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.

Mitigation of Sliding Motion of a Cask-Canister by Fluid-Structure Interaction in an Annular Region

2011 ◽  
Author(s):  
Tomohiro Ito ◽  
Yoshihiro Fujiwara ◽  
Atsuhiko Shintani ◽  
Chihiro Nakagawa ◽  
Kazuhisa Furuta
Keyword(s):  
Equations Of Motion ◽  
Fluid Structure Interaction ◽  
Shaking Table ◽  
Annular Region ◽  
Test Model ◽  
Free Standing ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Sliding Motion ◽  
Standing Structure

The cask-canister system is a coaxial circular cylindrical structure in which several spent fuels are installed. This system is a free-standing structure thus, it is very important to reduce sliding motion for very large seismic excitations. In this study, we propose a mitigation method for sliding motion. Water is installed in an annular region between a cask and a canister. The equations of motion are derived taking fluid-structure interaction into consideration for nonlinear sliding motion analyses. Based on these equations, mitigation effects of sliding motions are studied analytically. Furthermore, a fundamental test model of a cask-canister system is fabricated and shaking table tests are conducted. From the analytical and test results, sliding motion mitigation effects are investigated.

Analysis of Fluid-Structure Interaction of an Elastic Blade in Cascade

2002 ◽  
Author(s):  
R. C. K. Leung ◽  
Y. L. Lau ◽  
R. M. C. Si
Keyword(s):  
Numerical Technique ◽  
Fluid Structure Interaction ◽  
Uniform Flow ◽  
Frequency Parameter ◽  
Generation Process ◽  
Noise Generation ◽  
Fluid Structure Interactions ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Normalized Frequency

A time-marching numerical model for the analysis of fluid-structure interaction caused by oncoming alternating vortices has been developed by Jadic et al. (1998). Its applicability to analyzing realistic fluid–structure interaction problems has successfully been established in a recent experimental work of a flat plate in a circular cylinder wake (Lau et al. 2002). Using the model, So et al. (1999) have predicted that, under the excitation of oncoming Karman vortex street (KVS) vortices, an elastic airfoil/blade in inviscid uniform flow exhibits two types of fluid–structure resonance, namely aerodynamic and structural resonance. Aerodynamic resonance is of pure aerodynamic origin and occurs with rigid airfoil/blade excited at normalized frequency parameter c/d = 0.5, 1.5, 2.5 etc., where c is the blade chord and d is the streamwise separation between two neighboring vortices. For an elastic airfoil/blade, as a result of coupled fluid–structure interaction, structural resonance occurs at a normalized frequency close to the natural frequency in vacuo of the airfoil/blade. The occurrence of fluid-structure resonance has also been shown critical in noise generation process (Leung & So 2001). The present study extends the scope of the analysis to fluid–structure interactions occurring in axial–flow turbomachine cascade. When the flow is passing through the rotor, it generates wakes containing KVS vortices behind the rotor blades. The convecting wake will induce perturbations on the downstream stator blades at a wake passing frequency (Rao 1991). Such wake–blade interaction is important in determining the fatigue life of the blades and noise generation of the cascade. The cascade analysis starts with modeling the two-dimensional turbine stator by five high–loading blades evenly separated by s in inviscid uniform flow. Oncoming KVS vortices are released upstream to represent the passing wake originating from the rotor, and are allowed to pass through the stator blades. The blade pitch to blade chord ratio s/c and normalized frequency parameter c/d are important parameters of the problems. Fluid–structure interactions are fully resolved by the same numerical technique (Jadic et al. 1998, So et al. 1999). The combined effects of s/c and c/d on the aerodynamic and structural responses of the central blade are studied and discussed.

