Drag coefficients at low Reynolds numbers for flow past immersed bodies

This is the authors' abstract. We don't add key points for this paper.

Drag coefficients were determined at low Reynolds numbers for cylinders (0.1 ⩽ Re ⩽ 1.0) and flat plates (0.05 ⩽ Re ⩽ 2.0) moving through a viscous medium. The drag coefficient was calculated from the force required to move the immersed body through the fluid, and preliminary work on spheres was used to calibrate the apparatus. For all bodies studied the drag coefficient was inversely proportional to the Reynolds number. The data were analyzed by a least‐squares method to obtain the relationship between drag coefficient and Reynolds number. The diameter of the tank containing the viscous fluid had a very definite effect upon the drag coefficient of the various cylinders and flat plates studied. In the range of D T / D (tank diameter/cylinder diameter) studied the relationships recommended by White involving the wall effect and the end correction agree with experimental data for values of L/D (cylinder length/cylinder diameter) greater than 16. At L/D ratios less than this drag coefficients are lower than those predicted by White's equations, and the experimental curves are recommended for these ratios. For flat plates in perpendicular flow no effect of the W/L (plate width/plate length) was detected in the range studied. The tank diameter however had a considerable effect, and a curve is proposed to predict drag coefficients for flat plates in perpendicular flow in the range of experimental conditions studied.