Experimental Study on Drag Forces of Non-Spherical Objects in Jets

Abstract

Most studies on fluid dynamics only account for spheres in jets. They derive their formula from the Navier-Stokes equation which is only accountable for spheres. However, few can provide a general formula for non-spherical objects since their irregular shape could cause turbulence thus make the accurate measurement difficult. Some of the previous studies investigated the viscous drag on these objects empirically, giving empirical formula using experimental approaches. This study aims to investigate viscous drag on non-spherical objects through stimulating jet conditions using two different experimental set ups, giving experimental results and comment on the empirical formula from previous studies. To begin with, Objects of different masses were tested under fixed wind speeds to measure their stable equilibrium heights, validating theoretical model and formula of drag force in jets with respect to the position inside the jet. Then, another experiment is conducted on non-spherical objects to measure experimental drag force. The experimental result will be compared with the results calculated from the previous empirical formulas, and they will be commented in terms of deviation from the experimental value in terms of accuracy using standard deviation. This research intends to give an insight in to viscous drag on non-spherical bodies using camera-based method and provides a precise measurement and comment onto previous studies.