Basin Tests and Numerical Simulations of Wake-Induced Oscillations of In-Line Risers in Subcritical/Critical Regime

2018 ◽  
Author(s):  
Vincent Levasseur ◽  
Charles Leca ◽  
Benjamin Rousse ◽  
Francois Pétrié
Keyword(s):  
Numerical Simulations ◽  
Industrial Design ◽  
Design Tool ◽  
Critical Regime ◽  
Incoming Flow ◽  
Numerical Approaches

This paper adresses Wake Induced Oscillations in the transition between subcritical and critical regime. Both experimental and numerical approaches are proposed and compared here to model tandem risers motion. The main purpose is to enlarge our insights of the behavior of different arrangements of risers in this very tricky range of incoming flow (Re ∈ [134,000; 300,000]) and to assess the CFD ability as an industrial design tool.

Simulation of multiwavelength conditions in laser picosecond ultrasonics

SIMULATION ◽  
2021 ◽  
pp. 003754972199645
Author(s):  
Philippe Babilotte
Keyword(s):  
Numerical Simulations ◽  
Acoustic Signal ◽  
Acoustic Waves ◽  
Bulk Material ◽  
Deformation Field ◽  
Optical Pump ◽  
Pump And Probe ◽  
Oriented Object ◽  
Numerical Approaches ◽  
Picosecond Ultrasonics

Complete numerical simulations are given under SciLab® and MATLAB® coding environments, concerning propagative acoustic wavefronts, for laser picosecond ultrasonics under multiwavelength conditions. Simulations of the deformation field and its propagation into bulk material are given under different wavelength configurations for optical pump and probe beams, which are used to generate and to detect the acoustic signal. Complete insights concerning the dynamics of the acoustic waves are given, considering the absence of carrier diffusions into the material. Several numerical approaches are proposed concerning both the functions introduced to simulate the wavefront ( Heaviside or error) and the coding approach (linear/vectorized/ Oriented Object Programming), under the pure thermo-elastic approach.

Experiments and Numerical Simulations of Flow Patterns of Water Droplets From Fire-Fighting Helicopters

2000 ◽  
Author(s):  
Kohyu Satoh ◽  
Kohei Sagae ◽  
Kunio Kuwahara ◽  
K. T. Yang
Keyword(s):  
Numerical Simulations ◽  
Forest Fires ◽  
Water Drop ◽  
Real Life ◽  
Large Earthquake ◽  
Flow Patterns ◽  
Design Tool ◽  
Fire Fighting ◽  
Water Application ◽  
Water Droplets

Abstract In large forest fires over wide areas, aerial fire fighting with water drop from helicopters has been widely employed in the world. After the large earthquake fires in Japan, possibilities were raised to employ similar fire-fighting technique to city fires. However, forest and city fires were inherently different in nature and require different fire-fighting implementations. Since the city fires are concentrated in extent and isolated, thus requiring more dense water application to extinguish fires. As a result, accurate engineering data on the optimum water application relative to a given fire are critically needed to design fire-fighting strategies. This study describes the experiments carried out in open fields using real-life helicopters, in comparison with the 3-D numerical simulations. Numerical simulations can provide reasonable flow patterns of the water droplets from the helicopters, and can be used as a design tool for implementing the fire-fighting technique for real city fires.

Minimum Material Design for Propane Cylinder End Closures

2008 ◽  
Vol 130 (1) ◽  
Author(s):  
Y. Kisioglu ◽  
J. R. Brevick ◽  
G. L. Kinzel
Keyword(s):  
Experimental Studies ◽  
Material Design ◽  
Design Tool ◽  
Test Results ◽  
Element Analysis ◽  
Fea Model ◽  
Pressure Tests ◽  
Test Pressure ◽  
Material Nonlinear ◽  
Numerical Approaches

This study addresses the design of DOT-4BA refillable cylinders using both experimental and numerical approaches. Using traditional design methods, these cylinders often experience buckling on the bottom end closure during pressure testing. A finite element analysis (FEA) design tool was developed using axisymmetric material nonlinear conditions to predict the buckling of the cylinder bottom end closures. The FEA model was also used to evaluate the influence of variations in end-closure geometry, material thickness, and strength on buckling. In addition, an optimization algorithm was employed to minimize end-closure material (weight) without buckling when they are subjected to their specified test pressure. Experimental studies were conducted via hydrostatic pressure tests with water at the R&D laboratories of a cylinder manufacturer. The axisymmetric nonlinear FEA models were developed successfully, and the obtained results are compared with experimental test results from cylinder manufacturer case studies.

