Non-contact near-field underwater explosion induced shock-wave loading of submerged rigid structures: Nonlinear compressibility effects in fluid structure interaction

2012 ◽  
Vol 112 (2) ◽  
pp. 024911 ◽  
Author(s):  
Ritwik Ghoshal ◽  
Nilanjan Mitra
Keyword(s):  
Shock Wave ◽  
Near Field ◽  
Fluid Structure Interaction ◽  
Underwater Explosion ◽  
Shock Wave Loading ◽  
Wave Loading ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Compressibility Effects

scholarly journals Structure Analysis of Marine Pipes under the Effect of Water Explosion Force (Wave)

2017 ◽  
Vol 3 (6) ◽  
pp. 442-449 ◽  
Author(s):  
Kamran Khalifehei
Keyword(s):  
Shock Wave ◽  
Numerical Modeling ◽  
Numerical Method ◽  
Structure Analysis ◽  
Underwater Explosion ◽  
Shock Wave Loading ◽  
Wave Loading ◽  
Structure Interaction ◽  
Shockwave Loading ◽  
Abaqus Software

Underwater explosion is a subject that has been paid attention to by many researchers. In this study the underwater explosion phenomena under shockwave loading is explored by numerical method. For this purpose, by modeling a marine pipe buried in the water by ABAQUS software, the effect of the shock wave and the damages were assessed. Then using the laboratorial results, the fluid-structure interaction and shock wave loading and its results were analysed. Finally, it was concluded from numerical modeling that the highest levels of strain on the pipe buried in the water under underwater explosion and shock wave loading occur in the ending parts of the pipe in both sides and away from explosion field.

Fluid Structure Interactions for Blast Wave Mitigation

2011 ◽  
Vol 78 (3) ◽  
Author(s):  
Wen Peng ◽  
Zhaoyan Zhang ◽  
George Gogos ◽  
George Gazonas
Keyword(s):  
Shock Wave ◽  
Blast Wave ◽  
Fluid Structure Interaction ◽  
Wave Formation ◽  
Plate Motion ◽  
Fluid Structure Interactions ◽  
Free Standing ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Shock Wave Formation

The dynamic response of a free-standing plate subjected to a blast wave is studied numerically to investigate the effects of fluid-structure interaction (FSI) in blast wave mitigation. Previous work on the FSI between a blast wave and a free-standing plate (Kambouchev, N., et al., 2006, “Nonlinear Compressibility Effects in Fluid-Structure Interaction and Their Implications on the Air-Blast Loading of Structures,” J. Appl. Phys., 100(6), p. 063519) has assumed a constant atmospheric pressure at the back of the plate and neglected the resistance caused by the shock wave formation due to the receding motion of the plate. This paper develops an FSI model that includes the resistance caused by the shock wave formation at the back of the plate. The numerical results show that the resistance to the plate motion is especially pronounced for a light plate, and as a result, the previous work overpredicts the mitigation effects of FSI. Therefore, the effects of the interaction between the plate and the shock wave formation at the back of the plate should be considered in blast wave mitigation.

Fluid-Structure Interaction for Hydrodynamic Problems: Impact Between a Tanker Bow Flare and a Submarine

2002 ◽  
Author(s):  
N. Aquelet ◽  
H. Lesourne ◽  
M. Souli
Keyword(s):  
Fluid Structure Interaction ◽  
Underwater Explosion ◽  
Slip Boundary Condition ◽  
Industrial Applications ◽  
Structural Deformation ◽  
Nuclear Submarine ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Slip Boundary ◽  
Eulerian Formulation

A methodology to predict the capacity of a nuclear submarine hull to act as a protective container and energy absorber under impact by an another underwater structure is needed. Principia Marine, company of Research in Shipbuilding (formerly IRCN, Institut de Recherche en Construction Navale), is responding to this need by developing an underwater impact crash prediction methodology based upon LS-DYNA3D software. Several physical phenomena with their own characteristic times follow one another at the time of the shock. So different but complementary tasks to develop this methodology were worked individually. This paper deals with contribution to this ongoing program that breaks up into two objectives. The first goal aims to highlight the effect of water on the structural deformation at the time of the collision between a nuclear submarine and a tanker ram bow, which is generally plane. The two-dimensional modelling of this collision uses an Eulerian formulation for the fluid and a Lagrangian formulation for the structure. The fluid-structure interaction is treated by an Euler/Lagrange penalty coupling. This method of coupling, which makes it possible to transmit the efforts in pressure of the Eulerian grid to the Lagrangian grid and conversely, is relatively a recent algorithmic development. It was successfully used in many scientific and industrial applications: the modelling of the attack of birds on the fuselage of a Jet for the Boeing Corporation, the underwater explosion shaking the oil platforms, and airbag simulation… The requirements of modelling for this algorithm are increasingly pointed. Thus, the second objective of this paper is to compare the results in pressures and velocities near the bulb for two cases, in the first one, the bulb is modelled by a slip boundary condition, in the second one, the bulb is a rigid Lagrangian structure, which involves the use of the Euler/Lagrange penalty coupling.

