wall ◽  
Simulation Results ◽  
The Impact

This paper addresses the difficult closure of a frozen wall in a coal mine shaft due to excessive seepage velocity in an aquifer when the aquifer is penetrated via the artificial freezing method. Based on hydrothermal coupling theory and considering the effect of decreased absolute porosity on seepage during the freezing process, a mathematical model of hydrothermal full-parameter coupling with a phase change is created. A shaft is used as a prototype, and COMSOL multiphysics finite element software is employed to perform a numerical simulation of the shaft freezing process at various stratum seepage velocities. The numerical simulation results are verified via a comparison with field measurement data. Based on the numerical simulation results, the impact of various underground water seepage velocities on the artificial frozen wall formation process with the seepage-temperature field coupling effect is analysed. Based on the analysis results, the recommended principles of the optimization design for a freezing plan are described as follows: first, the downstream area is closed to enable the water insulation effect, and second, the closure of the upstream area is expedited to reduce the total closure time of a frozen wall.

scholarly journals A numerical study to improve the position and angle of the producer gas injector inside the intake manifold to minimize emissions and efficiency enhancement of a bi engine

2021 ◽  
pp. 100-109
Author(s):  
Hussein A. Mahmood ◽  
Ali O. Al-Sulttani ◽  
Osam H. Attia ◽  
Nor Mariah. Adam
Keyword(s):  
Numerical Simulation ◽  
Numerical Study ◽  
Single Point ◽  
Flow Characteristics ◽  
Engine Performance ◽  
Simulation Software ◽  
Petrol Engine ◽  
Intake Manifold ◽  
Producer Gas ◽  
The Impact

To develop a petrol engine so that it works under the bi-engine pattern (producer gas-petrol) without any additional engine modifications, a single-point injection method inside the intake manifold is a simple and inexpensive method. Still, it leads to poor mixing performance between the air and producer gas. This deficiency can cause unsatisfactory engine performance and high exhaust emissions. In order to improve the mixing inside the intake manifold, nine separate cases were modelled to evaluate the impact of the position and angle orientation inside the intake manifold on the uniformity and spread of the mixture under AFR=2.07. A petrol engine (1.6 L), the maximum engine speed (8000 rpm), and bi-engine mode (petrol-producer gas engine). The employ of the numerical simulation software (ANSYS workbench 19), the propagation, flow characteristics, and uniformity of the blend within the nine different cases were evaluated. According to the outcomes of the numerical simulation, it was found that creating vortices and turbulent flow for the producer gas and air inside the intake manifold is the perfect method to obtain a uniformity mixture of air and producer gas inside the intake manifold. In addition, extending the blending duration allows air and producer gas fuel to be mixed efficiently. Furthermore, the greatest uniformity and the maximum spread rate at the outlet of manifold are obtained in cases 1, 4, and 7, when the producer gas injector location is constant (P1, P2 or P3). In addition, the weakest spread of producer gas at the outlet of the manifold is observed in case 9 in comparison with the other cases. Moreover, it is observed that case (1) generated the maximum uniformity index (UI) level

scholarly journals Electromagnetic Exposure Dosimetry Study on Two Free Rats at 1.8 GHz via Numerical Simulation

2021 ◽  
Vol 9 ◽  
Author(s):  
Xianghui Wang ◽  
Chengjie Xia ◽  
Lu Lu ◽  
Hongxin Qi ◽  
Jie Zhang
Keyword(s):  
Numerical Simulation ◽  
Orientation Angle ◽  
Exposure Dose ◽  
Simulation Software ◽  
Whole Body ◽  
Precise Control ◽  
Variation Rate ◽  
Average Variation ◽  
Processing Techniques ◽  
The Impact

Normally, the impact of electromagnetic exposure on human health is evaluated by animal study. The biological effect caused by electromagnetic exposure on such experimental animals as rats has been proven to be dose-dependent. However, though the dose of radio frequency (RF) electromagnetic exposure described by the specific absorbing rate (SAR) on fixed rats has been relatively well-studied utilizing the numerical simulations, the dosimetry study of exposure on free rat is insufficient, especially in the cases of two or more free rats. Therefore, the present work focuses on the variation of SAR caused by the existence of neighboring free rat in the same cage. Here, infrared thermography was used to record the activity of the two free rats who lived in the same cage that mounted at the far-field region in the microwave darkroom for a duration of 48 h. Then, using image processing techniques, the relative positions and orientations of the two rats are identified, which are defined by three parameters, such as the relative distance (d), relative direction angle (α), and relative orientation angle (β). Using the simulation software XFdtd 7.3, the influence of d, α, and β on the whole-body average SAR (WB-avgSAR) of the rats exposed to 1.8 GHz electromagnetic wave was calculated and analyzed. Then, the average variation of WB-avgSAR of the two rats compared with that of a single rat within 48 h was calculated. The numerical simulation results showed that the relative posture position described by (d, α, and β) of the two rats affects their WB-avgSAR and leads to fluctuations at different positions. However, the variation rate of the 48-h-average WB-avgSAR was only 10.3%, which implied that the over-time average SAR of two or more rats can be roughly described by the WB-avgSAR of a single free rat, except when a real-time precise control of exposure dose is necessary.

scholarly journals Numerical Simulation of Geostress and Support of Roadway Crossing Strata in Complex Stress Condition

2012 ◽  
Vol 446-449 ◽  
pp. 1781-1784
Author(s):  
Tong Xu Wang ◽  
Lai Yuan Li ◽  
Wen Hai Zheng ◽  
Yang Liu ◽  
Tao Hou ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Mining Area ◽  
Complex Stress ◽  
Simulation Software ◽  
Stress Variation ◽  
Roof Structure ◽  
Rock Structure ◽  
Stability Classification ◽  
The Stability ◽  
The Impact

Affected by a group of underground chambers and gobs of working faces, the track sub-inclined shaft of 430 mining area in Geting coal mine, which crosses coal seam and faults repetitively, lies in high and complex stress environment. Based on geostress results measured in the field, FLAC3D numerical simulation software was used to simulate the regional geostress in the area near the roadway, referring to the impact of the gobs and chambers. And the stress variation law along the roadway was given at last. Then the roadway roof structure zone chart was drawn according to the detection results with the rock video detection recorder. Finally, stability of different sections of the roadway and the support advice corresponding to each section was gained. The results show that comprehensive consideration of geostress variation law and surrounding rock structure is necessary in the stability classification and the support of roadways. The research methods and ideas given in this paper is feasible.

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