International Journal of Engineering Systems Modelling and Simulation http://www.inderscience.com/browse/index.php?journalID=288&year=2012&vol=4&issue=1/2 Inderscience Publishers Ltd en-uk International Journal of Engineering Systems Modelling and Simulation 1755-9758 1755-9766 © 2012 Inderscience Publishers Ltd editor@inderscience.com https://www.inderscience.com/images/files/coverImgs/ijesms_scoverijesms.jpg http://www.inderscience.com/browse/index.php?journalID=288&year=2012&vol=4&issue=1/2 http://www.inderscience.com/link.php?id=44839 The present paper aims to summarise the activities from the Laboratory PRISME of the University of Orléans in the context of wind resource assessment with the '3%-vision' suggested by the European Wind Energy Technology Platform, and particularly of the wind turbine wake properties. Based on experimental investigations in an atmospheric boundary layer wind tunnel, some information about the diffusion process of the wind turbine far-wake, the minimal degree of modelling of the rotor to study its far-wake, the unsteady behaviour of the wake and the production loss due to wake effects are presented and discussed. Wind turbine wake: a disturbance to wind resource in wind farms
Sandrine Aubrun
International Journal of Engineering Systems Modelling and Simulation, Vol. 4, No. 1/2 (2012) pp. 2 - 10
The present paper aims to summarise the activities from the Laboratory PRISME of the University of Orléans in the context of wind resource assessment with the '3%-vision' suggested by the European Wind Energy Technology Platform, and particularly of the wind turbine wake properties. Based on experimental investigations in an atmospheric boundary layer wind tunnel, some information about the diffusion process of the wind turbine far-wake, the minimal degree of modelling of the rotor to study its far-wake, the unsteady behaviour of the wake and the production loss due to wake effects are presented and discussed.

]]> 10.1504/IJESMS.2012.044839 International Journal of Engineering Systems Modelling and Simulation, Vol. 4, No. 1/2 (2012) pp. 2 - 10 Sandrine Aubrun Laboratoire PRISME, Université d'Orléans, 8 rue Léonard de Vinci, F-45072 Oréans Cedex 2, France wind energy wind turbine wake wind turbines physical modelling porous disc actuator disc concept atmospheric turbulence length scales atmospheric boundary layer ABL wind resource assessment wind tunnels wind power rotors unsteady behaviour production loss. 2012-01-10T23:20:50-05:00 4 1/2 2 10 2012-01-10T23:20:50-05:00 http://www.inderscience.com/link.php?id=44840 The rotor of the model experiments under controlled conditions (MEXICO) wind turbine is modelled using the actuator surface (AS) method, wherein the blades are represented by singular surfaces of velocity and pressure discontinuities. A 3D control-volume finite-element method (CVFEM) is used to solve the Navier-Stokes equations, with appropriate adaptations to incorporate the AS action on the flow. The ability of the AS method to correctly model vorticity evolution and conservation in the wake of the MEXICO rotor is investigated. Experimental data in the form of PIV measurements collected from wind tunnel tests, as well as full CFD computations, are used for comparison purposes. This study is done in terms of the position, size, and strength of the vortices, which are determined using three analytical methods whose results are compared and discussed. Comparison with experimental results will help in determining how realistic the predictions from the AS model are, while comparison with full CFD computations will allow to shed light on the pros and cons of the AS method in comparison with full CFD computations. On the prediction of tip vortices in the near wake of the MEXICO rotor using the actuator surface method
Simon-Philippe Breton; Christophe Sibuet Watters; Christian Masson; Sugoi Gomez-Iradi; Xabier Munduate
International Journal of Engineering Systems Modelling and Simulation, Vol. 4, No. 1/2 (2012) pp. 11 - 26
The rotor of the model experiments under controlled conditions (MEXICO) wind turbine is modelled using the actuator surface (AS) method, wherein the blades are represented by singular surfaces of velocity and pressure discontinuities. A 3D control-volume finite-element method (CVFEM) is used to solve the Navier-Stokes equations, with appropriate adaptations to incorporate the AS action on the flow. The ability of the AS method to correctly model vorticity evolution and conservation in the wake of the MEXICO rotor is investigated. Experimental data in the form of PIV measurements collected from wind tunnel tests, as well as full CFD computations, are used for comparison purposes. This study is done in terms of the position, size, and strength of the vortices, which are determined using three analytical methods whose results are compared and discussed. Comparison with experimental results will help in determining how realistic the predictions from the AS model are, while comparison with full CFD computations will allow to shed light on the pros and cons of the AS method in comparison with full CFD computations.

