A Hybrid Viscous/Potential Flow Method for the Prediction of the Wetted and Cavitating Performance of Ducted Propellers

2015 ◽  
Author(s):  
Spyros A. Kinnas ◽  
Chan-Hoo Jeon ◽  
Ye Tian
Keyword(s):  
Present Method ◽  
Vortex Lattice ◽  
Navier Stokes ◽  
Propeller Blade ◽  
Lattice Method ◽  
Viscous Potential Flow ◽  
Vortex Lattice Method ◽  
Hybrid Numerical Method ◽  
Effective Wake ◽  
Ducted Propellers

This paper presents the analysis of the performance for various ducted propellers using a hybrid numerical method, which couples a vortex lattice method (VLM) for the analysis of propellers and a Reynolds-Averaged Navier-Stokes solver for the prediction of the viscous fluid flow around the duct. The effects of viscosity on the effective wake and on the performance of the propeller blade, as well as on the predicted duct forces, are assessed. The prediction of the performance for those ducted propellers from the present method is validated against existing experimental data.

A Hybrid Viscous/Potential Flow Method for the Prediction of the Wetted and Cavitating Performance of Ducted Propellers

2012 ◽  
Author(s):  
Spyros A. Kinnas ◽  
Chan-Hoo Jeon ◽  
Ye Tian
Keyword(s):  
Present Method ◽  
Vortex Lattice ◽  
Navier Stokes ◽  
Propeller Blade ◽  
Lattice Method ◽  
Viscous Potential Flow ◽  
Vortex Lattice Method ◽  
Hybrid Numerical Method ◽  
Effective Wake ◽  
Ducted Propellers

This paper presents the analysis of the performance for various ducted propellers using a hybrid numerical method, which couples a vortex lattice method (VLM) for the analysis of propellers and a Reynolds-Averaged Navier-Stokes solver for the prediction of the viscous fluid flow around the duct. The effects of viscosity on the effective wake and on the performance of the propeller blade, as well as on the predicted duct forces, are assessed. The prediction of the performance for those ducted propellers from the present method is validated against existing experimental data.

A Hybrid Viscous/Potential Flow Method for the Prediction of the Performance of Podded and Ducted Propellers

2009 ◽  
Author(s):  
Spyros A. Kinnas ◽  
Shu-Hao Chang ◽  
Yi-Hsiang Yu ◽  
Lei He
Keyword(s):  
Viscous Flow ◽  
Lattice Method ◽  
Viscous Potential Flow ◽  
Flow Solver ◽  
Vortex Lattice Method ◽  
Ducted Propeller ◽  
Hybrid Numerical Method ◽  
Convergence Study ◽  
Effective Wake ◽  
Ducted Propellers

This paper presents the analysis of the performance for podded and ducted propellers using a hybrid numerical method, which couples a vortex lattice method (MPUF-3A) for the unsteady analysis of propellers and a viscous flow solver (NS-3X or FLUENT) for the prediction of the viscous flow around propulsors and the drag force on the pod and duct surfaces. The time averaged propeller force distributions are considered as source terms (body force) in the momentum equations of NS-3X and FLUENT. The effects of viscosity on the effective wake and on the performance of the propeller blade, as well as on the predicted pod and duct forces, are assessed. The convergence study of circulation distributions with number of lattices is reported in the ducted propeller case. Finally, the prediction of the performance for podded propellers (both single pull-type and twin-type) and ducted propellers from the present method is validated against existing experimental data.

Thruster and FPSO Hull Interaction

2014 ◽  
Author(s):  
Ye Tian ◽  
Spyros A. Kinnas
Keyword(s):  
Experimental Data ◽  
Hybrid Method ◽  
Computational Efficiency ◽  
Vortex Lattice ◽  
Numerical Results ◽  
Navier Stokes ◽  
Dynamic Positioning ◽  
Lattice Method ◽  
Vortex Lattice Method ◽  
Number Of Cells

A hybrid method which couples a Vortex-Lattice Method (VLM) solver and a Reynolds-Averaged Navier-Stokes (RANS) solver is applied to simulate the interaction between a Dynamic Positioning (DP) thruster and an FPSO hull. The hybrid method could significantly reduce the number of cells to fifth of that in a full blown RANS simulation and thus greatly enhance the computational efficiency. The numerical results are first validated with available experimental data, and then used to assess the significance of the thruster/hull interaction in DP systems.

