A Three-Dimensional Model for Strength Assessment of Type-C Independent Cargo Tank Structures

2020 ◽  
Vol 36 (04) ◽  
pp. 271-279
Author(s):  
Ming Song ◽  
Bin Qin ◽  
Li Zhou ◽  
Zhengru Ren
Keyword(s):  
Three Dimensional ◽  
Liquefied Petroleum Gas ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Strength Assessment ◽  
One Dimensional ◽  
Proposed Model ◽  
Linear Spring ◽  
Type C ◽  
Three Dimensional Models

For the analysis of the arrangement and strength of Type-C independent cargo tank structures, the linear spring or rod elements are usually used to model supporting woods, in which one-dimensional and linear contact behaviors are assumed. This study aimed at developing a three-dimensional model for achieving more accurate strength assessment. In the model, solid elements are modeled to simulate the supporting woods. The nonlinear contact between the cargo tanks and the supporting woods is taken into account through LS-DYNA software. Numerical simulations of a 22,000-m3 liquefied petroleum gas carrier are carried out using both one-dimensional and three-dimensional models. Three load cases including one static and two dynamic cases are considered to assess the strength of the tank structures and supporting woods. The results obtained by the proposed model are compared with the results on the basis of spring elements. It is found that this new model can provide more reasonable strength predictions of the tank structures and the supporting woods. The method based on spring elements underestimates the wood stress, which indicates that it may be not conservative. Some discussions and suggestions are presented.

Modeling the temperature shock of elastic elements using a one-dimensional model of thermal conductivity

2020 ◽  
pp. 2050060
Author(s):  
D. A. Belousova ◽  
V. V. Serdakova
Keyword(s):  
Thermal Conductivity ◽  
Three Dimensional ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Temperature Shock ◽  
One Dimensional ◽  
Small Spacecraft ◽  
Proposed Model ◽  
Direct Approximation ◽  
Elastic Elements

This paper considers the task of evaluating micro-accelerations arising due to the temperature shock of large elastic elements when a small spacecraft leaves the Earth’s shadow. In this case, a one-dimensional model of thermal conductivity is used. Its solution was obtained by the method of direct approximation with the construction of difference schemes. It is shown that the accuracy of estimating micro-accelerations is commensurate with the accuracy of solving by a three-dimensional model of thermal conductivity. The proposed model allows reducing the time to obtain estimates and significantly simplifies the task at hand. The results of the work can be used in the formation of the dynamic characteristics of a small spacecraft for technological purposes.

On the numerical study of thermohydrodynamics and biochemistry of inland water bodies

2021 ◽  
Author(s):  
Daria Gladskikh ◽  
Evgeny Mortikov ◽  
Victor Stepanenko
Keyword(s):  
Mixed Layer ◽  
Numerical Study ◽  
Three Dimensional ◽  
Water Bodies ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
One Dimensional ◽  
Lake Model ◽  
Upper Mixed Layer ◽  
The One

<p>The study of thermodynamic and biochemical processes of inland water objects using one- and three-dimensional RANS numerical models was carried out both for idealized water bodies and using measurements data. The need to take into account seiche oscillations to correctly reproduce the deepening of the upper mixed layer in one-dimensional (vertical) models is demonstrated. We considered the one-dimensional LAKE model [1] and the three-dimensional model [2, 3, 4] developed at the Research Computing Center of Moscow State University on the basis of a hydrodynamic code combining DNS/LES/RANS approaches for calculating geophysical turbulent flows. The three-dimensional model was supplemented by the equations for calculating biochemical substances by analogy with the one-dimensional biochemistry equations used in the LAKE model. The effect of mixing processes on the distribution of concentration of greenhouse gases, in particular, methane and oxygen, was studied.</p><p>The work was supported by grants of the RF President’s Grant for Young Scientists (MK-1867.2020.5, MD-1850.2020.5) and by the RFBR (19-05-00249, 20-05-00776). </p><p>1. Stepanenko V., Mammarella I., Ojala A., Miettinen H., Lykosov V., Timo V. LAKE 2.0: a model for temperature, methane, carbon dioxide and oxygen dynamics in lakes // Geoscientific Model Development. 2016. V. 9(5). P. 1977–2006.<br>2. Mortikov E.V., Glazunov A.V., Lykosov V.N. Numerical study of plane Couette flow: turbulence statistics and the structure of pressure-strain correlations // Russian Journal of Numerical Analysis and Mathematical Modelling. 2019. 34(2). P. 119-132.<br>3. Mortikov, E.V. Numerical simulation of the motion of an ice keel in stratified flow // Izv. Atmos. Ocean. Phys. 2016. V. 52. P. 108-115.<br>4. Gladskikh D.S., Stepanenko V.M., Mortikov E.V. On the influence of the horizontal dimensions of inland waters on the thickness of the upper mixed layer // Water Resourses. 2021.V. 45, 9 pages. (in press) </p>

scholarly journals Hydraulic modeling of combined sewers overflow integrating the results of the SWMM and CFX models.