Cerebrospinal Fluid-Structure Interactions: The Development of Mathematical Models Accessible to Clinicians

2014 ◽  
Author(s):  
Novak S. J. Elliott
Keyword(s):  
Cerebrospinal Fluid ◽  
Mathematical Models ◽  
Clinical Application ◽  
Fluid Structure Interaction ◽  
Pressure Vessels ◽  
Fluid Structure Interactions ◽  
Research Methodologies ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Perceived Complexity

Physical scientists work with clinicians on biomechanical problems, yet the predictive capabilities of mathematical models often remain elusive to clinical collaborators. This is due to both conceptual differences in the research methodologies of each discipline, and the perceived complexity of even simple models. This limits expert medical input, affecting the applicability of the results. Moreover, a lack of understanding undermines the medical practitioner’s confidence in modeling predictions, hampering its clinical application. In this paper we consider the disease syringomyelia, which involves the fluid-structure interaction of pressure vessels and pipes, as a paradigm of the nexus between the modeling approaches of physical scientists and clinicians. The observations made are broadly applicable to cross-disciplinary research between engineers and non-technical specialists, such as may occur in academic-industrial collaborations.

Nanoscale Fluid-Structure Interactions in Cytoplasm During Freezing

2012 ◽  
Author(s):  
Altug Ozcelikkale ◽  
Bumsoo Han
Keyword(s):  
Theoretical Model ◽  
Physical Properties ◽  
Spatial Heterogeneity ◽  
Fluid Structure Interaction ◽  
Fluid Structure Interactions ◽  
Spatial Homogeneity ◽  
Intracellular Space ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Poroelastic Material

In this study, a theoretical model is developed to simulate the biophysical events in the intracellular spaces considering the biphasic, i.e., poroelastic, behavior of the cytoplasm. Most previous studies in the cryobiology literature have modeled the biophysical response of cells to freezing assuming the spatial homogeneity of all physical properties within the intracellular space without considering fluid-structure interaction in both the intracellular and extracellular spaces. However, a few recent studies strongly indicate that spatial heterogeneity in the intracellular space occurs during freezing. We thus model the cytoplasm as a poroelastic material considering nanoscale fluid-structure interaction between the cytoskeleton and cytosol, and the effects of hierarchical fluid-structure interaction across the cell during freezing.

scholarly journals Numerical Methods for Fluid-Structure Interaction — A Review

2012 ◽  
Vol 12 (2) ◽  
pp. 337-377 ◽  
Author(s):  
Gene Hou ◽  
Jin Wang ◽  
Anita Layton
Keyword(s):  
Numerical Methods ◽  
Fluid Structure Interaction ◽  
Fluid Flows ◽  
Fluid Structure Interactions ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Wide Range ◽  
Recent Developments ◽  
Conforming Meshes ◽  
Incompressible Fluid Flows

AbstractThe interactions between incompressible fluid flows and immersed structures are nonlinear multi-physics phenomena that have applications to a wide range of scientific and engineering disciplines. In this article, we review representative numerical methods based on conforming and non-conforming meshes that are currently available for computing fluid-structure interaction problems, with an emphasis on some of the recent developments in the field. A goal is to categorize the selected methods and assess their accuracy and efficiency. We discuss challenges faced by researchers in this field, and we emphasize the importance of interdisciplinary effort for advancing the study in fluid-structure interactions.

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.

Study and Analysis of the Fluid-Structure Interaction Between Apple and Underwater Shock Wave

2007 ◽  
Author(s):  
Asuka Oda ◽  
Moji Moatamedi ◽  
Shigeru Itoh
Keyword(s):  
Shock Wave ◽  
Apple Juice ◽  
Fluid Structure Interaction ◽  
Water Tank ◽  
Underwater Shock Wave ◽  
Element Analysis ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Exploratory Experiment ◽  
Underwater Shock

Shock wave treatment of an apple can produce a soft apple similar to a sponge containing water. Therefore, without needing to cut and grate apples, apple juice can be easily obtained by squeezing by hand. In a previous result, it was reported that more than 40MPa shock pressure was needed to make a soft apple. From observation for the shock treatment for the apple, an oblique wave was produced from a detonating fuse and the wave reflected at the surface of the apple. The resulting shock wave data was obtained. In the result of further observations, there was the possibility that the wave passing through the apple was attenuated faster than the wave passing through water. In this report, the same method in the previous research was used. Apples, detonating fuse, and electric detonator were set in water tank, with the fuse initiated by electric detonator. In this research, the behavior of shock wave passing through an apple was researched as exploratory experiment for numerical analysis. In the future, we want to attempt to analyze the fluid-structure interaction between the apple and underwater shock wave by using computer finite element analysis.

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