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.

Using Ansys for Design and Numerical Study of a Specific Fixed Wing UAV

2018 ◽  
Vol 55 (4) ◽  
pp. 652-657 ◽  
Author(s):  
Gabriel Murariu ◽  
Razvan Adrian Mahu ◽  
Adrian Gabriel Murariu ◽  
Mihai Daniel Dragu ◽  
Lucian P. Georgescu ◽  
...  
Keyword(s):  
Numerical Simulations ◽  
Unmanned Aerial Vehicle ◽  
Numerical Study ◽  
Flight Time ◽  
Cluster System ◽  
Numerical Results ◽  
Operational Performance ◽  
Gliding Flight ◽  
Aerial Vehicle ◽  
Constant Altitude

This article presents the design of a specific unmanned aerial vehicle UAV prototype own building. Our UAV is a flying wing type and is able to take off with a little boost. This system happily combines some major advantages taken from planes namely the ability to fly horizontal, at a constant altitude and of course, the great advantage of a long flight-time. The aerodynamic models presented in this paper are optimized to improve the operational performance of this aerial vehicle, especially in terms of stability and the possibility of a long gliding flight-time. Both aspects are very important for the increasing of the goals� efficiency and for the getting work jobs. The presented simulations were obtained using ANSYS 13 installed on our university� cluster system. In a next step the numerical results will be compared with those during experimental flights. This paper presents the main results obtained from numerical simulations and the obtained magnitudes of the main flight coefficients.

Experimental and numerical investigations on a high-density polyethylene (HDPE) blown film cooling with a new design of the counter-flow/radial jet air-ring

2021 ◽  
pp. 875608792110260
Author(s):  
ME Ismail ◽  
MM Awad ◽  
AM Hamed ◽  
MY Abdelaal ◽  
EB Zeidan
Keyword(s):  
Heat Transfer ◽  
Numerical Simulations ◽  
Film Cooling ◽  
Radiation Heat Transfer ◽  
Absolute Error ◽  
Numerical Results ◽  
Upper Lip ◽  
Original Design ◽  
Blown Film ◽  
Set Up

This study experimentally and numerically investigates a typical HDPE blown film production process cooled via a single-lip air-ring. The processing observations are considered for the proposed subsequent modifications on the air-ring design and the location relative to the die to generate a radial jet, directly impinging on the bubble. Measurements are performed to collect the actual operating parameters to set up the numerical simulations. The radiation heat transfer and the polymer phase change are considered in the numerical simulations. The velocity profile at the air-ring upper-lip is measured via a five-hole Pitot tube to compare with the numerical results. The comparison between the measurements and the numerical results showed that the simulations with the STD [Formula: see text] turbulence model are more accurate with a minimum relative absolute error (RAE) of 1.6%. The numerical results indicate that the peak Heat Transfer Coefficient (HTC) at the impingement point for the modified design with radial jet and longer upper-lip is 29.1% higher than the original design at the same conditions. Besides, increasing the air-ring upper-lip height increased the averaged HTC, which is 13.4% higher than the original design.

Numerical simulation of squeezing Cu–Water nanofluid flow by a kernel-based method

2021 ◽  
pp. 2250005
Author(s):  
Mojtaba Fardi ◽  
Yasir Khan
Keyword(s):  
Numerical Simulation ◽  
Hilbert Space ◽  
Linear System ◽  
Numerical Simulations ◽  
Numerical Results ◽  
Kernel Matrix ◽  
Nanofluid Flow ◽  
Parallel Disks ◽  
Engineering Problems ◽  
Well Conditioning

The main aim of this paper is to propose a kernel-based method for solving the problem of squeezing Cu–Water nanofluid flow between parallel disks. Our method is based on Gaussian Hilbert–Schmidt SVD (HS-SVD), which gives an alternate basis for the data-dependent subspace of “native” Hilbert space without ever forming kernel matrix. The well-conditioning linear system is one of the critical advantages of using the alternate basis obtained from HS-SVD. Numerical simulations are performed to illustrate the efficiency and applicability of the proposed method in the sense of accuracy. Numerical results obtained by the proposed method are assessed by comparing available results in references. The results demonstrate that the proposed method can be recommended as a good option to study the squeezing nanofluid flow in engineering problems.

scholarly journals Numerical Modeling of Flow Over a Rectangular Broad-Crested Weir with a Sloped Upstream Face

Water ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1663 ◽  
Author(s):  
Lei Jiang ◽  
Mingjun Diao ◽  
Haomiao Sun ◽  
Yu Ren
Keyword(s):  
Numerical Simulations ◽  
Discharge Coefficient ◽  
Separation Zone ◽  
Turbulence Models ◽  
Numerical Results ◽  
Upstream Face ◽  
Flow Conditions ◽  
Flow Features ◽  
The Mean ◽  
Absolute Percent Error

The objective of this study was to evaluate the effect of the upstream angle on flow over a trapezoidal broad-crested weir based on numerical simulations using the open-source toolbox OpenFOAM. Eight trapezoidal broad-crested weir configurations with different upstream face angles (θ = 10°, 15°, 22.5°, 30°, 45°, 60°, 75°, 90°) were investigated under free-flow conditions. The volume-of-fluid (VOF) method and two turbulence models (the standard k-ε model and the SST k-w model) were employed in the numerical simulations. The numerical results were compared with the experimental results obtained from published papers. The root mean square error (RMSE) and the mean absolute percent error (MAPE) were used to evaluate the accuracy of the numerical results. The statistical results show that RMSE and MAPE values of the standard k-ε model are 0.35–0.67% and 0.50–1.48%, respectively; the RMSE and MAPE values of the SST k-w model are 0.25–0.66% and 0.55–1.41%, respectively. Additionally, the effects of the upstream face angle on the flow features, including the discharge coefficient and the flow separation zone, were also discussed in the present study.

