Pressure impulse theory for a slamming wave on a vertical circular cylinder

A pressure impulse model is presented for wave impact on vertical circular cylinders. Pressure impulse is the time integral of the pressure during an impact of short time scale. The model is derived for a simplistic geometry and has relative impact height, crest length and cylinder radius as effective variables. The last parameter, the maximum angle of impact, is free and can be calibrated to yield the right force impulse. A progression of simpler pressure impulse models are derived in terms of a three-dimensional box generalization of the two-dimensional wall model and an axisymmetric model for vertical cylinders. The dependence on the model parameters is investigated in the simpler models and linked to the behaviour of the three-dimensional cylinder model. The model is next validated against numerical results for a wave impact for a phase- and direction-focused wave group. The maximum impact angle is determined by calibration against the force impulse. A good match of the pressure impulse fields is found. Further comparison to the force impulse of two common models in marine engineering reveals improved consistency for the present model. The model is found to provide a promising representation of the pressure impulse field, based on a limited number of input parameters. Its further validation and potential as a robust tool in force and response prediction is discussed.

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Two and Three-Dimensional Pressure-Impulse Models of Wave Impact on Structures

Coastal Engineering 1998 ◽

10.1061/9780784404119.111 ◽

1999 ◽

Author(s):

Deborah J. Wood ◽

D. Howell Peregrine

Keyword(s):

Three Dimensional ◽

Wave Impact ◽

Pressure Impulse

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Optical properties of three-dimensional woodpile photonic crystals composed of circular cylinders with planar defect structures

Applied Optics ◽

10.1364/ao.50.006657 ◽

2011 ◽

Vol 50 (36) ◽

pp. 6657

Author(s):

Shih-Hsuan Chung ◽

Jaw-Yen Yang

Keyword(s):

Optical Properties ◽

Photonic Crystals ◽

Three Dimensional ◽

Planar Defect ◽

Circular Cylinders ◽

Defect Structures

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Three-Dimensional Fixed-Time Cooperative Guidance Law With Impact Angle Constraint and Prespecified Impact Time

IEEE Access ◽

10.1109/access.2021.3057428 ◽

2021 ◽

Vol 9 ◽

pp. 29755-29763

Author(s):

Mu Lin ◽

Xiangjun Ding ◽

Chunyan Wang ◽

Li Liang ◽

Jianan Wang

Keyword(s):

Three Dimensional ◽

Fixed Time ◽

Impact Angle ◽

Impact Time ◽

Guidance Law ◽

Cooperative Guidance ◽

Impact Angle Constraint

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Quaternion Based Three-Dimensional Impact Angle Control Guidance Law

IEEE Transactions on Aerospace and Electronic Systems ◽

10.1109/taes.2021.3058398 ◽

2021 ◽

pp. 1-1

Author(s):

Jeong-Hun Kim ◽

Sang-Sup Park ◽

Kuk-Kwon Park ◽

Chang-Kyung Ryoo

Keyword(s):

Three Dimensional ◽

Impact Angle ◽

Guidance Law

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A flexible framework for sequential estimation of model parameters in computational hemodynamics

Advanced Modeling and Simulation in Engineering Sciences ◽

10.1186/s40323-020-00186-x ◽

2020 ◽

Vol 7 (1) ◽

Author(s):

Christopher J. Arthurs ◽

Nan Xiao ◽

Philippe Moireau ◽

Tobias Schaeffter ◽

C. Alberto Figueroa

Keyword(s):

Unscented Kalman Filter ◽

Three Dimensional ◽

Synthetic Data ◽

Sequential Estimation ◽

Wall Material ◽

Patient Specific ◽

Model Parameters ◽

Computational Framework ◽

Lumped Parameter ◽

Estimation Of Model Parameters

AbstractA major challenge in constructing three dimensional patient specific hemodynamic models is the calibration of model parameters to match patient data on flow, pressure, wall motion, etc. acquired in the clinic. Current workflows are manual and time-consuming. This work presents a flexible computational framework for model parameter estimation in cardiovascular flows that relies on the following fundamental contributions. (i) A Reduced-Order Unscented Kalman Filter (ROUKF) model for data assimilation for wall material and simple lumped parameter network (LPN) boundary condition model parameters. (ii) A constrained least squares augmentation (ROUKF-CLS) for more complex LPNs. (iii) A “Netlist” implementation, supporting easy filtering of parameters in such complex LPNs. The ROUKF algorithm is demonstrated using non-invasive patient-specific data on anatomy, flow and pressure from a healthy volunteer. The ROUKF-CLS algorithm is demonstrated using synthetic data on a coronary LPN. The methods described in this paper have been implemented as part of the CRIMSON hemodynamics software package.

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Wave Impact on a Wall Using Pressure-Impulse Theory. I: Trapped Air

Journal of Waterway Port Coastal and Ocean Engineering ◽

10.1061/(asce)0733-950x(2000)126:4(182) ◽

2000 ◽

Vol 126 (4) ◽

pp. 182-190 ◽

Cited By ~ 45

Author(s):

Deborah J. Wood ◽

D. Howell Peregrine ◽

Tom Bruce

Keyword(s):

Wave Impact ◽

Pressure Impulse ◽

Trapped Air

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A faster escape does not enhance survival in zebrafish larvae

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2017.0359 ◽

2017 ◽

Vol 284 (1852) ◽

pp. 20170359 ◽

Cited By ~ 16

Author(s):

Arjun Nair ◽

Christy Nguyen ◽

Matthew J. McHenry

Keyword(s):

High Speed ◽

Larval Fish ◽

Body Position ◽

Three Dimensional ◽

Limited Range ◽

The Body ◽

Model Parameters ◽

Fish Prey ◽

Zebrafish Larvae ◽

Fish Predators

An escape response is a rapid manoeuvre used by prey to evade predators. Performing this manoeuvre at greater speed, in a favourable direction, or from a longer distance have been hypothesized to enhance the survival of prey, but these ideas are difficult to test experimentally. We examined how prey survival depends on escape kinematics through a novel combination of experimentation and mathematical modelling. This approach focused on zebrafish ( Danio rerio ) larvae under predation by adults and juveniles of the same species. High-speed three-dimensional kinematics were used to track the body position of prey and predator and to determine the probability of behavioural actions by both fish. These measurements provided the basis for an agent-based probabilistic model that simulated the trajectories of the animals. Predictions of survivorship by this model were found by Monte Carlo simulations to agree with our observations and we examined how these predictions varied by changing individual model parameters. Contrary to expectation, we found that survival may not be improved by increasing the speed or altering the direction of the escape. Rather, zebrafish larvae operate with sufficiently high locomotor performance due to the relatively slow approach and limited range of suction feeding by fish predators. We did find that survival was enhanced when prey responded from a greater distance. This is an ability that depends on the capacity of the visual and lateral line systems to detect a looming threat. Therefore, performance in sensing, and not locomotion, is decisive for improving the survival of larval fish prey. These results offer a framework for understanding the evolution of predator–prey strategy that may inform prey survival in a broad diversity of animals.

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