]]> 10.1504/IJESMS.2012.044840 International Journal of Engineering Systems Modelling and Simulation, Vol. 4, No. 1/2 (2012) pp. 11 - 26 Simon-Philippe Breton; Christophe Sibuet Watters; Christian Masson; Sugoi Gomez-Iradi; Xabier Munduate Department of Mechanical Engineering, École de Technologie Supérieure, 1100 Notre-Dame Ouest, Montréal, Québec, H3C 1K3, Canada. ' Department of Mechanical Engineering, École de Technologie Supérieure, 1100 Notre-Dame Ouest, Montréal, Québec, H3C 1K3, Canada. ' Department of Mechanical Engineering, École de Technologie Supérieure, 1100 Notre-Dame Ouest, Montréal, Québec, H3C 1K3, Canada. ' CENER, Ciudad de la Innovación, no 7, 31621 Sarriguren (Navarra), Spain. ' CENER, Ciudad de la Innovación, no 7, 31621 Sarriguren (Navarra), Spain wind energy near wake vorticity actuator surfaces CFD computational fluid dynamics tip vortices wind turbines rotors wind energy wind power modelling control volume FEM finite element method CVFEM velocity pressure. 2012-01-10T23:20:50-05:00 4 1/2 11 26 2012-01-10T23:20:50-05:00 http://www.inderscience.com/link.php?id=44841 A detailed aerodynamic study of a 'humpy' high-speed propeller is presented. This propeller is the result of a bi-disciplinary optimisation procedure and features blade segments of wider chord bordered by narrow segments. The aerodynamic consequences of these regions are investigated and correlated to the aeroacoustic properties by comparison to an equivalent blade without hump. Aerodynamic study of a 'humpy' propeller
B.G. Marinus; W. Bosschaerts; M. Roger
International Journal of Engineering Systems Modelling and Simulation, Vol. 4, No. 1/2 (2012) pp. 27 - 35
A detailed aerodynamic study of a 'humpy' high-speed propeller is presented. This propeller is the result of a bi-disciplinary optimisation procedure and features blade segments of wider chord bordered by narrow segments. The aerodynamic consequences of these regions are investigated and correlated to the aeroacoustic properties by comparison to an equivalent blade without hump.

]]> 10.1504/IJESMS.2012.044841 International Journal of Engineering Systems Modelling and Simulation, Vol. 4, No. 1/2 (2012) pp. 27 - 35 B.G. Marinus; W. Bosschaerts; M. Roger Department of Mechanical Engineering, Royal Military Academy, B-1000 Brussels, Belgium. ' Department of Mechanical Engineering, Royal Military Academy, B-1000 Brussels, Belgium. ' Fluid Mechanics and Acoustics Laboratory, Ecole Centrale de Lyon, F-69134 Ecully, France high speed propellers aerodynamics aeroacoustics chord optimisation blade segments humps humpy blades propellor blades. 2012-01-10T23:20:50-05:00 4 1/2 27 35 2012-01-10T23:20:50-05:00 http://www.inderscience.com/link.php?id=44842 A comparison of the airloads on a propeller in incidence is done between experimental wind tunnel data, lifting-line results and unsteady Reynolds-averaged Navier-Stokes (URANS) calculations. The experimental behaviour of the high-speed, scale-model, APIAN propeller in the transonic S1MA wind tunnel at various angles of attack at Mach 0.20 and Mach 0.70 is successfully predicted by ONERA's computational fluid dynamics (CFD) code elsA. An assessment is done on the ability of the two numerical methods, namely lifting-line and URANS, to calculate propeller in-plane airloads. The importance of wake capture for accurate predictions is underlined and illustrated through comparisons on grid effects. Special emphasis is put on the airloads induced by the propeller on the spinner, which may amount up to 56% of the airloads on the propeller itself. Last, it is argued that neglecting these airloads biased the corrections done on the wind tunnel balance measurements. Assessment of propeller 1P loads predictions
Biel Ortun; Ronan Boisard; Ignacio Gonzalez-Martino
International Journal of Engineering Systems Modelling and Simulation, Vol. 4, No. 1/2 (2012) pp. 36 - 46
A comparison of the airloads on a propeller in incidence is done between experimental wind tunnel data, lifting-line results and unsteady Reynolds-averaged Navier-Stokes (URANS) calculations. The experimental behaviour of the high-speed, scale-model, APIAN propeller in the transonic S1MA wind tunnel at various angles of attack at Mach 0.20 and Mach 0.70 is successfully predicted by ONERA's computational fluid dynamics (CFD) code elsA. An assessment is done on the ability of the two numerical methods, namely lifting-line and URANS, to calculate propeller in-plane airloads. The importance of wake capture for accurate predictions is underlined and illustrated through comparisons on grid effects. Special emphasis is put on the airloads induced by the propeller on the spinner, which may amount up to 56% of the airloads on the propeller itself. Last, it is argued that neglecting these airloads biased the corrections done on the wind tunnel balance measurements.

