scholarly journals Numerical study on breaking solitary wave force on box-girder bridge

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Wanli Yang ◽  
Sijing Li ◽  
Junling Liu ◽  
Wenbo Wu ◽  
Hui Li ◽  
...  
Keyword(s):  
Solitary Wave ◽  
Static Pressure ◽  
Numerical Study ◽  
Wave Force ◽  
Generation Mechanism ◽  
Bridge Engineering ◽  
Vertical Force ◽  
Horizontal Force ◽  
Box Girder ◽  
Force Calculation

AbstractSolitary wave is often used to simulate tsunami propagating in deep water and breaking solitary wave is often used to simulate tsunami bore propagating in shallow water or on land. The breaking solitary wave force on box-girder, which has been widely used in bridge engineering in coastal areas of China, receives few attentions. This study aims to investigate characteristics and generation mechanism of breaking solitary wave force on box-girder numerically. A numerical wave flume with a 1:20 slope was built firstly, then the solitary wave generation ability, wave deformation and wave breaking on the slope, as well as wave force calculation precision, are validated. The water depth 0.6 m, the slope gradient 1:20 and the distance between slope top and box-girder 2.0 m remain unchanged, while the wave height and clearance changes in different cases. The time histories of horizontal force and vertical force on box-girder can be divided into three and four stages respectively according to their characteristics. The surface of box-girder is decomposed into a series of panels to facilitate exploring tsunami bore force generation mechanism. Results show horizontal force is dominated by static pressure on upstream vertical panels and vertical force is mainly contributed by static pressure on upstream horizontal panels and on panels in the chambers. Tsunami bore overtopping the box-girder deck impacts the top panel vigorously and results in the peak value of negative vertical force.

scholarly journals 3D Numerical Investigation of Forces and Flow Field around the Semi-Submersible Platform in An Internal Solitary Wave

Water ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 208 ◽  
Author(s):  
Weiye Ding ◽  
Congfang Ai ◽  
Sheng Jin ◽  
Jinbo Lin
Keyword(s):  
Experimental Data ◽  
Solitary Wave ◽  
Flow Fields ◽  
Propagation Direction ◽  
Internal Solitary Wave ◽  
Vertical Force ◽  
Horizontal Force ◽  
Numerical Wave Tank ◽  
Numerical Wave ◽  
Almost All

Characteristics of hydrodynamic forces and flow fields around the semi-submersible platform induced by the internal solitary wave (ISW) propagation were investigated in a 3D numerical wave tank. Good agreements between numerical results and experimental data of forces and torque on the platform were achieved. The hydrodynamic loads increased and decreased with the increases in the ISW amplitude and fluid depth ratio, respectively. The pressure mainly contributed to the force on the platform. The horizontal forces on bracings were negligible. Almost all the vertical forces on the platform were derived from those on pontoons. The horizontal force and torque on the platform increased with the increases in the angle between the platform symmetrical axis and the ISW propagation direction. The platform subjected the maximum vertical force when the angle was 0°. There were obvious velocity reductions around the platform during the ISW propagation, as visible vortexes shedding around the platform could be observed. Complexities of the distributions of flow fields around the platforms located at the 30°- and 60°-direction were greater than those around the platforms located at the 0°- and 90°-direction. Flow fields around the same kind components of each platform located at different angles were similar.

Surface Evolution and Wave Loads on a Horizontal Plate in Different Tsunami-like Waves

2020 ◽  
Vol 14 (05) ◽  
pp. 2040001
Author(s):  
Qian Wang ◽  
Yong-Liu Fang ◽  
Hua Liu
Keyword(s):  
Solitary Wave ◽  
Wave Force ◽  
Hydrodynamic Characteristics ◽  
Vertical Force ◽  
Wave Loads ◽  
Horizontal Plate ◽  
Local Pressure ◽  
Surface Evolution ◽  
Undular Bore ◽  
Physical Experiments

Physical experiments are conducted to study the interaction between the tsunami-like waves and the horizontal plate. The surface evolution and wave-induced loads are measured to explore the hydrodynamic characteristics when different waves are employed to simulate the tsunami. The solitary wave, surge wave, and undular bore are generated in laboratory as the simplification of the offshore tsunami wave. The bottom-fixed plate places near the free surface. It is found that the elevated plate attenuates the solitary waves locally, while the submerged plate leads to the wave focus phenomenon. The plate has less influence on the surface variation of the surge wave propagating. Results of loads show the different loading process of each tsunami-like wave. The inertial wave force and the local pressure from the rising surface dominate the inline force and vertical force, respectively. The value of loads induced by the surge wave is less than that of the solitary wave. The undular bore is generated by the superimposition of the solitary wave on the surge wave. The part of the solitary wave plays a local role in the wave force, while the surge part dominates the surface evolution.

