Prototyping of the experimental lifting parachute system

Abstract

Aquatic accidents and incidents due to the hydro-meteorological conditions or to the carelessness of the crew (that can generate failures and collisions between ships), the research of the wrecks and of the lifting of various archaeological, speleological, ecological, geological underwater objects, require the usage of the lifting parachute that represents an extremely useful equipment in these situations.The paper presents the prototyping of the dispensable and executable system including the description of the working environment represented by the fluid medium which can be used as a basis for formulating the requirements imposed for: i) product development (type-dimensions, engineering characteristics, raw material, maximum working depth, object weight flushed), and ii) operation in blue water (open sea where there are no visual reference points to determine the positioning in the water column, and where depth monitoring and strict buoyancy control are needed).From a mathematical point of view, it was considered that, in a marine or oceanic wave, as the depth increases, the circular movement of the fluid particles on the surface transforms and their movement could be described by a set of hyperbolic differential equations.The values of the total force necessary to raise the "wreck" to the surface were determined as a function of the: i) weight of the outside and inside deposits, ii) adhesion force on the bottom of the water, iii) theoretical lift capacity and actual lift capacity. It was demonstrated that for a parachute of a certain shape, with dimensions of 55cm x 55 cm, at a pressure of 8 bar, the maximum weight that can be lifted to the surface is 15,000 kgf. In addition, the following specific coefficients for the aquatic systems design were considered: coefficient of floating area: 0.84; block coefficient: 0.652; belt convergence coefficient: 1.03, etc.The system thus developed was tested with the help of a specialized software, based on the following working assumptions: the medium is continuous, so the mass distribution is continuous in the analysed volume; the infinitesimal internal forces in the environment are considered average statistical values of the interaction forces between the constituent elements; the environment is loaded with concentrated forces Fi and distributed loads pi. These input data enabled to evidence the deformations under the effect of dynamic pressure, Von Misses nodal values, the distribution of displacement vectors and errors. The same set of input data will be used for testing the system under real conditions of usage.

Keywords: mathematical modeling, numerical analysis, structural parameters, lifting parachutes, environmental protection.

DOI: 10.54941/ahfe1004306