Article 2

Study Overview

• Title: Computational Fluid Dynamics Study of Swimmer’s Hand Velocity, Orientation, and Shape

• Published in BioMed Research International, 2013.

• Authors: Milda Bilinauskaite et al.

• Focus: Investigating hydrodynamic properties of various swimmers' hand models during freestyle swimming.

Objectives

• Determine hydrodynamic characteristics influenced by:

  • Angle of attack

  • Sweepback angle

  • Shape and velocity of swimmer’s hand

• Simulate underwater strokes of freestyle swimming using 3D hand models.

Methodology

• Models Used: Four 3D digitized hand models configured differently (e.g., fingers spread, thumb adducted/abducted).

• Simulation Tool: ANSYS FLUENT for fluid dynamics analysis.

• Parameters Measured:

  • Drag force and drag coefficients during different swim phases (glide, pull, push).

  • Pressure distribution around the hands at varying flow velocities.

Key Findings

• Drag Properties:

  • Varied based on hand shape, position, and orientation during swimming phases.

  • Closed fingers generated highest drag forces and drag coefficients.

• Influence of Orientation:

  • Effective hand optimization enhances propulsion during crucial phases of swimming strokes.

• Velocity Impact:

  • Increased flow velocity affects drag coefficients and forces across different phases.

Hand Models Characteristics

• Models:

  • Hadducted: Thumb adducted.

  • Habducted: Thumb abducted.

  • Hspread: All fingers spread.

  • Hadducted,spread: Thumb adducted with fingers spread.

Results Summary

• Pressure Measurements:

  • Significant variations in pressure forces distributed across hand models based on orientations.

• Operational Variances:

  • The drag force and drag coefficient showed consistency with previous CFD studies while varying with adjustments in hand orientation.

Implications

• Findings provide insights on optimizing swimmer performance by adjusting hand shapes and strokes for improved efficiency in water.

• Suggested swimmers focus on optimizing hand areas during propulsion phases to increase speed and reduce drag.

Study Overview

Title: Computational Fluid Dynamics Study of Swimmer’s Hand Velocity, Orientation, and ShapePublished in: BioMed Research International, 2013.Authors: Milda Bilinauskaite et al.

Focus

This study investigates the hydrodynamic properties of various swimmers' hand models while they perform freestyle swimming. It aims to analyze how different factors such as hand shape, velocity, angle, and sweepback orientation affect swimming efficiency and performance.

Objectives

The primary objectives of this study are to:

• Determine the hydrodynamic characteristics that are influenced by parameters such as:

  • Angle of attack

  • Sweepback angle

  • Shape and velocity of the swimmer’s hand

• Simulate the underwater strokes of freestyle swimming using advanced 3D hand models to provide insights into optimal hand positioning.

Methodology

Models Used:Four distinct 3D digitized hand models were developed and tested, each configured differently to reflect realistic swimmer hand positions:

• Hadducted: Thumb adducted, mimicking a more traditional swimming hand position.

• Habducted: Thumb abducted, promoting a more open-handed stroke.

• Hspread: All fingers spread out, simulating maximum surface area.

• Hadducted,spread: Thumb adducted with fingers spread; merging qualities of both for performance optimization.

Simulation Tool:The study utilized ANSYS FLUENT, a sophisticated computational fluid dynamics tool, to conduct the fluid dynamics analysis of the swimmer's hands in motion across various speeds.

Parameters Measured:

• Drag force and drag coefficients during various swim phases, specifically in glide, pull, and push phases of the stroke.

• Pressure distribution encountered around the hands at different flow velocities to observe how shape and orientation impact swim efficiency.

Key Findings

Drag Properties:The drag characteristics varied significantly based on the shape, position, and orientation of the hands during different swimming phases. The study revealed:

• Closed fingers generated the highest drag forces and drag coefficients, indicating reduced efficiency.

Influence of Orientation:Results indicated that effective optimization of hand positioning enhances propulsion, particularly during crucial phases of swimming strokes, underscoring the role of hydrodynamics in competitive swimming.

Velocity Impact:Higher flow velocities resulted in increased drag coefficients and forces observed across different swimming phases, showing a direct correlation between speed and drag experienced by swimmers.

Hand Model Characteristics

The performances of the four hand models were analyzed, leading to insights about the best hand shapes for swimmers to adopt in different scenarios to minimize drag and maximize propulsion.

Results Summary

Pressure Measurements:Significant variations in pressure forces were observed based on hand model orientations, reflecting the importance of hand positioning on hydrodynamic efficiency.

Operational Variances:The drag force and drag coefficient observed in the study were consistent with previous CFD studies, confirming the reliability of the simulation results while noting variances induced by adjustments in hand orientation.

Implications

The findings from this study provide critical insights into optimizing swimmer performance through methodological adjustments to hand shapes and swimming strokes, ultimately improving efficiency and speed in water. Swimmers are encouraged to focus on maximizing hand areas during the propulsion phases of their strokes to enhance speed and minimize the drag experienced against water resistance.

This detailed examination of swimmer hand dynamics serves as a valuable resource for coaches and athletes aiming to refine their competitive techniques in the sport of swimming.