The Role of the Hand During Freestyle Swimming

2015 ◽  
Vol 137 (11) ◽  
Author(s):  
Raymond C. Z. Cohen ◽  
Paul W. Cleary ◽  
Bruce R. Mason ◽  
David L. Pease
Keyword(s):  
Fluid Model ◽  
Three Dimensional ◽  
The Body ◽  
Cfd Modeling ◽  
Vortical Structures ◽  
Video Footage ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Computational Fluid Dynamics Cfd ◽  
Lift And Drag

The connections between swimming technique and the fluid dynamical interactions they generate are important for assisting performance improvement. Computational fluid dynamics (CFD) modeling provides a controlled and unobtrusive way for understanding the fundamentals of swimming. A coupled biomechanical–smoothed particle hydrodynamics (SPH) fluid model is used to analyze the thrust and drag generation of a freestyle swimmer. The swimmer model was generated using a three-dimensional laser body scan of the athlete and digitization of multi-angle video footage. Two large distinct peaks in net streamwise thrust are found during the stroke, which coincide with the underwater arm strokes. The hand motions generate vortical structures that travel along the body toward the kicking legs and the hands are shown to produce thrust using both lift and drag. These findings advance understanding of the freestyle stroke and may be used to improve athlete technique.

Smoothed Particle Hydrodynamics into the Fluid Dynamics of Classical Problems

2016 ◽  
Vol 846 ◽  
pp. 73-78 ◽  
Author(s):  
Maziar Gholami Korzani ◽  
S. Galindo Torres ◽  
Alexander Scheuermann ◽  
David J. Williams
Keyword(s):  
Fluid Dynamics ◽  
Analytical Solutions ◽  
Poiseuille Flow ◽  
Smoothed Particle Hydrodynamics ◽  
Slip Boundary Condition ◽  
Sph Method ◽  
Slip Boundary ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Computational Fluid Dynamics Cfd

The study concerns the application of the Smoothed Particle Hydrodynamics (SPH) method within the computational fluid dynamics (CFD). In the present study, some classical problems – the Poiseuille flow, the Hagen-Poiseuille flow, and the Couette flow – with the analytical solutions were investigated to verify a newly developed code of SPH. The code used for solving these problems, is an entirely parallel SPH solver in 3D and has been developed by the authors. Fluid was modelled as a viscous liquid with weak compressibility. The boundary walls were simulated with a special set of fixed boundary particles, and no-slip boundary condition was considered. Computational results were compared to available analytical solutions for transient hydraulic processes. Good agreement is achieved for the whole transient stage of the considered problems until steady state is reached. The results of this study highlight the potential of SPH to tackle a broad range of problems in fluid mechanics.

Smoothed Particle Hydrodynamics Simulations of Whole Blood in Three-Dimensional Shear Flow

2020 ◽  
Vol 17 (10) ◽  
pp. 2050009
Author(s):  
Sisi Tan ◽  
Mingze Xu
Keyword(s):  
Shear Flow ◽  
Smoothed Particle Hydrodynamics ◽  
Whole Blood ◽  
Blood Cells ◽  
White Blood Cells ◽  
Three Dimensional ◽  
Immersed Boundary ◽  
Particle Hydrodynamics ◽  
Sph Model ◽  
Smoothed Particle

Numerical modeling of whole blood still faces great challenges although significant progress has been achieved in recent decades, because of the large differences of physical and geometric properties among blood components, including red blood cells (RBCs), platelets (PLTs) and white blood cells (WBCs). In this work, we develop a three-dimensional (3D) smoothed particle hydrodynamics (SPH) model to study the whole blood in shear flow. The immersed boundary method (IBM) is used to deal with the interaction between the fluid and cells, which provides a possibility to model the RBCs, PLTs and WBCs simultaneously. The deformation of a small capsule, comparable to a PLT in size, is first examined to show the feasibility of SPH model for the PLTs’ behaviors. The motion of a single RBC in shear flow is then studied, and three typical modes, tank-treading, swinging and tumbling motions, are reproduced, which further confirm the reliability of the SPH model. After that, a simulation of the whole blood in shear flow is carried out, in which the margination trend is observed for both PLTs and WBC. This shows the capability of SPH model with IBM for the simulation of whole blood.

scholarly journals Relationship between Spacing Rasio and Stiffness Coefficient by Using Smoothed Particle Hydrodynamics Method to Simulate Water – Solid Interaction

2019 ◽  
Vol 95 ◽  
pp. 02011
Author(s):  
Anisa Wulandari ◽  
R.R Dwinanti Rika ◽  
Jessica Sjah ◽  
Herr Soeryantono
Keyword(s):  
Smoothed Particle Hydrodynamics ◽  
Three Dimensional ◽  
Stiffness Coefficient ◽  
Factors Affecting ◽  
Fluid Behavior ◽  
Grid Approach ◽  
Spacing Ratio ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Smoothed Particle Hydrodynamics Method

Scouring Phenomenon directly occurs on materials due to the motion of water flow and water borne sediments that researchers in the world continue to investigate. Scouring are then continuously developed in Computational Fluid Dynamics (CFD) to be able to estimate scouring effects by analyzing interaction between fluid and solid. Water and solid interaction can be researched by realizing three dimensional numerical modeling (3D) using Smoothed Particle Hydrodynamics Method which is modeling and visualizing fluid behavior with a Lagrangian approach in particle scale (micro scale), a more particle approach realistic than the grid approach. Using this method, the results of each particle can be reviewed either by their property values or visually so that the results are obtained more representatives. One of the factors affecting fluid-solid modeling is spacing ratio between solid particle and fluid particle. To obtain the correct physical results, it is required to consider the influence of spacing ratio and the value of Stiffness Coefficient (Ks) needed.

scholarly journals Research on Duct Flow Field Optimisation of a Robot Vacuum Cleaner

10.5772/50903 ◽  
2011 ◽  
Vol 8 (5) ◽  
pp. 65 ◽  
Author(s):  
Xiao-bo Lai ◽  
Hai-shun Wang ◽  
Hua-shan Liu
Keyword(s):  
Pressure Drop ◽  
Flow Field ◽  
Velocity Vector ◽  
Fluid Model ◽  
Three Dimensional ◽  
Theoretical Modelling ◽  
Duct Flow ◽  
Vacuum Cleaner ◽  
Arbitrary Plane ◽  
Computational Fluid Dynamics Cfd

The duct of a robot vacuum cleaner is the length of the flow channel between the inlet of the rolling brush blower and the outlet of the vacuum blower. To cope with the pressure drop problem of the duct flow field in a robot vacuum cleaner, a method based on Pressure Implicit with Splitting of Operators (PRISO) algorithm is introduced and the optimisation design of the duct flow field is implemented. Firstly, the duct structure in a robot vacuum cleaner is taken as a research object, with the computational fluid dynamics (CFD) theories adopted; a three-dimensional fluid model of the duct is established by means of the FLUENT solver of the CFD software. Secondly, with the k-∊ turbulence model of three-dimensional incompressible fluid considered and the PRISO pressure modification algorithm employed, the flow field numerical simulations inside the duct of the robot vacuum cleaner are carried out. Then, the velocity vector plots on the arbitrary plane of the duct flow field are obtained. Finally, an investigation of the dynamic characteristics of the duct flow field is done and defects of the original duct flow field are analysed, the optimisation of the original flow field has then been conducted. Experimental results show that the duct flow field after optimisation can effectively reduce pressure drop, the feasibility as well as the correctness of the theoretical modelling and optimisation approaches are validated.

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