]]> 10.1504/IJESMS.2012.044842 International Journal of Engineering Systems Modelling and Simulation, Vol. 4, No. 1/2 (2012) pp. 36 - 46 Biel Ortun; Ronan Boisard; Ignacio Gonzalez-Martino Onera – The French Aerospace Lab, Meudon, F-92190, France. ' Onera – The French Aerospace Lab, Meudon, F-92190, France. ' Airbus, Toulouse, 31060, France high speed propellers inflow angle incidence 1P URANS wind tunnels air loads in-plane balance corrections angle of attack wake capture load predictions computational fluid dynamics CFD. 2012-01-10T23:20:50-05:00 4 1/2 36 46 2012-01-10T23:20:50-05:00 http://www.inderscience.com/link.php?id=44843 Steady and unsteady Reynolds-averaged Navier-Stokes simulations have been achieved on a 3D centrifugal blower, typical of residential ventilation systems, installed in a volute including both tip clearance and flow leakages. The grid topology is found critical to predict global performances accurately and to preserve unsteady flow features necessary for future accurate acoustic predictions. A grid density larger than ten million cells is also required to correctly predict torque and static efficiency and to resolve flow recirculation and pressure losses in the blade passage. The turbulence model has a minor effect on the global performances of the machine. Both fluent and CFX yield similar overall performances even though local flow features differ and more asymmetry are obtained in the scroll with CFX. Finally, significant differences are observed between steady and unsteady simulations. Only URANS can provide a realistic fan interaction with the volute tongue. Numerical simulations of a low-speed radial fan
Marlene Sanjose; Stéphane Moreau
International Journal of Engineering Systems Modelling and Simulation, Vol. 4, No. 1/2 (2012) pp. 47 - 58
Steady and unsteady Reynolds-averaged Navier-Stokes simulations have been achieved on a 3D centrifugal blower, typical of residential ventilation systems, installed in a volute including both tip clearance and flow leakages. The grid topology is found critical to predict global performances accurately and to preserve unsteady flow features necessary for future accurate acoustic predictions. A grid density larger than ten million cells is also required to correctly predict torque and static efficiency and to resolve flow recirculation and pressure losses in the blade passage. The turbulence model has a minor effect on the global performances of the machine. Both fluent and CFX yield similar overall performances even though local flow features differ and more asymmetry are obtained in the scroll with CFX. Finally, significant differences are observed between steady and unsteady simulations. Only URANS can provide a realistic fan interaction with the volute tongue.