A PANORAMIC VIEW OF SOME PERTURBED NONLINEAR WAVE EQUATIONS

2004 ◽  
Vol 14 (01) ◽  
pp. 1-40 ◽  
Author(s):  
S. JIMÉNEZ ◽  
P. PASCUAL ◽  
C. AGUIRRE ◽  
L. VÁZQUEZ
Keyword(s):  
Numerical Simulations ◽  
Nonlinear Wave ◽  
Wave Equations ◽  
Nonlinear Wave Equations ◽  
Scalar Wave ◽  
Panoramic View ◽  
Stochastic Perturbations ◽  
Basic Part ◽  
Nonlinear Media ◽  
Numerical Approaches

In this paper we present a panoramic view of numerical simulations associated with nonlinear wave equations which appear in different experimental contexts. Mainly, we deal with scalar wave equations, but also the Maxwell equations in nonlinear media are studied. A basic part of this work is devoted to the construction and verification of numerical schemes on a physical basis. The stochastic perturbations of scalar wave equations are especially analyzed by analytical and numerical approaches. Also, other kinds of perturbations are considered, like nonlocal ones. Finally, a summary of promising experimental results from the numerical simulations of the Maxwell system in a nonlinear media is presented.

scholarly journals Numerical Simulation of the Ducted Propeller and Application to a Semi-Submerged Vehicle

2020 ◽  
Vol 27 (2) ◽  
pp. 19-29
Author(s):  
Jin Zou ◽  
Guoge Tan ◽  
Hanbing Sun ◽  
Jie Xu ◽  
Yongkang Hou
Keyword(s):  
Numerical Simulation ◽  
Numerical Simulations ◽  
Open Water ◽  
The Self ◽  
Hydrodynamic Performance ◽  
Navier Stokes ◽  
Cfd Simulations ◽  
Ducted Propeller ◽  
Numerical Software ◽  
Numerical Approaches

AbstractThe self-propulsion test of underwater vehicles is the key technique for predicting and evaluating the navigation performance of these submersibles. In this study, the numerical simulation of a standard propeller JD7704+Ka4-70 is first presented and the results are compared with experiments to validate the numerical approaches. The reason why the propulsion efficiency of the ducted propeller is higher than that of the conventional propeller is explored. Then, the paper proposes a series of numerical simulations conducted to test the performance of the ducted propeller designed according to the JD7704+Ka4-70 in order to match with the unmanned semi-submerged vehicle (USSV), and the propeller’s open water characteristic curves are obtained. The results show a reasonable agreement with the regression analysis. Afterwards, the numerical simulations focus on a self-propulsion test of the USSV with the designed ducted propeller and the self-propulsion point is obtained. The streamlines through the hull as well as the ducted propellers are clearly obtained, together with the velocity distributions of the propeller plane. The results vividly demonstrate the hydrodynamic performance of the USSV with the designed propellers. In this paper, all the CFD simulations are based on the numerical software, Star-CCM+, and use the Reynolds-averaged Navier‒Stokes (RANS) equations with the shear stress transport (SST) k-omega turbulence model.

scholarly journals STUDY ON DRIFT BEHAVIOR OF CONTAINER ON APRON DUE TO TSUNAMI-INDUCED INCOMING AND RETURN FLOW

2012 ◽  
Vol 1 (33) ◽  
pp. 16 ◽  
Author(s):  
Tomoaki Nakamura ◽  
Norimi Mizutani ◽  
Yasuhiro Wakamatsu
Keyword(s):  
Numerical Simulations ◽  
Initial Position ◽  
Numerical Results ◽  
Return Flow ◽  
Incoming Flow ◽  
Shipping Container ◽  
Quay Wall ◽  
The Cross ◽  
Drift Behavior

The drift behavior of a shipping container on an apron resulting from a tsunami-induced incoming flow and subsequent return flow is investigated using hydraulic experiments and numerical simulations. Experimental and numerical results show that the container initially set parallel to a quay wall can fall into the sea when the relative overflow height of an incident tsunami is large regardless of the relative initial position of the container. This suggests that it is not always effective to shelter containers near the seawall before large tsunamis. In addition, it is not evident that the container initially set perpendicular to the quay wall drifts seaward, suggesting that an effective countermeasure would be to store containers on the apron in the cross-shore direction.

scholarly journals Introducing Virtual Reality Technologies to Design Education

Seminar.net ◽  
2018 ◽  
Vol 14 (1) ◽  
pp. 1-12
Author(s):  
Jonna Häkkilä ◽  
Ashley Colley ◽  
Jani Väyrynen ◽  
Antti-Jussi Yliharju
Keyword(s):  
Virtual Reality ◽  
Design Education ◽  
Industrial Design ◽  
3D Models ◽  
Design Tool ◽  
Point Of View ◽  
Head Mounted Display ◽  
Teaching Point ◽  
User Groups ◽  
Set Up

