Verification of the Theory for a Sphere Settling in Fluid With Resistance in Different Ranges by Experiment of π-Testing Design

Based on the Diagram of Resistance Coefficient C_Ｄ versus Re , a resistance term and differential equation were formulated. Its analytical solution proved consistent with the experiment results with the error ranging from 2 %～20 %, while the solution of original differential equation has the error ranging from 136 %～249 %. That experiment was conducted with π-Testing Design. The settling equation of a sphere in fluid proved its generality in the sphere subject to resistance figuring in different ranges.