Scale Effects on a Tip Rake Propeller Working in Open Water

Abstract

The scale effect on the accuracy of a numerical simulation in ship hydrodynamics represents an important issue of the propeller numerical analysis. To grasp a better understanding on the influence of this effect, an introspection on the performances of an unconventional propeller is proposed in the present study. The paper describes an investigation of the performances of a tip rake propeller recently chosen as benchmark by the International Towing Tank Conference organization (ITTC hereafter). The numerical simulation is carried out by making use of the ISIS-CFD solver, part of the FineTM/Marine package available in the NUMECA suite. The solver is based on the finite volume method to build the spatial discretization of the governing equations. The incompressible unsteady Reynolds Averaged Navier-Stokes Equations (RANSE) are solved in a global approach. Reported solutions are compared with the experimental data provided by Schiffbau-Versuchsanstalt (SVA) Potsdam GmbH to validate the accuracy of the numerical approach. Since for the full scale the experimental data could not be possible, the ITTC’78 extrapolation method-based proposed by the SVA Potsdam has been taken as a basis for comparisons and discussions. A set of remarks will conclude the paper by providing some guidelines for further approaches in terms of the particulars of the numerics that may be further employed in similar studies.

A DES-SST Based Assessment of Hydrodynamic Performances of the Wetted and Cavitating PPTC Propeller

“…Within the above context, the present paper describes a numerical investigation aimed at clarifying the details of the flow around the VP 1304 controllable pitch propeller, known in the naval architecture community as the Potsdam propeller test case (PPTC). The work continues a previous study of the author [34] which was devoted to the assessment of the scale effects on the P1727 (PPTC II) propeller. In the present study, the numerical simulations are performed for both wetted and cavitating regimes for a series of eight different advance ratio coefficients.…”

“…λ is a factor of proportionality, which is recommended to be between 1 and 10. These limits are compatible with the values recommended for boundary layer flows, therefore λ = 10 was chosen [34]. Since free-shear layers are more sensitive to small free-stream values of ω ∞ and larger values of ω are imposed in the free-stream, at least λ = 40 for mixing layers, increasing up to λ = 80 for round jets.…”

Large Flow Separations around a Generic Submarine in Static Drift Motion Resolved by Various Turbulence Closure Models

“…A complete understanding of Reynolds number effects is essential for extrapolating the model-based solutions to full scale. A reliable prediction of the overall hydrodynamic performances should therefore comprise a good understanding of the scale effects at full-scale Reynolds numbers, as previously proved for propellers by the author [2]. Nonetheless, the preponderance of experimental data available for undersea vehicles is limited to model-scale.…”

Cavitation Prediction of Ship Propeller Based on Temperature and Fluid Properties of Water

“…The experimental data and geometries are published on the company's website (www.sva-potsdam.de/pptc). Previous research used the VP1304 model for numerical simulation and validation data, and it was used at the Fourth International Symposium on Marine Propulsors 2015 (SMP'15) [27]. The significant advancement of computer performance has made more numerical simulation possible.…”