Computational Analysis of Marine-Propeller Performance Using Transition-Sensitive Turbulence Modeling

Abstract

<jats:p>Almost all computational fluid dynamics (CFD) simulations of flow around marine propellers use turbulence models that are only well suited for fully turbulent flows, which in some cases may lead to accuracy degradation in the prediction of propeller performance characteristics. The discrepancy between computed thrust and torque and corresponding experimental data increases with increasing propeller load. This is due in part to the fact that a large laminar flow region is found to exist and turbulence transition takes place on propeller blades of model scale and/or under high-load conditions. In these cases, it may be necessary to consider boundary-layer transition to obtain accurate results from CFD simulations. The objective of this work is to perform simulations of a marine propeller using a transition-sensitive turbulence model to better resolve the propeller flow characteristics. Fully turbulent flow simulations are also performed for comparison purposes at various propeller load conditions. Computational results are analyzed and compared with water-tunnel and open-water experimental data. It is found that the applied transition-sensitive turbulence model is better able to resolve blade-surface stresses, flow separations, and tip-vortex originations, and, consequently, improve the prediction accuracy in propeller performance, especially under high-load conditions. Furthermore, solutions obtained using the transition-sensitive turbulence model show tip-vortex flows of higher strength, whereas results by the standard k-ω SST turbulence model indicate excessive dissipation of the vortex core.</jats:p>

Numerical Study on the Wake Evolution of Contra-Rotating Propeller in Propeller Open Water and Self-Propulsion Conditions

“…Felli et al [9] measured wake field and pressure fluctuation downstream of the propeller to investigate the correlation of the velocity and pressure signal. On the other hand, numerical simulations using computational fluid dynamics (CFD) based on Reynolds averaged Navier−Stokes (RANS) equations were performed by Rhee and Joshi [10], Di Felice et al [11], Arikan et al [12], Wang and Walters [13], Baek et al [14], and Kinaci and Gokce [15] to study the characteristics of propeller wake.…”

Influence of drift angle on the computation of hull–propeller–rudder interaction

“…The numerical simulation assumed a fully turbulent boundary layer, while the flow over the experimental rudder was tripped from laminar to turbulent flow at a distance of 5.7% from the leading edge of the chord on both sides of the rudder using turbulence strips. This problem has been addressed by Wang and Walters (2012) who carried out studies to demonstrate the capability of transition sensitive turbulence models for three dimension turbulent flows around complex geometries to determine the relative importance of resolving the boundary layer transitional effect. According to Wang and Walters (2012) the SST is poorer at resolving the tip vortices and showed large discrepancies in propeller forces with increased propeller loads compared to transition sensitive models and this will have a significant effect on the forces of a rudder placed downstream of the propeller.…”

“…This problem has been addressed by Wang and Walters (2012) who carried out studies to demonstrate the capability of transition sensitive turbulence models for three dimension turbulent flows around complex geometries to determine the relative importance of resolving the boundary layer transitional effect. According to Wang and Walters (2012) the SST is poorer at resolving the tip vortices and showed large discrepancies in propeller forces with increased propeller loads compared to transition sensitive models and this will have a significant effect on the forces of a rudder placed downstream of the propeller. It should also be noted however that assumptions were made by neglecting the gap between the rudder and the wind tunnel floor and also the support structure for the propeller which probably have effects on the drag force of the rudder.…”

“…Investigations by Simonsen and Stern, (2005) and Phillips et al, (2009) highlight the difficulties in the prediction of propeller torque and rudder forces with large uncertainties and comparison errors between calculated and experimental result unless significantly larger meshes are used. Wang and Walters (2012) indicated values in excess of 22M to resolve propeller forces, whilst Date and Turnock (2002) indicates values of 5-20M cells to fully resolve the ruder forces. However, a good level of understanding of the global forces required for rudder and propeller forces during manoeuvring may be obtained with this level of mesh resolution.…”

3D CFD Simulation and Experimental Validation of Small APC Slow Flyer Propeller Blade

“…In addition, Wang et al [8] analysed marine propeller performance using transition sensitive turbulence modelling for CFD analysis. The analysis provides the method to minimize the discrepancy between CFD and experimental results by including transitional analysis.…”