Prediction of Unsteady Effective Wake by a Euler Solver/Vortex-Lattice Coupled Method

2003 ◽  
Vol 47 (02) ◽  
pp. 131-144
Author(s):  
Jin-Keun Choi ◽  
Spyros A. Kinnas
Keyword(s):  
Vortex Lattice ◽  
Three Dimensional ◽  
Lattice Method ◽  
Coupled Method ◽  
Vortex Lattice Method ◽  
Finite Volume Approach ◽  
Euler Solver ◽  
Effective Wake ◽  
Total Velocity ◽  
Surface Vortex

A fully three-dimensional Euler solver, based on a finite volume approach, is developed and applied to the prediction of the unsteady effective wake for propellers subject to non-axisymmetric inflows. The Euler solver is coupled with an existing lifting-surface vortex-lattice method for the computation of unsteady propeller flows. The coupled method is validated against the uniform inflow case, in which ideally the uniform flow should be recovered as the effective wake. The predicted total velocity field correlates very well with that measured in the water tunnel experiment. Lastly, the unsteady effective wake predicted by the present method is compared with the steady effective wake predicted by the authors' previous steady method.

A Prescribed-Wake Vortex Lattice Method for Preliminary Design of Co-Axial, Dual-Rotor Wind Turbines

2016 ◽  
Vol 138 (6) ◽  
Author(s):  
Aaron Rosenberg ◽  
Anupam Sharma
Keyword(s):  
Wind Turbines ◽  
Vortex Lattice ◽  
Navier Stokes ◽  
Wake Vortex ◽  
Preliminary Design ◽  
Lattice Method ◽  
Vortex Lattice Method ◽  
Trailing Vortices ◽  
Computational Fluid Dynamics Cfd ◽  
Reynolds Averaged Navier Stokes

This paper extends the prescribed-wake vortex lattice method (VLM) to perform aerodynamic analysis of dual-rotor wind turbines (DRWTs). A DRWT turbine consists of a large, primary rotor placed co-axially behind a smaller, secondary rotor. The additional vortex system introduced by the secondary rotor of a DRWT is modeled while taking into account the singularities that can occur when the trailing vortices from the secondary (upstream) rotor interact with the bound vortices of the main (downstream) rotor. Pseudo-steady assumption is invoked, and averaging over multiple relative rotor positions is performed to account for the primary and secondary rotors operating at different rotational velocities. The VLM solver is first validated against experiments and blade element momentum theory results for a conventional, single-rotor turbine. The solver is then verified for two DRWT designs against results from two computational fluid dynamics (CFD) methods: (1) Reynolds-averaged Navier–Stokes CFD with an actuator disk representation of the turbine rotors and (2) large-eddy simulations with an actuator line model. Radial distributions of sectional torque force and angle of attack show reasonable agreement between the three methods. Results of parametric sweeps performed using VLM agree qualitatively with the Reynolds-averaged Navier–Stokes (RANS) CFD results demonstrating that the proposed VLM can be used to guide preliminary design of DRWTs.

3D Simulation of a Convergent-Divergent Aero Engine Intake, Using Two Different CFD Methods

2005 ◽  
Author(s):  
Ioannis Templalexis ◽  
Pericles Pilidis ◽  
Geoffrey Guindeuil ◽  
Theodoros Lekas ◽  
Vassilios Pachidis
Keyword(s):  
Vortex Lattice ◽  
Cfd Simulation ◽  
Three Dimensional ◽  
Internal Flow ◽  
Navier Stokes ◽  
Lattice Method ◽  
Vortex Lattice Method ◽  
Aero Engine ◽  
Flow Effects ◽  
Development And Validation

