EFFECTS OF DATA CONDITIONING ON MASS AND DRAG COEFFICIENTS

The effects of data conditioning on the mass and drag coefficients (Cm & Cd) are reviewed by two geometric and one numerical interpretations. Two geometric analyses of data conditioning proposed by Dean demonstrate that when the Dean eccentricity parameter E equals unity, the data are equally well-conditioned for determining Cm & Cd. For simple harmonic data, the Dean eccentricity parameter may be shown to be proportional to the Keulegan-Carpenter parameter, K; ie., E=√3K/2π2. When E=1.0, then K≈11.40 and the Dean error ellipse is a circle with zero eccentricity. The matrix condition number of the 2×2 matrix used to determine Cm & Cd in a best least-squares sense becomes unity when K≈13.16 and E≈1.15. Two sets of experimental data are compared with the two geometric and one numerical analyses.