Case study


Resistance and seakeeping

Customer: GHENOVA
Scope of work:

  • Setting up the numerical model for two initial hull forms:

o Hydroconic hull
o Faired hull

  • Initial analysis with potential code
  • Running a viscous code simulation in the desired condition
  • Analysis of ship resistance for both configurations
  • Propulsion configuration analysis for both cases (Pulling vs Pushing thrusters)
  • Optimization of the best performing solution:

o Third hull geometry proposed

  • Seakeeping calculation for the three hulls

o Natural frequencies detection (RAOs)
o Movements, velocities and accelerations under same wave spectrum

This set of calculations helped in the decision between two different concepts of vessel for the same operation.
Loading condition and speed were considered equal for the two initial geometries; both pulling and pushing thrusters were considered for each hull.
Differences over 20% were found between the needed effective power, reaching 32% power savings when comparing best and worst propulsion combination.
A third geometry was performed, including improvements derived from the reduction of shoulders, modified bulbous bow, a finer entry angle… that reduced hull resistance.
Response Amplitude Operators (RAOs) were calculated for each of the three geometries, in order to compare natural frequencies among them.
A Pierson-Moskowitz wave spectrum was simulated in order to compare movements and accelerations.