Fore-Aft Forces in Tire-Wheel Assemblies Generated by Unbalances and the Influence of Balancing

1991 ◽  
Vol 19 (3) ◽  
pp. 142-162 ◽  
Author(s):  
D. S. Stutts ◽  
W. Soedel ◽  
S. K. Jha
Keyword(s):  
Mathematical Model ◽  
Elastic Foundation ◽  
Torsional Oscillation ◽  
Vertical Direction ◽  
Torsional Stiffness ◽  
Rolling Motion ◽  
Vertical Force ◽  
Horizontal Force ◽  
Wheel Rim ◽  
Open Question

Abstract When measuring bearing forces of the tire-wheel assembly during drum tests, it was found that beyond certain speeds, the horizontal force variations or so-called fore-aft forces were larger than the force variations in the vertical direction. The explanation of this phenomenon is still somewhat an open question. One of the hypothetical models argues in favor of torsional oscillations caused by a changing rolling radius. But it appears that there is a simpler answer. In this paper, a mathematical model of a tire consisting of a rigid tread ring connected to a freely rotating wheel or hub through an elastic foundation which has radial and torsional stiffness was developed. This model shows that an unbalanced mass on the tread ring will cause an oscillatory rolling motion of the tread ring on the drum which is superimposed on the nominal rolling. This will indeed result in larger fore-aft than vertical force variations beyond certain speeds, which are a function of run-out. The rolling motion is in a certain sense a torsional oscillation, but postulation of a changing rolling radius is not necessary for its creation. The model also shows the limitation on balancing the tire-wheel assembly at the wheel rim if the unbalance occurs at the tread band.

Numerical investigations on the effect of volute casing treatment for performance augmentation in a centrifugal fan

2021 ◽  
pp. 095440622110341
Author(s):  
Manjunath L Nilugal ◽  
K Vasudeva Karanth ◽  
Madhwesh N
Keyword(s):  
Total Pressure ◽  
Static Pressure ◽  
Numerical Study ◽  
Pressure Coefficient ◽  
Three Dimensional ◽  
Pressure Rise ◽  
Centrifugal Fan ◽  
Casing Treatment ◽  
Sliding Mesh ◽  
Optimum Configuration

This article presents the effect of volute chamfering on the performance of a forward swept centrifugal fan. The numerical analysis is performed to obtain the performance parameters such as static pressure rise coefficient and total pressure coefficient for various flow coefficients. The chamfer ratio for the volute is optimized parametrically by providing a chamfer on either side of the volute. The influence of the chamfer ratio on the three dimensional flow domain was investigated numerically. The simulation is carried out using Re-Normalisation Group (RNG) k-[Formula: see text] turbulence model. The transient simulation of the fan system is done using standard sliding mesh method available in Fluent. It is found from the analysis that, configuration with chamfer ratio of 4.4 is found be the optimum configuration in terms of better performance characteristics. On an average, this optimum configuration provides improvement of about 6.3% in static pressure rise coefficient when compared to the base model. This optimized chamfer configuration also gives a higher total pressure coefficient of about 3% validating the augmentation in static pressure rise coefficient with respect to the base model. Hence, this numerical study establishes the effectiveness of optimally providing volute chamfer on the overall performance improvement of forward bladed centrifugal fan.

scholarly journals Report of the Kew Committee for the fourteen months ending December 31, 1891

1892 ◽  
Vol 51 (308-314) ◽  
pp. 152-182
Keyword(s):  
Vertical Force ◽  
Horizontal Force ◽  
Increased Activity

The operations of The Kew Observatory, in the Old Deer Park, Richmond, Surrey, are controlled by the Kew Committee, which is constituted as follows: The magnetographs have worked satisfactorily all through since last report. The curves obtained, representing Declination, Horizontal Force, and Vertical Force, have shown a marked increased activity in terrestrial magnetic changes as compared with the preceding year, although no very large disturbances have been registered.

A Numerical Study on the Reflection of a Solitary Wave in Shallow Water

1982 ◽  
Vol 51 (3) ◽  
pp. 1018-1023 ◽  
Author(s):  
Mitsuaki Funakoshi ◽  
Masayuki Oikawa
Keyword(s):  
Solitary Wave ◽  
Shallow Water ◽  
Numerical Study

Hydrodynamic coefficients of a floater near a partially reflecting seawall in the presence of an array of caisson blocks

2021 ◽  
pp. 1-23
Author(s):  
K G Vijay ◽  
Santanu Koley ◽  
Kshma Trivedi ◽  
Chandra Shekhar Nishad
Keyword(s):  
Wave Scattering ◽  
Structural Parameters ◽  
Wave Force ◽  
Vertical Force ◽  
Hydrodynamic Coefficients ◽  
Floating Structure ◽  
Surface Gravity Wave ◽  
Damping Coefficients ◽  
Half Wavelength ◽  
Scattering And Radiation

Abstract In the present study, surface gravity wave scattering and radiation by a freely floating rectangular buoy placed near a partially reflecting seawall and in the presence of an array of caisson blocks are analyzed. Various hydrodynamic parameters related to the wave scattering and radiation, such as the added mass and radiation damping coefficients, correspond to sway, heave and roll motions of the floating buoy, horizontal force, vertical force and moment acting on the floating structure, and horizontal wave force acting on the partially reflecting seawall are studied for a variety of wave and structural parameters. The study reveals that the resonating pattern in various hydrodynamic coefficients occurs for moderate values of the wavenumber. Further, when the distance between the floater and the sidewall is an integral time of half wavelength, the resonating behavior in the sway, heave and roll added masses, and associated damping coefficients appears, and the aforementioned hydrodynamic coefficients change rapidly around this zone. These resonance phenomena can be diminished significantly with appropriate positioning of the floater with respect to the sidewall and in the presence of partially reflecting seawall.

Study on generation mechanism of vertical force peak values on T-girder attacked by tsunami bore

2020 ◽  
Vol 196 ◽  
pp. 106782 ◽  
Author(s):  
Wanli Yang ◽  
Wenjie Lai ◽  
Quanlong Zhu ◽  
Chuanjiang Zhang ◽  
Fuhai Li
Keyword(s):  
Generation Mechanism ◽  
Vertical Force ◽  
Force Peak
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