In particular, threat from low intensity to high intensity underwater explosion. There are features like underwater explosion bubble modeling, effective solvers and substructure capability to name a few which ensures that the design can be studied for predicting the behavior of ships under different conditions. Naturally, the waves produced by a downward surface elevation impulse, or via an underwater explosion. Numerical simulation of surface ship hull beam whipping. Costanzo naval surface warfare center carderock division, uerd 9500 macarthur boulevard west bethesda, md 208175700 301 2271650 nomenclature c0 nominal sound speed d depth of charge e exponential function e energy flux density ft feet gcc grams per cubic centimeter. Ship shock modelling and simulation for farfield underwater.
Underwater explosion part i 2008 henry tan 1 underwater explosion 1 introduction an underwater explosion is an explosion where the point of detonation is below the surface of the water. Three simulation cases are modelled using a numerical simulation software, autodyn 2d in order to predict the plate deformations under blast loading. Numerical simulations of exposed circular surface of. It is generally very difficult to simulate underwater explosion phenomena by using traditional gridbased numerical methods due to the inherent features such as large deformations, large inhomogeneities, moving interface and so on. As a trusted partner, msc software helps companies improve quality, save time, and reduce costs associated with design and test of manufactured products. Underwater implosion and explosion stanford university. In this paper, the smoothed particle hydrodynamics sph method is used to address the simulation of a fully explicit threedimensional 3d underwater explosion in a rigid or deformable cylinder, incorporating properly the. Underwater explosion performance of rdxapbased aluminized. Numerical simulation study of target response under. Business wire june 24, 2014 msc software corporation, a global leader in helping product manufacturers to advance their engineering methods with simulation software. Numerical simulation of underwater explosions sciencedirect. Abaqus integrates noise simulation within the finite element solver, allowing fully coupled structuralacoustic simulations to be performed within familiar abaqus workflows.
In 1993, germany provided the software to the united states for evaluation. International waters are increasingly under threat thereby creating the need to protect high value naval and commercial vessels and more importantly human lives at sea. The simulation is that of deflagration steady burn and never transitions to a detonation. A semiempirical method to determine jwl state equation parameters was given. Underwater explosion simulation simulations are increasingly supplanting expensive livefire explosive testing in the design and analysis of ships and offshore structures. Numerical simulation of underwater explosions 911 the results provided by the numerical method show a complicated pattern of pressure distributions in the region close to the cylindrical charge due to the interaction of pressure fronts from different parts of the charge. Within the analysis, the effects from both first shock wave and.
Mar 01, 2017 this is a modeling and simulation representation of an underwater explosion event during a ship shock trial, the standard test used for shock qualification in accordance with mils901. The damage to a structure due to an underwater explosion, which must necessarily include the phenomenon of cavitation, is a difficult problem to simulate. Study on the pressure characteristics of shock wave. The effects of an underwater explosion on the sea turtles lepidochelys kempi and caretta caretta with observations of effects on other marine organisms.
To understand the underwater explosion undex performance of rdxapbased aluminized explosives. Influences of artificial viscosity and mesh density. Built upon classic mathematical models, numerical simulation software is a wellestablished timesaving tool for yielding precise undex results, leaving aside the need for resource costly experimental tests. Through numerical analysis of a typical underwater tnt explosion problems, the effects of the quadratic and linear viscosity on the key phenomenon of this. Physicsbased modeling and simulation for the prediction. A numerical investigation of bubble dynamics based on the potentialflow theory. Engineers use finite element method analysis software to verify designs using ddam computer simulations that model the known characteristics of underwater explosion phenomena as well as the surface ship or submarine body responses to shock loading and application of a shock spectra in order to apply the appropriate shock responses at the. Msc software provides a family of high performance solutions for fea that meet the needs of experienced experts and designers, new engineers, and everyone in between. The focus of this multiuniversity project is the study of intense implosive collapses of airfilled underwater structures and their effects on nearby structures. Msc softwares dytran explicit nonlinear fea helps indian. Numerical simulation of tnt underwater explosion was carried out with autodyn software. Surface ship shock simulation subjected to underwater explosion is generally complicated by free surface effects such as surface reflection wave resulting bulk cavitation.
Modeling underwater explosion undex shock effects for. An underwater explosion is an obvious potential threat to a nearby submarine as consequent strong shock waves can lead to the structural failure of the submarine hull. Could anyone tell me any info about underwater explosion undex. Physicsbased modeling and simulation for the prediction of. Ship shock modelling and simulation for farfield underwater explosion. The effects of an underwater explosion are depend upon many parameters such as explosive strength i.
Software tool enables highfidelity simulation of explosive. Structuralacoustic interaction covers diverse application areas including noise transmission, radiation, acoustic attenuation or amplification. Based on the ale arbitrary lagrangeeuler algorithm, the full coupled model, including the propagation of shock wave and the interaction between water and dam, was used. The explosion simulations were performed by jim guilkey and todd harman. Aces simulation helped determine that an underwater. You can find some of the details of the fluidstructure interaction algorithm in our paper an eulerianlagrangian approach for simulating explosions of energetic devices. Dynamic response of the noncontact underwater explosions. Livermore software technology corporation, livermore, ca, june, 1997. The san antonio business journal features local business news about san antonio.