In this paper, we address the introduction of Virtual Reality (VR) tools to the education of industrial design (ID) university students. We present three cases of how we have introduced VR technology in different courses of the industrial design curriculum at the University of Lapland, Finland. As the first example (Case I), we introduced a VR simulation as an empathetic design tool to simulate visual disabilities. The second example (Case II) is reported from a course where students created concepts for a head mounted display (HMD) AR application in smart buildings, and tried out interaction with a HMD VR application. In the third example (Case III), VR was used as a display environment to exhibit students’ 3D industrial design concept models. We report our experiences and lessons learnt, as well as recorded student feedback from the trials. As salient findings, we report the general positive feedback, successful integration with the taught themes especially when connected to physical 3D models, as well as suggested improvements. Hindering the adoption of the technology from the teaching point of view, we report on the lack of infrastructure for multi-user groups in classrooms, the additional effort required to set up the technical system, and limited features supporting multimodality.

Effective Mockup Utilization by the Industrial Design—Human Factors Team

1966 ◽  
Vol 8 (4) ◽  
pp. 347-359 ◽  
Author(s):  
Joseph L. Seminara ◽  
James K. Gerrie
Keyword(s):  
Human Factors ◽  
Industrial Design ◽  
System Development ◽  
Effective Means ◽  
Three Dimensional ◽  
Design Tool ◽  
Design Development ◽  
Aerospace Systems ◽  
Support Team ◽  
Advanced System

Mockup technology, the transformation of two-dimensional design drawings into three-dimensional representations of hardware concepts, is a well established design tool within the engineering community. When employed or controlled by the industrial design-human factors support team, mockup development is an extremely effective means for influencing equipment design so that the needs of the eventual user are served. A number of difficulties that confront the industrial designer within the aerospace industry setting are discussed. One method of entering into the advanced system development process is through the assumption of responsibility for mockup design, development, construction and evaluation. In the course of mockup development, excellent opportunities are available for introducing human factors and industrial design principles into preliminary and detailed design of advanced manned systems. The diverse purposes served by mockups are discussed, and representative case histories illustrating the application of various mockup techniques in aerospace systems are presented.

scholarly journals Analysis of the localization process leading to fragmentation of dynamically expanded rings

2018 ◽  
Vol 183 ◽  
pp. 01064
Author(s):  
Skander El Maï ◽  
Sébastien Mercier ◽  
Alain Molinari
Keyword(s):  
Stability Analysis ◽  
Power Spectrum ◽  
Numerical Simulations ◽  
Linear Stability Analysis ◽  
Statistical Approach ◽  
History Of Development ◽  
Round Bar ◽  
History Of ◽  
Good Agreement ◽  
Numerical Approaches

A novel extension of the Linear Stability Analysis (LSA) applied to the development of the instabilities in a round bar in dynamic extension is proposed. The history of development of the instabilities and the multi-modal aspect of the perturbations are now considered in this extension. A new statistical approach based on the power spectrum of the perturbation pattern is proposed to evaluate the variability of the spacing between potential sites of necking. This approach has been applied to analyze the LSA results and predictions obtained from numerical simulations of a bar in dynamic extension. It is shown that both analytical and numerical approaches provides good agreement

scholarly journals Modeling of Coaxial Slot Waveguides Using Analytical and Numerical Approaches: Revisited

2012 ◽  
Vol 2012 ◽  
pp. 1-12
Author(s):  
Kok Yeow You ◽  
Jamaliah Salleh ◽  
Mohd Fareq Abd Malek ◽  
Zulkifly Abbas ◽  
Cheng Ee Meng ◽  
...  
Keyword(s):  
Numerical Methods ◽  
Numerical Simulations ◽  
Frequency Domain ◽  
Analytical Methods ◽  
Fringing Field ◽  
Coaxial Waveguides ◽  
Physical Principles ◽  
Numerical Approaches ◽  
Slot Waveguides

Our reviews of analytical methods and numerical methods for coaxial slot waveguides are presented. The theories, background, and physical principles related to frequency-domain electromagnetic equations for coaxial waveguides are reassessed. Comparisons of the accuracies of various types of admittance and impedance equations and numerical simulations are made, and the fringing field at the aperture sensor, which is represented by the lumped capacitance circuit, is evaluated. The accuracy and limitations of the analytical equations are explained in detail. The reasons for the replacement of analytical methods by numerical methods are outlined.

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