2021 ◽  
Vol 37 (1) ◽  
Author(s):  
D. Pulgarín ◽  
J. Plaza ◽  
J. Ruge ◽  
J. Rojas
Keyword(s):  
Three Dimensional ◽  
Hydraulic Modeling ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
One Dimensional ◽  
Ansys Cfx ◽  
Combined Sewer ◽  
The One ◽  
Swmm Model

This study proposes a methodology for the calibration of combined sewer overflow (CSO), incorporating the results of the three-dimensional ANSYS CFX model in the SWMM one-dimensional model. The procedure consists of constructing calibration curves in ANSYS CFX that relate the input flow to the CSO with the overflow, to then incorporate them into the SWMM model. The results obtained show that the behavior of the flow over the crest of the overflow weir varies in space and time. Therefore, the flow of entry to the CSO and the flow of excesses maintain a non-linear relationship, contrary to the results obtained in the one-dimensional model. However, the uncertainty associated with the idealization of flow methodologies in one dimension is reduced under the SWMM model with kinematic wave conditions and simulating CSO from curves obtained in ANSYS CFX. The result obtained facilitates the calibration of combined sewer networks for permanent or non-permanent flow conditions, by means of the construction of curves in a three-dimensional model, especially when the information collected in situ is limited.

Three-Dimensional Model of the Human Eye-Head Saccadic System

1997 ◽  
Vol 77 (2) ◽  
pp. 654-666 ◽  
Author(s):  
Douglas Tweed
Keyword(s):  
Three Dimensional ◽  
Head Movements ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Gaze Shifts ◽  
One Dimensional ◽  
Human Eye ◽  
Saccadic System ◽  
Listing's Law ◽  
Listing’S Law

Tweed, Douglas. Three-dimensional model of the human eye-head saccadic system. J. Neurophysiol. 77: 654–666, 1997. Current theories of eye-head gaze shifts deal only with one-dimensional motion, and do not touch on three-dimensional (3-D) issues such as curvature and Donders' laws. I show that recent 3-D data can be explained by a model based on ideas that are well established from one-dimensional studies, with just one new assumption: that the eye is driven toward a 3-D orientation in space that has been chosen so that Listing's law of the eye in head will hold when the eye-head movement is complete. As in previous, one-dimensional models, the eye and head are feedback-guided and the commands specifying desired eye position eye pass through a neural “saturation” so as to stay within the effective oculomotor range. The model correctly predicts the complex, 3-D trajectories of the head, eye in space, and eye in head in a variety of saccade tasks. And when it moves repeatedly to the same target, varying the contributions of eye and head, the model lands in different eye-in-space positions, but these positions differ only in their cyclotorsion about the line of sight, so they all point that line at the target—a behavior also seen in real eye-head saccades. Between movements the model obeys Listing's law of the eye in head and Donders' law of the head on torso, but during certain gaze shifts involving large torsional head movements, it shows marked, 8° deviations from Listing's law. These deviations are the most important untested predictions of the theory. Their experimental refutation would sink the model, whereas confirmation would strongly support its central claim that the eye moves toward a 3-D position in space chosen to obey Listing's law and, therefore, that a Listing operator exists upstream from the eye pulse generator.

scholarly journals Methods building and printing 3D models historical architectural objects

2020 ◽  
Vol 75 ◽  
pp. 04016 ◽  
Author(s):  
Ihor Hevko ◽  
Olha Potapchuk ◽  
Iryna Lutsyk ◽  
Viktorya Yavorska ◽  
Viktoriia Tkachuk
Keyword(s):  
3D Printing ◽  
Complex Systems ◽  
Three Dimensional ◽  
3D Models ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Specialized Software ◽  
Bulk Data ◽  
Three Dimensional Models ◽  
Accuracy Speed

The authors present methods building and printing three-dimensional models for graphical reconstruction of historical architectural objects. Procedure sequence of the methods is exemplified through building the model of the Parochial Cathedral of St. Mary of the Perpetual Assistance of the 1950s. After analyzing and assessing the most popular specialized software means, the 3DS Max environment is chosen to build a three-dimensional model. Suggested software tools enable increased accuracy, speed and granularity of fixation of complex systems and expanded databases, providing efficient instruments to deal with bulk data and being relevant to new IT achievements. Sequence and content of operations for analytical and modeling cycles are substantiated. The cathedral model is built on the basis of archive photographs and drafts. The authors describe methods and the algorithm of procedures, principles of architectural and spacious modeling to recreate the architectural object. The three-dimensional model is built by applying a stereogram miniature of the destroyed Cathedral. Reconstruction of spacious configuration of the objects is based on parallax assessment of images. Stages of project implementation are determined. There are described methods of implementing modeling by 3DS Max tools and preparing the model for 3D printing in Cura.