scholarly journals Discussion on the Theoretical Basis for Cross-Over Method Applied to Downhole Wave Velocity Test

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Qing Dong ◽  
Zheng-hua Zhou ◽  
Su Jie ◽  
Bing Hao ◽  
Yuan-dong Li
Keyword(s):  
Numerical Simulation ◽  
Numerical Simulations ◽  
Wave Velocity ◽  
Theoretical Basis ◽  
Influence Factors ◽  
P Wave ◽  
Engineering Practice ◽  
S Wave ◽  
Simulation Results ◽  
The Cross

At engineering practice, the theoretical basis for the cross-over method, used to obtain shear wave arrival time in the downhole method of the wave velocity test by surface forward and backward strike, is that the polarity of P-wave keeps the same, while the polarity of S-wave transforms when the direction of strike inverted. However, the characteristics of signals recorded in tests are often found to conflict with this theoretical basis for the cross-over method, namely, the polarity of the P-wave also transforms under the action of surface forward and backward strike. Therefore, 3D finite element numerical simulations were conducted to study the validity of the theoretical basis for the cross-over method. The results show that both shear and compression waves are observed to be in 180° phase difference between horizontal signal traces, consistent with the direction of excitation generated by reversed impulse. Furthermore, numerical simulation results prove to be reliable by the analytic solution; it shows that the theoretical basis for the cross-over method applied to the downhole wave velocity test is improper. In meanwhile, numerical simulations reveal the factors (inclining excitation, geophone deflection, inclination, and background noise) that may cause the polarity of the P-wave not to reverse under surface forward and backward strike. Then, as to reduce the influence factors, we propose a method for the downhole wave velocity test under surface strike, the time difference of arrival is based between source peak and response peak, and numerical simulation results show that the S-wave velocity by this method is close to the theoretical S-wave velocity of soil.

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.

Numerical Performance of Thermodynamic Behavior of Shipping-Container Architecture

Proceedings ◽  
2019 ◽  
Vol 44 (1) ◽  
pp. 9
Author(s):  
Ivan Felis Enguix ◽  
Jorge Otero Vega ◽  
Sina Ellesser
Keyword(s):  
Numerical Simulations ◽  
Thermal Inertia ◽  
Thermodynamic Behavior ◽  
Shipping Container ◽  
Design Resources ◽  
Shipping Containers ◽  
Numerical Performance ◽  
Different Climates

The reuse of shipping containers in architecture has grown in global popularity. However, few studies focus on understanding its thermodynamic behavior. The present study addresses, through numerical simulations, the transitory behavior of a typical house built with containers under different climates, both cold and warm. We examined container with different build construction and observed their effect, from completely naked to those that are coated with materials of different insulation and thermal inertia. Additionally, orientation and other design resources, such as height with respect to the ground, shadow elements, and the position of the windows, were considered. With all these multiparametric studies, quantitative conclusions were obtained that can be considered in design.

scholarly journals A robotic crawler exploiting directional frictional interactions: experiments, numerics and derivation of a reduced model

2014 ◽  
Vol 470 (2171) ◽  
pp. 20140333 ◽  
Author(s):  
Giovanni Noselli ◽  
Antonio DeSimone
Keyword(s):  
Numerical Simulations ◽  
Solid Substrate ◽  
Numerical Results ◽  
Reduced Model ◽  
Shape Changes

We present experimental and numerical results for a model crawler which is able to extract net positional changes from reciprocal shape changes, i.e. ‘breathing-like’ deformations, thanks to directional, frictional interactions with a textured solid substrate, mediated by flexible inclined feet. We also present a simple reduced model that captures the essential features of the kinematics and energetics of the gait, and compare its predictions with the results from experiments and from numerical simulations.

Flow Characteristics of Rarified Gases in Micro-Grooved Channels by the Lattice-Boltzmann Method

2008 ◽  
Author(s):  
Amador M. Guzma´n ◽  
Andre´s J. Di´az ◽  
Luis E. Sanhueza ◽  
Rodrigo A. Escobar
Keyword(s):  
Numerical Simulations ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Pressure Ratio ◽  
Plane Channel ◽  
Flow Characteristics ◽  
Numerical Results ◽  
Knudsen Numbers ◽  
Channel Configuration ◽  
Boltzmann Method

The flow characteristics of a rarified gas have been investigated in microgrooved channels. The governing Boltzmann Transport Equation (BTE) is solved by the Lattice-Boltzmann method (LBM) for the Knudsen number range of 0.01–0.1. First, the compressibility and rarified effects are investigated in a plane channel by performing numerical simulations for different Knudsen numbers, pressure ratio and accommodation coefficients with the objective of validating the computational code used in this investigation and determining the transition characteristics from the macro to microscale. The numerical predictions are compared to existing analytical and numerical results. Then, numerical simulations are performed for microgrooved channels for the Knudsen numbers range of [0.01–0.1]. Different meshes are used for preserving numerical stabilities and obtaining accurate enough numerical results. For the microgrooved channel configuration, the fluid characteristics are determined in terms of pressure ratio and Knudsen numbers. The numerical results are compared to existing analytical predictions and numerical results obtained from plane channel and one cavity simulations.

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