This study refers to the development and validation of a Three Dimensional (3D) Vortex Lattice Method (VLM) to be used for internal flow case studies and more precisely aero-engine intake simulation. It examines the quantitative and qualitative response of the method to a convergent – divergent intake, produced as a surface of revolution of the CFM56-5B2 upper lip geometry. The study was carried out for three different sections namely: Intake outlet, intake throat and intake inlet. Moreover five different settings of Angle Of Attack (AOA) were considered. The VLM was based on an existing code. It was modified to accommodate internal flow effects and match, as closely as possible, the boundary conditions set by the Reynolds Average Navier-Stokes (RANS) Computational Fluid Dynamics (CFD) simulation. In the context of this study, Vortex Lattice-derived average values velocity profiles were compared against RANS CFD results.

Thruster and Hull Interaction

2015 ◽  
Vol 137 (4) ◽  
Author(s):  
Ye Tian ◽  
Spyros A. Kinnas
Keyword(s):  
Experimental Data ◽  
Hybrid Method ◽  
Computational Efficiency ◽  
Vortex Lattice ◽  
Numerical Results ◽  
Navier Stokes ◽  
Dynamic Positioning ◽  
Lattice Method ◽  
Vortex Lattice Method ◽  
Number Of Cells

A hybrid method which couples a vortex-lattice method (VLM) solver and a Reynolds-Averaged Navier–Stokes (RANS) solver is applied to simulate the interaction between a dynamic positioning (DP) thruster and a floating production storage and offloading (FPSO) hull. The hybrid method can significantly reduce the number of cells to fifth of that in a full-blown RANS simulation and thus greatly enhance the computational efficiency. The numerical results are first validated with available experimental data, and then used to assess the significance of the thruster/hull interaction in DP systems.

scholarly journals Aerodynamic Reduced-Order Modeling without Static Correction Requirement Based on Body Vortices

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Suwin Sleesongsom ◽  
Sujin Bureerat
Keyword(s):  
Present Method ◽  
Vortex Lattice ◽  
Three Dimensional ◽  
Unsteady Flows ◽  
Reduced Order Modeling ◽  
Reduced Order Models ◽  
Lattice Method ◽  
Reduced Order ◽  
Vortex Lattice Method ◽  
Static Correction

The objective of this research is to propose a new reduced-order modeling method. This approach is based on fluid eigenmodes and body vortices without using static correction. The vortex lattice method (VLM) is used to analyze unsteady flows over two-dimensional airfoil and three-dimensional wing. Eigenanalysis and reduced-order modeling are performed using a conventional method with static correction and an unconventional one without the static correction. Numerical examples are proposed to demonstrate the performance of the present method. The results show that the new method can be considered an alternative way to perform the reduced-order models of unsteady flow.

Prediction of Non-Axisymmetric Effective Wake by a Three-Dimensional Euler Solver

2001 ◽  
Vol 45 (01) ◽  
pp. 13-33
Author(s):  
Jin-Keun Choi ◽  
Spyros A. Kinnas
Keyword(s):  
Vortex Lattice ◽  
Three Dimensional ◽  
Lattice Method ◽  
Vortex Lattice Method ◽  
Actuator Disk ◽  
Finite Volume Approach ◽  
Euler Solver ◽  
Effective Wake ◽  
Total Velocity ◽  
Surface Vortex

A fully three-dimensional Euler solver, based on a finite volume approach, is developed and applied to the prediction of the effective wake for propellers subject to non-axisymmetric inflows. The method is coupled with an existing lifting-surface vortex-lattice method for the analysis of unsteady cavitating propeller flows. The results are validated against analytical solutions from actuator disk theory. The effect of the grid parameters on the results (circumferential average and amplitudes of harmonics of the predicted effective wake) is found to be very weak. The predicted total velocity field correlates very well with that measured in propeller experiments.

Generalized vortex lattice method for planar supersonic flow

AIAA Journal ◽  
1997 ◽  
Vol 35 ◽  
pp. 1230-1233
Author(s):  
Paulo A. O. Soviero ◽  
Hugo B. Resende
Keyword(s):  
Supersonic Flow ◽  
Vortex Lattice ◽  
Lattice Method ◽  
Vortex Lattice Method
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