Design of Above-Knee Prosthesis: A Finite Element Stress Analysis

2015 ◽  
Vol 1125 ◽  
pp. 432-436 ◽  
Author(s):  
Sandro Mihradi ◽  
Calvindoro Zeus Abdiwijaya ◽  
Tatacipta Dirgantara ◽  
Andi Isra Mahyuddin
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Knee Prosthesis ◽  
Three Dimensional ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Strength Criteria ◽  
Finite Element Stress Analysis ◽  
Three Dimensional Models ◽  
Four Bar Linkage

In the present research, three-dimensional models of above-knee prosthesis, consist of socket, four-bar linkage knee, pylon and foot, are developed. These models have to fulfill criteria such as stability, ability to withstand up to 90 kg of bodyweight, ability to flex up to 130 degree, easy for maintenance, simple manufacturing process, affordable and yet reliable. As the first step of development, these models were evaluated using finite element method software to determine whether or not the design has fulfilled strength criteria. The results show that the last iteration of the three dimensional model of the knee prosthesis has satisfied the criteria.

On the modeling of thermohydrodynamic and biogeochemical processes in the inland water objects

2020 ◽  
Author(s):  
Daria Gladskikh ◽  
Evgeny Mortikov ◽  
Victor Stepanenko
Keyword(s):  
Carbon Dioxide ◽  
Numerical Study ◽  
Three Dimensional ◽  
Measurement Data ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Inland Water ◽  
One Dimensional ◽  
Biochemical Processes ◽  
Dimensional Models

<p>Currently, one-dimensional and three-dimensional models are widely used to model thermohydrodynamic and biochemical processes in lakes and water rеreservoirs. One-dimensional models are highly computationally efficient and are used to parameterize land water bodies in climate models, however, when calculating large lakes and reservoirs with complex geometry, such models may incorrectly reproduce processes associated with horizontal heterogeneity. This becomes especially important for the prediction of water quality and euthrophication.</p><p>A three-dimensional model of thermohydrodynamics and biochemistry of an inland water obect is presented, which is based on the hydrostatic RANS model [1-3], and the parameterization of biochemical processes is implemented by analogy with the scheme for calculating biochemistry in the one-dimensional LAKE model [4]. Thus, the three-dimensional model is supplemented by a description of the transport of substances such as oxygen (O<sub>2</sub>), carbon dioxide (CO<sub>2</sub>), methane (CH<sub>4</sub>), as well as phyto- and zooplankton. The effect of turbulent diffusion and large-scale water movements on the distribution of a methane concentration field is studied.</p><p>To verify the calculation results, idealized numerical experiments and comparison with the measurement data on Lake Kuivajärvi (Finland) were used.</p><p>The work was supported by grants of the RF President’s Grant for Young Scientists (MK-1867.2020.5, MD-1850.2020.5) and by the RFBR (18-05-00292, 18-35-00602, 20-05-00776). <br><br>References:<br>[1] Mortikov E.V. Numerical simulation of the motion of an ice keel in stratified flow // Izv. Atmos. Ocean. Phys. 2016. 52. P. 108-115.<br>[2] Mortikov E.V., Glazunov A.V., Lykosov V.N. Numerical study of plane Couette flow: turbulence statistics and the structure of pressure-strain correlations // Russian Journal of Numerical Analysis and Mathematical Modelling. 2019. V. 34, N 2. P. 119-132.<br>[3] D.S. Gladskikh, V.M. Stepanenko, E.V. Mortikov, On the influence of the horizontal dimensions of inland waters on the thickness of the upper mixed layer. // Water Resourses. 2019. 18 pages. (submitted)<br>[4] Victor Stepanenko, Ivan Mammarella, Anne Ojala, Heli Miettinen, Vasily Lykosov, and Vesala Timo. LAKE 2.0: a model for temperature, methane, carbon dioxide and oxygen dynamics in lakes. Geoscientific Model Development, 9(5): 1977–2006, 2016.</p>

Study on the Application of Computer Three-Dimensional Model's Simulation Functions

2013 ◽  
Vol 443 ◽  
pp. 27-30
Author(s):  
Qin Gu
Keyword(s):  
Three Dimensional ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Simulation Functions ◽  
Dimensional Models ◽  
Three Dimensional Models

In this paper, the simulation functions of computer three-dimensional model as well as the advantages in the simulated application are briefly introduced, and also the application of the three-dimensional models simulation functions to the different industries is discussed in details.

scholarly journals COORDINATE SYSTEM FOR REPRESENTATION OF MULTIDIMENSIONAL DATA

2018 ◽  
pp. 40-44
Author(s):  
A. B. Lachikhina ◽  
K. N. Soldatov
Keyword(s):  
Three Dimensional ◽  
Data Representation ◽  
Three Dimensions ◽  
Multidimensional Data ◽  
Independent Data ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Proposed Model ◽  
Multidimensional Array ◽  
Number Of Faces

Visualization of analyzing multidimensional data is often required in order to improve perception and visibility. The purpose of this research is a multidimensional array of data representation. It is proposed to use a three-dimensional model as a tool. The methods used to represent an array of data with more than three dimensions are presented. The principle of constructing a multidimensional array cell is considered. An example of the constructed hypercube cell is given. The formulas for calculating the number of faces of the figure, the number of triangles that can be built through points, the number of internal triangles are obtained. The approach of visualization of aggregates is described. The use of color gradation to improve the convenience of perception of the cell in the analysis of the cube cells. It is concluded that the proposed model allows us to perceive each cell as an independent data element in the construction of charts for the analyzed indicators.

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