Estimation of the time of immersion/emersion of diving buoys with approximate model

A.V. Dologlonyan, A.K. Sukhov

Institute of Natural and Technical Systems, Russian Federation, Sevastopol, Lenin St., 28

E-mail: dologlonyan@gmail.com

DOI: 10.33075/2220-5861-2018-4-27-32

UDC 681.51

Abstract:

   Speed of immersion/emersion of a diving buoy is of great importance for quality of results of profile measurements. Speed of the diving buoy is determined by its geometrical (the volume, the ratio of total length and diameter) and physical (the weight, the resistance coefficient) parameters.

      The process of immersion / emersion is divided into two phases:

1) a motion phase in the course of bleeding / filling of the external receiver;

2) a drift phase in the vertical plane.

      The first phase and the beginning of the second one determine the maximum possible speed which, in its turn, effects the average motion speed of the drifter and, respectively the time of immersion/emersion.

     The purpose of this work is to find approximate solution constructed in mathematical model and to analyze it later for assessment of the time of immersion / emersion of diving buoys for routine and energy saving modes.

     It has been found that the distance covered by the submersible (S) in the first phase is short – about 10 … 200 m depending on the pumpage of the system of buoyancy change. Density at such small distances changes slightly, therefore, the density dependence on coordinate can be neglected and the mathematical model can be simplified.

      The precise model studies showed that changes of speed in the second phase of immersion / emersion can be considered to be linear, and for assessment of time and average speed it is enough to determine maximum speed reached at the beginning of the second phase.

      The approximate mathematical model of the submersible motion proposed in the work and its solution describing the first phase of emersion and the beginning of the second one has an admissible error (no more than 3%) of determination of parameters of immersion / emersion processes at coordinate changing  not more than 200 … 300 m, and can be used in practical calculations of both maximal and average speeds of S emersion in the routine and energy saving mode as well as the time of immersion / emersion  reducing the time of their realization essentially.

Keywords: diving buoy, equation of the movement, undersea vehicle, emersion time.

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