Numerical simulation and experiments of a probe descending in the sea

A numerical model, based on Reynolds equations, was developed to estimate the drag coefficient of a probe. The relation of the displacement of the probe and time was obtained applying the drag coefficients to equations governing the motion of the probe. Experiments were conducted for verification of the calculations. To count in the influence of probe's weight and seawater's density, numerical analysis were carried out. Results indicate both the change of probe's weight due to wire releasing and the difference of density of the different sea area have accumulated influence on the trace of probe and should not be neglected.