32_meters_project

NEW PROJECT | 32 meters Twin Screw Motor Yacht

NOISE TARGETS TO BE ACHIEVED:

COMFORT CLASS LEVELS | DNV | GL

DNV_table_1
DNV_table_2

SILENT LINE SCOPE OF SUPPLY:

To achieve the comfort class 1 noise and vibration levels as specified by DNV, Silent Line will carry out the following noise and vibration studies:

Preliminary Insulation Plan:

Preliminary_Insulation_Plan

This inhouse program is used to specify in detail which materials to use in each cabin or room. Detailed information is given for:

  • Hull insulation,
  • Deck insulation,
  • Bulkhead insulation,
  • Flooring,
  • Partition walls
  • Etc.

The weight per cabin and the overall weight throughout the Yacht is given which is important information for the Designers and Interior Designers.

Upon approval of the client, we will proceed with detailed engineering-based drawings per cabin or room as shown below.

Detailed Insulation Drawings:

Detailed_Insulation_Drawings

Detailed drawings similar as shown above are given for:

  • Hull sides,
  • Deck structure,
  • Bulkheads,
  • Flooring,
  • Partition walls,
  • Sound deadening and thermal insulation,
  • Etc.

Finite Element Analysis (F.E.A):

Finite_Element_Analysis
Finite_Element_Analysis_2

Example of FEA computer simulation model.

Finite Element Analysis is foreseen for the following structures:

  • Stern structure
  • Engine room foundations
  • Engine room bulkheads
  • Main bulkheads
  • Deck structures

The outcome of the FEA model(s) is studied and compared versus the main disturbing frequencies of the main sound sources to avoid annoying vibrations and resonance.

Predicted Noise Levels by Computer Simulation:

Silent Line developed over the many years and inhouse computer simulation model(s) to predict noise levels in each cabin or room during free sailing conditions and anchor condition. Main data which is used in our computer models are:

  • Structural data,
  • Data on main sound sources,
  • Distance between main sound sources and the center of the cabin | room,
  • Data abstracted from our preliminary insulation plan,
  • Data from each cabin or room for room acoustic calculations,
  • More.

The outcome of the prediction is shown below:

Predicted noise levels per main sound path.

Predicted noise levels per main sound path.

Predicted_noise_levels_per_main_sound_path

Overall predicted noise levels Lp and A corrected noise levels for the human ear. Also, the overall predicted noise level and corresponding noise rating curve (NRC) number.

Octave_band

Pending on the dimensions of the cabin or room, important room acoustic parameters are calculated such as room absorption, reverberation time and critical distance. This is pending on the volume of the cabin or room, carpet present yes or no, sound absorbing ceiling yes or no, number of beds etc.

Additional studies performed by Silent Line:

  • HVAC related studies,
  • Elastic mounting systems for main diesel engines, gearbox, generator sets and secondary machinery.
  • Propulsion propeller related studies,
Propulsion_Propellers
  • Hydraulic noise,
  • Stabilizer noise,
  • Cabin-to-cabin noise,
  • More

Aim for this project:

The client requires a very comfortable Yacht during cruising and anchor condition. We therefor set the targets like DNV comfort class 1 which is very comfortable and quiet.

Silent Line has a reputation achieving extremely low noise and vibration levels.