]]> 10.1504/IJESMS.2012.044843 International Journal of Engineering Systems Modelling and Simulation, Vol. 4, No. 1/2 (2012) pp. 47 - 58 Marlene Sanjose; Stéphane Moreau GAUS, Mechanical Engineering, Université de Sherbrooke, 2500 boulevard de l'Université, Sherbrooke QC J1K 2R1, Canada. ' GAUS, Mechanical Engineering, Université de Sherbrooke, 2500 boulevard de l'Université, Sherbrooke QC J1K 2R1, Canada centrifugal fans computational fluid dynamics CFD turbomachinery unsteady flow low speed fans radial fans simulation centrifugal blowers residential ventilation systems clearance flow leakages turbulence modelling URANS fan interaction volute tongue torque static efficiency flow recirculation pressure losses. 2012-01-10T23:20:50-05:00 4 1/2 47 58 2012-01-10T23:20:50-05:00 http://www.inderscience.com/link.php?id=44844 The renewed interest in the contra-rotating open rotor (CROR) as a potential highly efficient powerplant for future transport aircraft has prompted a study into the aerodynamic and aeroacoustic performance of this type of engine at DLR. With significant technical challenges related to the noise emissions and installation effects remaining to be addressed prior to realisation of a viable engine of this type, a study of a generic pusher-configuration CROR propulsion system is presented, which focuses on the impact of installation effects on the rotor aerodynamics and noise emissions. The two primary installation effects angle of attack and the pylon wake are studied utilising a high-fidelity coupled analysis based on unsteady Reynolds averaged Navier-Stokes (uRANS) simulations with the CFD solver TAU and the aeroacoustic analysis tool APSIM, both developed at DLR, highlighting the importance of these aspects on CROR in-plane loads and rotor noise emissions. Installation impact on pusher CROR engine low speed performance and noise emission characteristics
A. Stuermer; Jianping Yin
International Journal of Engineering Systems Modelling and Simulation, Vol. 4, No. 1/2 (2012) pp. 59 - 68
The renewed interest in the contra-rotating open rotor (CROR) as a potential highly efficient powerplant for future transport aircraft has prompted a study into the aerodynamic and aeroacoustic performance of this type of engine at DLR. With significant technical challenges related to the noise emissions and installation effects remaining to be addressed prior to realisation of a viable engine of this type, a study of a generic pusher-configuration CROR propulsion system is presented, which focuses on the impact of installation effects on the rotor aerodynamics and noise emissions. The two primary installation effects angle of attack and the pylon wake are studied utilising a high-fidelity coupled analysis based on unsteady Reynolds averaged Navier-Stokes (uRANS) simulations with the CFD solver TAU and the aeroacoustic analysis tool APSIM, both developed at DLR, highlighting the importance of these aspects on CROR in-plane loads and rotor noise emissions.

]]> 10.1504/IJESMS.2012.044844 International Journal of Engineering Systems Modelling and Simulation, Vol. 4, No. 1/2 (2012) pp. 59 - 68 A. Stuermer; Jianping Yin DLR Institute of Aerodynamics and Flow Technology, Lilienthalplatz 7, 38108 Braunschweig, Germany. ' DLR Institute of Aerodynamics and Flow Technology, Lilienthalplatz 7, 38108 Braunschweig, Germany contra-rotating open rotors CROR engines installation effects uRANS CAA rotor noise unsteady aerodynamics interaction tones multi-disciplinary simulation 1P loads low speed performance noise emissions transport aircraft aeroacoustics CROR propulsion systems simulation angle of attack pylon wake. 2012-01-10T23:20:50-05:00 4 1/2 59 68 2012-01-10T23:20:50-05:00 http://www.inderscience.com/link.php?id=44845 The transition prediction capability of two semi-/empirical criteria originating from fixed wing applications is studied for steady, rotary wing application. This includes the AHD criterion, and two variants of the Michel criterion. Both criteria are used with approximated boundary layer data for improved numerical robustness of the prediction algorithm in an industrial context. The transition criteria have been implemented in the structured flow solver FLOWer of the German Aerospace Center (DLR). A two-dimensional airfoil test case (Somers NLF(1)-0416) is used to study the prediction accuracy of the criteria, comparing three different one and two equation turbulence models. A three-dimensional rotor test case at hover (DLR Bo 105 flight test) serves to validate the computed transition locations. A relative comparison of the predicted rotor efficiency illustrates the differences in performance prediction between the AHD and the Michel criterion. Semi-/empirical transition prediction and application to an isolated rotor in hover
C.C. Heister
International Journal of Engineering Systems Modelling and Simulation, Vol. 4, No. 1/2 (2012) pp. 69 - 78
The transition prediction capability of two semi-/empirical criteria originating from fixed wing applications is studied for steady, rotary wing application. This includes the AHD criterion, and two variants of the Michel criterion. Both criteria are used with approximated boundary layer data for improved numerical robustness of the prediction algorithm in an industrial context. The transition criteria have been implemented in the structured flow solver FLOWer of the German Aerospace Center (DLR). A two-dimensional airfoil test case (Somers NLF(1)-0416) is used to study the prediction accuracy of the criteria, comparing three different one and two equation turbulence models. A three-dimensional rotor test case at hover (DLR Bo 105 flight test) serves to validate the computed transition locations. A relative comparison of the predicted rotor efficiency illustrates the differences in performance prediction between the AHD and the Michel criterion.

