Experimental and Numerical Investigations About Hydraulic Top Bracings and Its Influence on Engine and Vessels Superstructure Vibrations

Top bracings are widely used to control vibration of main engines onboard ships. Currently two types of top bracings are used: hydraulic top bracings and mechanical top bracings with a friction connection. Main advantages of hydraulic top bracing are their improved ability to compensate relative deflections between the engine and the ship and that their dynamic characteristic can be controlled by different settings. Compared to conventional mechanical top bracings MAN-ES hydraulic top bracings have two basic settings that can be controlled by engine speed: the standard active setting and the passive setting. While in the active setting the hydraulic top bracing acts like a spring with a certain amount of stiffness, similar in its behavior to the mechanical type, in the passive setting it acts like a weak damper.To get more insight into the dynamic characteristics of hydraulic top bracings and their influence on the engine and structural vibrations, MAN-ES conducted several measurements on several ships. Based on the measurements, the working principle was, and their stiffness and damping properties were studied. Also, the condition with the top bracings being drained from oil and the correlation between the different top bracing settings and the vibrations response of the superstructure was investigated.In a joint project, DNVGL and MAN-ES aimed at correlating the measurement results by the simulation findings [1]. Based on a validated simulation model it was then even possible to investigate several more different nonstandard configurations and settings by additional simulations.

Language

  • English

Media Info

  • Media Type: Web
  • Features: References;
  • Pagination: pp 387-407
  • Monograph Title: Practical Design of Ships and Other Floating Structures: Proceedings of the 14th International Symposium, PRADS 2019, September 22-26, 2019, Yokohama, Japan- Volume II

Subject/Index Terms

Filing Info

  • Accession Number: 01928411
  • Record Type: Publication
  • ISBN: 9789811546716
  • Files: TRIS
  • Created Date: Aug 23 2024 4:53PM