Damping Effect in Fluid-Structure Interaction: Application to Slamming Problem

2003 ◽  
Author(s):  
N. Aquelet ◽  
M. Souli
Keyword(s):  
High Pressure ◽  
Physical Phenomenon ◽  
Fluid Structure Interaction ◽  
Underwater Explosion ◽  
Industrial Applications ◽  
Damping Factor ◽  
Local Pressure ◽  
Shipbuilding Industry ◽  
Fluid Structure ◽  
Structure Interaction

During a high velocity impact of a structure on an incompressible fluid, impulse loads with high pressure peaks occur. This physical phenomenon called ‘slamming’ is a concern in the shipbuilding industry because of the possibility of hull damage. Shipbuilding companies are carrying out several studies on the slamming modeling using FEM software. This paper presents the prediction of the local high pressure load on a wedge striking a free surface. The fluid-structure interaction is simulated by a fluid-structure coupling algorithm. This method of coupling, which makes it possible to transmit the efforts in pressure from the Eulerian grid to the Lagrangian grid and vice versa, is a relatively recent algorithmic development. It was successfully used in many scientific and industrial applications: the modeling of the bird strike on the fuselage of a Jet for the Boeing Corporation, underwater explosion shaking the oil platforms, and airbag simulation in automotive industry... Predicting the local pressure peak on the structure requires an accurate fluid-structure interaction algorithm. Thus, some penalty coupling enhancements make the slamming modeling possible. The main improvement is a numerical damping factor which permits to smoothing of the pressure signal.

scholarly journals Hydroelastic behaviour of a structure exposed to an underwater explosion

2015 ◽  
Vol 373 (2033) ◽  
pp. 20140103 ◽  
Author(s):  
G. Colicchio ◽  
M. Greco ◽  
M. Brocchini ◽  
O. M. Faltinsen
Keyword(s):  
Fluid Structure Interaction ◽  
Three Dimensional ◽  
Underwater Explosion ◽  
Computational Effort ◽  
Elastic Plates ◽  
Fluid Structure ◽  
Flow Solver ◽  
Structure Interaction ◽  
Hydroelastic Interaction ◽  
Acoustic Phase

The hydroelastic interaction between an underwater explosion and an elastic plate is investigated num- erically through a domain-decomposition strategy. The three-dimensional features of the problem require a large computational effort, which is reduced through a weak coupling between a one-dimensional radial blast solver, which resolves the blast evolution far from the boundaries, and a three-dimensional compressible flow solver used where the interactions between the compression wave and the boundaries take place and the flow becomes three-dimensional. The three-dimensional flow solver at the boundaries is directly coupled with a modal structural solver that models the response of the solid boundaries like elastic plates. This enables one to simulate the fluid–structure interaction as a strong coupling, in order to capture hydroelastic effects. The method has been applied to the experimental case of Hung et al. (2005 Int. J. Impact Eng. 31 , 151–168 ( doi:10.1016/j.ijimpeng.2003.10.039 )) with explosion and structure sufficiently far from other boundaries and successfully validated in terms of the evolution of the acceleration induced on the plate. It was also used to investigate the interaction of an underwater explosion with the bottom of a close-by ship modelled as an orthotropic plate. In the application, the acoustic phase of the fluid–structure interaction is examined, highlighting the need of the fluid–structure coupling to capture correctly the possible inception of cavitation.

scholarly journals The influence of fluid–structure interaction on cloud cavitation about a rigid and a flexible hydrofoil. Part 3

2022 ◽  
Vol 934 ◽  
Author(s):  
Yin Lu Young ◽  
Jasmine C. Chang ◽  
Samuel M. Smith ◽  
James A. Venning ◽  
Bryce W. Pearce ◽  
...  
Keyword(s):  
Shock Wave ◽  
Dynamic Load ◽  
Fluid Structure Interaction ◽  
Cavitation Number ◽  
Cloud Cavitation ◽  
Fluid Structure ◽  
Driven Cavity ◽  
Structure Interaction ◽  
Cavity Shedding ◽  
Lock In

Experimental studies of the influence of fluid–structure interaction on cloud cavitation about a stiff stainless steel (SS) and a flexible composite (CF) hydrofoil have been presented in Parts I (Smith et al., J. Fluid Mech., vol. 896, 2020a, p. A1) and II (Smith et al., J. Fluid Mech., vol. 897, 2020b, p. A28). This work further analyses the data and complements the measurements with reduced-order model predictions to explain the complex response. A two degrees-of-freedom steady-state model is used to explain why the tip bending and twisting deformations are much higher for the CF hydrofoil, while the hydrodynamic load coefficients are very similar. A one degree-of-freedom dynamic model, which considers the spanwise bending deflection only, is used to capture the dynamic response of both hydrofoils. Peaks in the frequency response spectrum are observed at the re-entrant jet-driven and shock-wave-driven cavity shedding frequencies, system bending frequency and heterodyne frequencies caused by the mixing of the two cavity shedding frequencies. The predictions capture the increase of the mean system bending frequency and wider bandwidth of frequency modulation with decreasing cavitation number. The results show that, in general, the amplitude of the deformation fluctuation is higher, but the amplitude of the load fluctuation is lower for the CF hydrofoil compared with the SS hydrofoil. Significant dynamic load amplification is observed at subharmonic lock-in when the shock-wave-driven cavity shedding frequency matches with the nearest subharmonic of the system bending frequency of the CF hydrofoil. Both measurements and predictions show an absence of dynamic load amplification at primary lock-in because of the low intensity of cavity load fluctuations with high cavitation number.

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