]]> 10.1504/IJESMS.2012.044845 International Journal of Engineering Systems Modelling and Simulation, Vol. 4, No. 1/2 (2012) pp. 69 - 78 C.C. Heister German Aerospace Center (DLR), Institute of Aerodynamics and Flow Technology, Helicopters, Lilienthalplatz 7, D-38108 Braunschweig, Germany transition prediction empirical AHD Michel criterion boundary layers approximation CFD computational fluid dynamics FLOWer helicopters isolated rotors hover performance flight test rotary wings turbulence modelling rotor efficiency. 2012-01-10T23:20:50-05:00 4 1/2 69 78 2012-01-10T23:20:50-05:00 http://www.inderscience.com/link.php?id=44846 This work presents a method for the optimisation of aspects of rotor blade shape in forward flight. The proposed technique employs CFD in conjunction with artificial neural networks (ANNs) and genetic algorithms (GAs). The developed method was used to optimise the anhedral and sweep of the UH60-A rotor blade in forward flight. A parameterisation method was defined, a specific objective function was created using the initial CFD data and the metamodel was used for evaluating the objective function during the optimisation. The obtained results suggest optima in agreement with engineering intuition but provide precise information about the shape of the final lifting surface and its performance. The results were checked using different optimisation methods and metamodels and were not sensitive to the employed techniques with substantial overlap between the outputs of the selected methods. The main CPU cost was associated with populating the CFD database necessary for the metamodel. Optimisation of aspects of rotor blades in forward flight
Catherine S. Johnson; Mark Woodgate; George N. Barakos
International Journal of Engineering Systems Modelling and Simulation, Vol. 4, No. 1/2 (2012) pp. 79 - 93
This work presents a method for the optimisation of aspects of rotor blade shape in forward flight. The proposed technique employs CFD in conjunction with artificial neural networks (ANNs) and genetic algorithms (GAs). The developed method was used to optimise the anhedral and sweep of the UH60-A rotor blade in forward flight. A parameterisation method was defined, a specific objective function was created using the initial CFD data and the metamodel was used for evaluating the objective function during the optimisation. The obtained results suggest optima in agreement with engineering intuition but provide precise information about the shape of the final lifting surface and its performance. The results were checked using different optimisation methods and metamodels and were not sensitive to the employed techniques with substantial overlap between the outputs of the selected methods. The main CPU cost was associated with populating the CFD database necessary for the metamodel.

]]> 10.1504/IJESMS.2012.044846 International Journal of Engineering Systems Modelling and Simulation, Vol. 4, No. 1/2 (2012) pp. 79 - 93 Catherine S. Johnson; Mark Woodgate; George N. Barakos CFD Laboratory, School of Engineering, University of Liverpool, L69 3GH, UK. ' CFD Laboratory, School of Engineering, University of Liverpool, L69 3GH, UK. ' CFD Laboratory, School of Engineering, University of Liverpool, L69 3GH, UK; Kazan State Technical University, named after A.N. Tupolev, 10 K. Marx St., Kazan 420111, Russian Federation, Russia aerodynamics helicopter rotor design optimisation genetic algorithms GAs artificial neural networks ANNs metamodelling computational fluid dynamics CFD UH60-A harmonic balance rotors rotor blade shape forward flight helicopters. 2012-01-10T23:20:50-05:00 4 1/2 79 93 2012-01-10T23:20:50-05:00 http://www.inderscience.com/link.php?id=44847 We herein present a direct numerical simulation method aimed at describing the dynamics of helical vortices such as those developing in the wake of propellers and wind turbine or helicopter rotors. By enforcing a helical symmetry, the 3D incompressible Navier-Stokes equations are reduced to a 2D problem which we solve using a generalised vorticity/streamfunction formulation. In this framework, we simulate the viscous dynamics of one or several helical vortices and describe quasi-steady states as well as long-time (or far-wake) dynamics. In particular, several types of merging in the two helical vortex systems are identified. Direct numerical simulation of helical vortices
Ivan Delbende; Maurice Rossi; Benjamin Piton
International Journal of Engineering Systems Modelling and Simulation, Vol. 4, No. 1/2 (2012) pp. 94 - 101
We herein present a direct numerical simulation method aimed at describing the dynamics of helical vortices such as those developing in the wake of propellers and wind turbine or helicopter rotors. By enforcing a helical symmetry, the 3D incompressible Navier-Stokes equations are reduced to a 2D problem which we solve using a generalised vorticity/streamfunction formulation. In this framework, we simulate the viscous dynamics of one or several helical vortices and describe quasi-steady states as well as long-time (or far-wake) dynamics. In particular, several types of merging in the two helical vortex systems are identified.

