Controlled Floater for Marine Pipeline Towing

A developer of innovative equipment designed a system to simplify the towing and laying down of marine pipelines in shallow water fields. EnginSoft was commissioned to verify the conceptual validity of the proposed system and to identify the control characteristics (mechanisms and pneumatic components) which return a prompt response and adequate stability. In order to reduce the towing force, the pipeline residual weight is reduced by applying both standard floaters that apply constant buoyancy and controlled floaters that can adjust the buoyancy according to the pipe depth.

How Numerical Simulation was used in this Project

The numerical simulation of this design involved:

  • the creation of a lumped model of a short branch of pipeline using multi-body simulation technology
  • the calibration of stiffness and damping coefficients to match the dynamical behavior of an identical FEM structure
  • the implementation of the standard and controlled floaters. In particular, the controlled or active ones were reproduced through the non-linear differential equations describing the pneumatics and fluid flows
  • to increase the reliability of the final findings, some parameters are calibrated to match the corresponding available experimental measurements

Design of Experiments techniques were used to investigate the response of the controlled system as the design characteristics of the active floaters are adjusted.

The Value that Numerical Simulation brought to this Project

The execution of a parametric experiment that is significant would require a reasonably long piece of pipeline, a dedicated water field and very expensive equipment making the entire project impractical. This is why a simulation approach to testing the concept was imperative. Through multiple simulations we were able to deeply investigate the concept proposed by the customer in a short time and with good reliability.

This project was made possible by exploiting EnginSoft’s multiple competences. This application required the integration of different areas of science into a single model including pneumatics, hydraulics, control science, structural dynamics and multi-body dynamics.

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