A BIOMECHANICAL APPROACH TO DRAG FORCE AND HYDRODYNAMIC COEFFICIENT ASSESSMENTS

Abstract

A fundamental theoretical analysis for estimation of kinematic and kinetic characteristics of swimmers was developed. The purpose of the study was to present a simple method for data collection, to establish simple formulae for determining the swimmers characteristics and to evaluate the validity and accuracy of the model estimation against the other methods such as; direct measurements; Measurement of Active Drag, and added drag provided by hydrodynamic body. The active drag force was estimated during maximal swimming in front crawl but the method can also be applied for other strokes. The swimmers performed three 10-meter trials with enough rest in between and with zero initial velocity over which average velocity was calculated. By this method the maximum speed of swimmers in 10m swim could also be estimated. The swimmers began to swim from still position after whistling, and stopped swimming at the end of 10m again by whistling, and kept gliding until still position. The time of 10m swim and the glided distance were measured with reasonable precision and then used in the established formulae for determining the velocity, acceleration, and drag force. One of the elite swimmers was requested to perform swimming with different speeds in order to achieve different characteristic curves for proposed model.