]]> 10.1504/IJESMS.2012.044847 International Journal of Engineering Systems Modelling and Simulation, Vol. 4, No. 1/2 (2012) pp. 94 - 101 Ivan Delbende; Maurice Rossi; Benjamin Piton UPMC, Université Pierre et Marie Curie-Paris 6, LIMSI-CNRS, UPR3251, BP133, 91403 Orsay Cedex, France. ' UPMC, Université Pierre et Marie Curie-Paris 6, IJLRA-UPMC, UMR7190, 75232 Paris Cedex 05, France. ' UPMC, Université Pierre et Marie Curie-Paris 6, LIMSI-CNRS, UPR3251, BP133, 91403 Orsay Cedex, France vortex dynamics vortex merging helical vortices Navier-Stokes equations numerical simulation wake propellers wind turbines helicopter rotors viscous dynamics. 2012-01-10T23:20:50-05:00 4 1/2 94 101 2012-01-10T23:20:50-05:00 http://www.inderscience.com/link.php?id=44848 The VC2 vorticity confinement technique introduced by Steinhoff for vortex dominated flows is presented. After a brief description of the formulation and of its theoretical developments, the method is applied to the simulation of helicopter rotor wakes, focusing on two configurations: the rotor in hover, for which the flow field is mainly driven by the wake characteristics, and the rotor in low-speed descent flight where BVI noise is created. The results obtained show the efficiency of the approach, which provides wake predictions of the same or even better quality as higher-order methods. Application of vorticity confinement to rotor wake simulations
Michel Costes; Thomas Renaud; Benoit Rodriguez; Gabriel Reboul
International Journal of Engineering Systems Modelling and Simulation, Vol. 4, No. 1/2 (2012) pp. 102 - 112
The VC2 vorticity confinement technique introduced by Steinhoff for vortex dominated flows is presented. After a brief description of the formulation and of its theoretical developments, the method is applied to the simulation of helicopter rotor wakes, focusing on two configurations: the rotor in hover, for which the flow field is mainly driven by the wake characteristics, and the rotor in low-speed descent flight where BVI noise is created. The results obtained show the efficiency of the approach, which provides wake predictions of the same or even better quality as higher-order methods.

]]> 10.1504/IJESMS.2012.044848 International Journal of Engineering Systems Modelling and Simulation, Vol. 4, No. 1/2 (2012) pp. 102 - 112 Michel Costes; Thomas Renaud; Benoit Rodriguez; Gabriel Reboul ONERA, The French Aerospace Lab, 8 rue des Vertugadins, F 92190 Meudon, France. ' ONERA, The French Aerospace Lab, 8 rue des Vertugadins, F 92190 Meudon, France. ' ONERA, The French Aerospace Lab, 8 rue des Vertugadins, F 92190 Meudon, France. ' ONERA, The French Aerospace Lab, F 92320 Châtillon, France helicopter rotor wakes vorticity confinement hovering flight descent flight blade-vortex interaction rotors helicopters vortex flows simulation wake predictions. 2012-01-10T23:20:50-05:00 4 1/2 102 112 2012-01-10T23:20:50-05:00