Research and development to create high-performance propellers

In order to achieve the optimum propeller design, it is necessary to predict then verify the propeller’s performance.
Nakashima carries out CFD-based simulation to predict each propeller’s performance and conducts model tests to verify the prediction test results.
For high-performance propellers, three performance factors are required: Efficiency, strength, and anti-cavitation.
A propeller that satisfies all three can be considered to be the “most suitable propeller” for the specific ship.

These factors are contradictory. If a propeller is designed in the pursuit of high efficiency only, the blade becomes too thin and the strength too low. Under such conditions, excessive cavitation occurs that may cause vibration, damaging the vessel's body or rudder.
Therefore, it is extremely important to design a propeller that achieves a good balance between the three performance factors of efficiency, strength, and anti-cavitation. Nakashima Propeller verifies each of these factors by performing simulations.

Overwhelming number of cores – CFD-based simulation

Nakashima visualizes the flow by CFD boasting an overwhelming number of cores, then performs analysis.
Use of large-scale CFD enables simulations of more complex, detailed phenomena in a short time.
It also allows estimation of the propeller’s performance, cavitation simulation, and calculation of erosion risk.

Structural soundness evaluation – FEM

Evaluation of the strength of propeller blades is very important because they are used in complex hydrodynamic environments. A structural evaluation process in the early stages of design is also necessary to secure the structural performance of each piece of propulsion equipment.
Nakashima therefore evaluates the soundness of each product by effectively utilizing structural analysis technology.

Research and development leading to new designs

Nakashima improves design accuracy by reflecting empirical values accumulated over many years and repeatedly carrying out CFD-based simulations and model testing, which serve as the backbone of propeller design, and by reapplying the results to regular design.

In addition to existing designs, Nakashima also carries out these research and development activities and develops various new types of propellers such as NHV and Tip Rake.

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  NHV Type
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  Conventional Type