Lagrangianeulerian ale method of lsdyna software to simulate the processes of nearfield underwater explosion. Simulation underwater explosion undex abaqus youtube. One immediately obvious need was for more flexibility in the constitutive representation for materials in shell elements. Not to mention, most simulation software yes even naiad and realflow go haywire when you push it beyond certain limits like pulling or pushing large objects at very high velocity through the simulation grid however, using naiad or realflow is the best option to get as close to a couple of base splashes that feel right and then merge them. Sea waving can be sufficiently exactly modeled by means of statistical methods. Survey on experimental and numerical approaches to.
Dynamical response simulation of concrete dam subjected to. Simulation of underwater explosion benchmark experiments with. In addition, hull cavitation, gas bubble oscillation and migration toward free surface, and cavitation closure pulses. The analysis uses a form of shock spectrum analysis that estimates the dynamic response of a component to shock loading caused by the sudden movement of a naval vessel. Hunley was an experimental submarine built by confederate civilian engineers during the civil war. Irs chooses msc softwares solution for underwater explosion. I think explosion simulations are based on euler equations, so therefore i think i can run an explosion simulation on openfoam. Simulation of pressurespacetime history in underwater. It was designed to submerge beneath an enemy vessel while towing a torpedo behind, which would strike the hull and detonate. I saw underwater explosion model in abaqus by acoustic simulation. Underwater explosion performance of rdxapbased aluminized explosives dalin xiang, jili rong, xuan he, zhiwei feng school of aerospace engineering, beijing institute of technology, beijing,81, p. Underwater explosion and implosion, fluidstructure. Built upon classic mathematical models, numerical simulation software is a.
The autodyne numerical simulation software was used to calculate the dynamic response of target under the underwater explosion. Numerical calculation method based on the abaqus software, the acousticstructure coupling method is used to calculate the propagation of the underwater explosion pressur e in water and the interaction between the ship swet surfaceandthesurroundingwater. Simulations for the explosion in a waterfilled tube. Nesm continues to pursue a significant verification and validation program.
Farfield explosions have a significant effect in terms of damage to equipment and mission capability of a ship. Detonation waves in explosive and shock wave in water during early time of explosion are high frequency waves. Any advice on explosion detonation simulation or modelling. A 9 kt mk7 was detonated at a depth of 500 ft 150 m in deep water. Smoothed particle hydrodynamics for numerical simulation of. Jan 22, 2018 the cost of the full video,inp file,cae file is 20 usd send an email to buy these files full video, inp file, cae file email. Study on jwl equation of state for the numerical simulation. Study of explosion loads of nearfield underwater explosion.
Studying the structural dynamic response characteristics under the action of underwater explosion load had great significance for improving the antiexplosion and antiimpact performance of ships. To this end, a computational framework is being developed, combining contact and cracking of thin structures, as well as compressible multiphase flow solvers and looselycoupled fluidstructure timeintegrators. Numerical simulation is a more convenient method to study underwater explosion problem. Calibration of numerical simulation methods for underwater. A series of movable observation points are set on the target and the y. The centrifugal underwater explosion tests and corresponding numerical simulations were. Studying the structural dynamic response characteristics under the action of underwater explosion load had great significance for improving the anti explosion and antiimpact performance of ships. Underwater explosion are categorized in accordance with their depth beneath the waters surface, because this has a strong influence on their effects. Underwater explosive load calculation and numerical simulation is the key issues of the design of underwater conventional weapons and protection of ships and submarine. Experimental and numerical investigation of the dynamics. Hamashima kumamoto university 2391 kurokami, kumamoto 8608555, japan k. Depending upon depth of explosion source underwater explosion is classified as deep and shallow underwater explosion. Tnt explosion simulation cfd online discussion forums. Through years of theoretical and experimental investigations of free surface problems including surface waves, ship maneuvering, propulsor thrust enhancement, and ship interactions with each other and with the surroundings, we have developed numerical codes that can predict flow fields for many types of free surface related problems.
The shock hardening testing culminates in a full ship shock trial fsst, in which an underwater explosive charge is set off near an operational ship, and system and component failures are documented. This is described in more detail in a recent invited journal publication. The lsdyna software was employed to simulate the dynamic response of concrete dam subjected to contact explosion load. The influence on numerical results caused by factors such as state equation of water, boundary condition, and mesh size was analyzed by comparing with the. Results are compared with those obtained experimentally elsewhere.
