مدلهاي رياضي پيشنهادي براي اندازه گيري غيرمستقيم نيروي مقاوم آب

Mathematical Model for Indirect Measurements of Water Resistance

A fundamental theoretical analysis to estimate the kinematic and kinetic characteristics of swimmers was developed. The purpose of the study was to present a simple method for data collection, to establish a simple formula to determine the swimmersʹ characteristics and to evaluate the validity and accuracy of this model of estimation against other methods such as direct measurements, MAD, and added drag provided by hydrodynamic body. The active drag force was estimated during maximal swimmig in front crawl but the method can also be applied for other strokes. The swimmers performed three 10 meter trial with enough rest in between and with initial velocity of zero on which average velocity was calculated. In this method, the maximum speed of swimmers in 10m-trial was estimated.After whistling the swimmers began swimming from the still position and stopped swimming at the end of the 10m-trial again after whistling and kept gliding to still position. The time of 10m-trial and the glided distance were measured with reasonable precision and was used in the mentioned formula to determine the velocity, acceleration, and active drag force of the swimmers. One of the elite swimmers was requested to perform swimming with different speeds to achieve different characteristic curves for the model. The results obtained agreed well with the results by other researches of complicated and expensive systems.