Numerical Simulation of Water Impact of 2D Wedge with Different Density

2014 ◽  
Vol 623 ◽  
pp. 73-77
Author(s):  
Cheng Jun Li ◽  
Hui Long Ren ◽  
Chen Feng Li
Keyword(s):  
Numerical Simulation ◽  
Free Surface ◽  
Linear Problem ◽  
Water Impact ◽  
Numerical Result ◽  
Non Linear

It remains unresolved to study the relation between the density of wedge and its impact. Fluent is applied to simulate its mechanism with 6DOF model. After the comparison of numerical result and the theoretical, it matches good and then the transient free surface scene is observed. Thus Fluent is able to solve this kind of non-linear problem. And the effect of density of wedge on the slamming character is also studied.

On the Non-Linear Decay Motion of an Oscillatory Plate

2005 ◽  
Author(s):  
K. Abdolmaleki ◽  
K. P. Thiagarajan ◽  
J. J. Monaghan
Keyword(s):  
Free Surface ◽  
Water Jet ◽  
The Body ◽  
Green Water ◽  
Water Impact ◽  
Non Linear ◽  
Run Up ◽  
The Impact ◽  
System Characteristics ◽  
Linear Decay

We study the non-linear decay motion of a 2D plate experimentally and analytically. The plate was hinged to the bottom of a wave flume and was positioned at a certain initial angle. The restoring force on the plate was derived from two horizontal pre-tensioned springs. To maintain the system characteristics linear, the springs were selected to allow a maximum 18 degrees of rotation for the plate. The position, velocity and the acceleration of the plate were retrieved from the load cells attached to the springs. The plate was released from its initial position at t = 0 and allowed to oscillate. The free-surface elevation was captured using a high frame per second (200 fps) digital camera. In addition, two wave probes on either side of the plate were installed. It was observed that the high stiffness of the springs produced a mild impact to the water that caused a relatively large water run-up and water jet. This event, consequently, made the decay motion very non-linear. A formulation based on the linear theory was developed to help with the understanding and interpreting the physics of the problem. The presented experiment aims to benchmark various numerical techniques such as Smoothed Particle Hydrodynamics (SPH) that intend to simulate free-surface and water impact problems. Although the setup did not model a green water incident, most of the features in the problem, like initial water impact, run up and water jet resemble the physics of green water. In the designed experiment, not only body 3D effects were minimum, but also the system characteristics were linear. Moreover, in contrast to the dam break experiments, perfect initial conditions were achieved. Therefore, the effects of the flow nonlinearities such as the plate impact to the water, water run up-down and water jet were studied without interference of the body nonlinearities. The impact of these effects on the damping and the added mass were highlighted.

scholarly journals Numerical simulation of the oscillations of non-newtonian viscous fluids with a free surface

2000 ◽  
Vol 4 (2) ◽  
pp. 111-123
Author(s):  
A. Korobeinikov
Keyword(s):  
Numerical Simulation ◽  
Free Surface ◽  
Numerical Simulations ◽  
Numerical Method ◽  
Newtonian Fluids ◽  
Viscous Fluids ◽  
Bingham Fluids ◽  
Small Oscillations ◽  
Non Linear

Non-Newtonian fluids are increasingly being transported by a variety of vehicles. It has been observed that vehicles containing such fluids demonstrate behaviour which could be explained only by non-linearity characteristics of such fluids. In this paper small oscillations of non-Newtonian fluids in tanks are considered. A numerical method suitable for both Newtonian and non-Newtonian fluids is suggested. Examples of numerical simulations with emphasis on Bingham fluids are given to demonstrate effects of non-linear properties.

scholarly journals Assessment of Extrapolation Relations of Displacement Speed for Detailed Chemistry Direct Numerical Simulation Database of Statistically Planar Turbulent Premixed Flames

2021 ◽  
Author(s):  
Nilanjan Chakraborty ◽  
Alexander Herbert ◽  
Umair Ahmed ◽  
Hong G. Im ◽  
Markus Klein
Keyword(s):  
Numerical Simulation ◽  
Direct Numerical Simulation ◽  
Premixed Flames ◽  
Turbulent Premixed Flames ◽  
Reaction Progress ◽  
Progress Variable ◽  
Stretch Rate ◽  
Non Linear ◽  
Displacement Speed ◽  
Curvature Dependence