This is a modeling and simulation representation of an underwater explosion event during a ship shock trial, the standard test used for shock qualification in accordance with mils901. Sph for underwater explosion shock simulation on globalspec. Based on the ale arbitrary lagrangeeuler algorithm, the full coupled model, including the propagation of shock wave. Once the load arrives at the ship hull, the interaction between the ships. Msc software is one of the ten original software companies and a global leader in helping product manufacturers to advance their engineering methods with simulation software and services. Underwater explosion arising from high explosive detonation consists of a complicated sequence of energetic processes. Through the simulation of the interaction of the underwater explosion bubble, the generated waves and the floating body based on the presented model, the influences of the buoyancy parameter and. The pool fire simulations were performed by phil smith and his group. Numerical simulation of surface ship hull beam whipping response due to submitted to underwater explosion by ssuchieh tsai this study presents a method to evaluate the whipping response of a surface ship subjected to an underwater explosion. This software has been extensively validated and shown to accurately mathematically reproduce the effects of. Influences of artificial viscosity and mesh density on simulation results were discussed. In this paper, the coupled eulerianlagrangian cel method in autodyn is used to simulate the process of shock wave propagation and solve fsi problems.
The dynamic design analysis method ddam is a us navydeveloped analytical procedure for evaluating the design of equipment subject to dynamic loading caused by underwater explosions undex. One of the most prominent pieces of modeling software is the us navys dysmas dynamic system mechanics advanced simulation hydrocode, which uses the gemini eulerian solver to model the pressures resulting from underwater blasts. With the deepening of the study of damage effect of marine weapons and anti blast protection of ships, the problem of nearfield underwater explosion and contact underwater explosion has gradually become the focus of the current underwater explosion research. Msc software s dytran explicit nonlinear fea helps indian register of shipping predict responses of ship structures subjected to underwater explosion newport beach, ca. Kato nof corporation 611 kitakomatsudani, taketoyocho, chitagun, aichi 4702398, japan state of detonation products is described by various types of equations of state. Numerical simulations of exposed circular surface of rolled. Business wire june 24, 2014 msc software corporation, a global leader in helping product manufacturers to advance their engineering methods with simulation software and services, today announced that indian register of shipping irs, an internationally recognized independent ship classification society, has selected msc softwares dytran explicit nonlinear. Structural acoustic simulation abaqus dassault systemes. Powered by a hand crank operated by seven men with one pilot, the 40foot long boat was built of wrought iron boiler plate with custom cast iron fittings.
Nukemap is a mapping mashup that calculates the effects of the detonation of a nuclear bomb. Numerical simulation of underwater explosions using an ale. Numerical simulation of underwater explosion loads. Numerical modeling of underwater explosion by onedimensional. Numerical simulation of underwater explosion loads springerlink. Sph simulation of waves associated with underwater explosion. Simuserv pioneer in cae, simulation software, operating. This article presents numerical simulation of underwater explosions using a onedimensional wedge model of ansysautodyn explicit software for nonlinear dynamics, provided by ansys century dynamics, inc. Business wire june 24, 2014 msc software corporation, a global leader in helping product manufacturers to advance their engineering methods with simulation software and services, today announced that indian register of shipping irs, an internationally recognized.
This thesis describes and assesses a simplified tool for modeling underwater explosion shock effects during earlystage naval ship design. Introduction minehunters are subjected to specific sea loads due to waving and dynamical impacts associated with underwater explosion. Navy ship underwater shock prediction and testing capability. Study of explosion loads of nearfield underwater explosion the. The simulation results by using three empirical formulas were compared and shins or coles empirical formula was shown to be better than the other empirical formulations when subjected to an undex under the same conditions. Unpublished report submitted to national marine fisheries service biological laboratory, galveston, texas.
An example of a deep underwater explosion is the wahoo test, which was carried out in 1958 as part of operation hardtack i. These solutions help companies meet their business challenges by helping engineers gain deeper insight in their products through virtual testing. The dynamic system mechanics advanced simulation dysmas software, developed in germany, took an innovative approach to predicting underwater explosion effects and the response of naval targets. However, the accuracy is deeply affected by some factors such as state equation of water, boundary condition, and mesh size. Underwater explosion simulations from autodyn software.
Software corporation 2300 traverwood drive ann arbor, mi 48105 734 9943800 this paper describes the numerical simulation of a cylinder submerged under water subjected to explosion using msc. The propagation of the shock wave across multilayer structures during underwater explosion is a very complex physical phenomenon, involving violent fluidstructure interaction fsi problems. Underwater explosion phenomena and shock physics frederick a. Use vpg lsdyna software alefsi fluidstructure coupling of the abovedescribed method can be carried out several aspects related to numerical simulation.
The analytical results offer a valuable reference to the research of underwater explosion. Pressurespacetime history of shock waves due to the detonation of explosive charge in water is obtained by simulating the numerical integration of shock trajectory with the variation of fluid parameters behind the shock front. Fine meshes less than 1,mm in explosive and water nearby, and small linear viscosity. Jun 26, 2014 indian register of shipping irs has selected msc software s dytran explicit nonlinear simulation solution for underwater explosion analysis. Overview in chapter 6, the sph method is applied to simulate the complicated explosion process arising from high explosive he detonation. Simulation of the underwater nuclear explosion and its. Engineers using mscs structural analysis programs are able to evaluate many. The solid mechanics involved in these simulations was my contribution. An underwater explosion also known as an undex is a chemical or nuclear explosion that occurs under the surface of a body of water. The centrifugal underwater explosion tests and corresponding numerical simulations were carried out to study the laws of shock wave and bubble pulsation. Some studies have been conducted for numerical influence factors.