Construction of drag force measuring system to characterize the hydrodynamics properties of swimsuit fabrics

In this study, a system was designed and constructed in order to measure the drag force acting on the swimmer simulator. This system must be able to obtain the drag force for a range of swimsuit fabrics to characterize the hydrodynamic properties of swimsuit fabric. In this system, a DC motor was used as the propelling unit; also a voltmeter and an ammeter were applied to measure the input power of motor. To find the relationship between input powers and drag force, calibration was done. The simulator was made from wood in two different sizes. The samples of fabrics were prepared from three kinds of weft knitted fabrics, which are common in production of swimsuits, and were knitted from polyamide6 (nylon), polyamide6-elastan (nylon-lycra) and polyester. The statistical analysis of results show the importance of fabric surface properties and swimsuit design on swimmer’s performance, so clothing engineering and technical clothing design can play a key role in sport engineering.