AbstractA three-dimensional Direct Numerical Simulation (DNS) database of statistically planar $$H_{2} -$$ H 2 - air turbulent premixed flames with an equivalence ratio of 0.7 spanning a large range of Karlovitz number has been utilised to assess the performances of the extrapolation relations, which approximate the stretch rate and curvature dependences of density-weighted displacement speed $$S_{d}^{*}$$ S d ∗ . It has been found that the correlation between $$S_{d}^{*}$$ S d ∗ and curvature remains negative and a significantly non-linear interrelation between $$S_{d}^{*}$$ S d ∗ and stretch rate has been observed for all cases considered here. Thus, an extrapolation relation, which assumes a linear stretch rate dependence of density-weighted displacement speed has been found to be inadequate. However, an alternative extrapolation relation, which assumes a linear curvature dependence of $$S_{d}^{*}$$ S d ∗ but allows for a non-linear stretch rate dependence of $$S_{d}^{*}$$ S d ∗ , has been found to be more successful in capturing local behaviour of the density-weighted displacement speed. The extrapolation relations, which express $$S_{d}^{*}$$ S d ∗ as non-linear functions of either curvature or stretch rate, have been found to capture qualitatively the non-linear curvature and stretch rate dependences of $$S_{d}^{*}$$ S d ∗ more satisfactorily than the linear extrapolation relations. However, the improvement comes at the cost of additional tuning parameter. The Markstein lengths LM for all the extrapolation relations show dependence on the choice of reaction progress variable definition and for some extrapolation relations LM also varies with the value of reaction progress variable. The predictions of an extrapolation relation which involve solving a non-linear equation in terms of stretch rate have been found to be sensitive to the initial guess value, whereas a high order polynomial-based extrapolation relation may lead to overshoots and undershoots. Thus, a recently proposed extrapolation relation based on the analysis of simple chemistry DNS data, which explicitly accounts for the non-linear curvature dependence of the combined reaction and normal diffusion components of $$S_{d}^{*}$$ S d ∗ , has been shown to exhibit promising predictions of $$S_{d}^{*}$$ S d ∗ for all cases considered here.

Numerical Simulation of the Free-Surface Turbulent Flow around a VLCC Ship Hull

2007 ◽  
Author(s):  
Adrian Lungu ◽  
Theodore E. Simos ◽  
George Psihoyios ◽  
Ch. Tsitouras
Keyword(s):  
Numerical Simulation ◽  
Free Surface ◽  
Turbulent Flow ◽  
Ship Hull

Calculation and Design Method Study of the Coil-Wound Heat Exchanger

2014 ◽  
Vol 1008-1009 ◽  
pp. 850-860 ◽  
Author(s):  
Zhou Wei Zhang ◽  
Jia Xing Xue ◽  
Ya Hong Wang
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Heat Exchanger ◽  
Design Method ◽  
Fluid Velocity ◽  
Exchange Process ◽  
Three Dimensional ◽  
Simulation Method ◽  
Physical Parameters ◽  
Numerical Result

A calculation method for counter-current type coil-wound heat exchanger is presented for heat exchange process. The numerical simulation method is applied to determine the basic physical parameters of wound bundles. By controlling the inlet fluid velocity varying in coil-wound heat exchanger to program and calculate the iterative process. The calculation data is analyzed by comparison of numerical result and the unit three dimensional pipe bundle model was built. Studies show that the introduction of numerical simulation can simplify the pipe winding process and accelerate the calculation and design of overall configuration in coil-wound heat exchanger. This method can be applied to the physical modeling and heat transfer calculation of pipe bundles in coil wound heat exchanger, program to calculate the complex heat transfer changing with velocity and other parameters, and optimize the overall design and calculation of spiral bundles.

Numerical simulation of sloshing with large deforming free surface by MPS-LES method

2012 ◽  
Vol 26 (4) ◽  
pp. 653-668 ◽  
Author(s):  
Xu-jie Pan ◽  
Huai-xin Zhang ◽  
Xue-yao Sun
Keyword(s):  
Numerical Simulation ◽  
Free Surface
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