Ship Form Optimization & Lines​

The main goal of form optimization studies is to reduce the ship’s resistance to the lowest possible value.

One of the structural elements that most affects resistance is the bulb and the ship hull surface immediately behind it. The ship form prepared parametrically is examined in terms of resistance using the CFD method with different parameters. The resistance value corresponding to the form with the lowest value is accepted as the original result for main machine power calculation.

We carry out form optimization studies, in addition to current CAD software, with DELFTSHIP Modeler, Siemens SOLID EDGE Pro, Siemens STAR CCM+ and other equivalent powerful softwares, which are among the most popular in the market.

In form optimization studies, we achieve extremely smooth lines on the ship’s outer hull with a single surface method instead of the multiple patch method traditionally used, thus achieving high quality in both manufacturing and finite element analysis calculations.

The change in the bulb region is clearly seen in the below figure in an example study on the resistance value.

ship theoretical calculations

Ship conceptual design focuses on determining the general characteristics and functions of the ship. At this stage, basic features such as the dimensions, type, function, payload capacity, speed, and range of the ship are determined. In addition, initial ideas are developed about the general layout, main machinery and systems of the ship.

The design process, which starts with the optimization of the ship’s form, covers all original calculations such as ship power analysis, initial intact & damage stability, longitudinal strength SF & BM and, continues with structural stress analysis of ships, vibration and noise analysis, modal analyses in dry and wet environments, in later stages.

Our ship theoretical calculations cover the following :

Preliminary and final intact & damaged stability (Probabilistic and Deterministic)
Longitudinal strength – Shear forces and Bending Moments
Speed & Power calculations
Freeboard and Tonnage
Deadweight scale
Ship hydrostatics
Tank soundings
Launching (40+ ships)

By performing stability and longitudinal strength calculations in sync with ship structural stress analysis, the possibility of a structural break in the ship due to the load taken by the ship is prevented. The accuracy and precision of structural stress analysis are closely related to the dimensions of the cells in the mesh system used in the calculations. The smaller cell size means the higher accuracy of the result.

Ship theoretical studies


We carry out computational fluid dynamics (CFD) and finite element analysis (FEA) studies with Siemens NASTRAN, Siemens STAR CCM+ and other equivalent powerful softwares, which is an indispensable program for research centers. We use Siemens SOLID EDGE Pro to model the 3D ship structural elements used in these calculations.

The sensitivity level of the mesh structure of the hull in computational fluid dynamics and finite element analysis has a great effect on the calculation results. Therefore, we prepare the mesh system at a higher fineness than the standard mesh size. In this method, the calculation time is extended significantly, but since a satisfactory level is reached in the results, we do not compromise on the accuracy of the convergence value.

Siemens NASTRAN’s mesh generation capabilities are very advanced, so it is more reliable than other softwares in this regard.

As is known, NASTRAN is the ancestor of FEA softwares, it has a 10-year process difference with its closest competitor, it is the first to enter the market, and it is still being used effectively by NASA

Our Computational Fluid Daynamics & Finite Element Analysis calculations covers the following:

Hydrodynamic analysis
Ship vibration and noise analysis
Structural stress analysis
Free-free modal analysis
Pre-stressed modal analysis in water

Nastran-generated mesh Aft-Fore Body

3D model prepared in Siemens Solid Edge for pre-stressed modal analysis in water

Computational Fluid Dynamics

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