The Experts below are selected from a list of 8433 Experts worldwide ranked by ideXlab platform

Reinhard Moenig - One of the best experts on this subject based on the ideXlab platform.

  • advanced nonaxisymmetric endwall contouring for axial Compressors by generating an aerodynamic separator part i principal cascade design and Compressor Application
    Journal of Turbomachinery-transactions of The Asme, 2011
    Co-Authors: Christian Dorfner, Alexander Hergt, Eberhard Nicke, Reinhard Moenig
    Abstract:

    Modern methods for axial Compressor design are capable of shaping the blade surfaces in a three-dimensional way. Linking these methods with automated optimization techniques provides a major benefit to the design process. The Application of nonaxisymmetric contoured endwalls is considered to be very successful in turbine rotors and vanes. Concerning axial Compressors, nonaxisymmetric endwalls are still a field of research. This two-part paper presents the recent development of a novel endwall design. An aerodynamic separator, generated by a nonaxisymmetric endwall groove, interacts with the passage vortex. This major impact on the secondary flow results in a significant loss reduction because of load redistribution, reduction in recirculation areas, and suppressed corner separation. The first paper deals with the development of the initial endwall design using a linear Compressor cascade Application. A brief introduction of the design methods is provided, including the automated optimization and the 3D process chain with a focus on the endwall contouring tool. Hereafter, the resulting flow phenomena and physics due to the modified endwall surface are described and analyzed in detail. Additionally, the endwall design principal is transferred to an axial Compressor stage. The endwall groove is applied to the hub and casing endwalls of the stator, and the initial numerical investigation is presented. For highly loaded operating points, the flow behavior at the hub region can be improved in accord with the cascade results. Obviously, the casing region is dominated by the incoming tip vortex generated by the rotor and still remains an area for further investigations concerning nonaxisymmetric endwall contouring.

  • advanced non axisymmetric endwall contouring for axial Compressors by generating an aerodynamic separator part i principal cascade design and Compressor Application
    ASME Turbo Expo 2009: Power for Land Sea and Air, 2009
    Co-Authors: Christian Dorfner, Alexander Hergt, Eberhard Nicke, Reinhard Moenig
    Abstract:

    Modern methods for axial Compressor design are capable of shaping the blade surfaces in a three dimensional way. Linking these methods with automated optimization techniques provides a major benefit to the design process. The Application of non-axisymmetric contoured endwalls is considered to be very successful in turbine rotors and vanes. Concerning axial Compressors non-axisymmetric endwalls are still a field of research. This two-part paper presents the recent development of a novel endwall design. An aerodynamic separator, generated by a non-axisymmetric endwall groove, interacts with the passage vortex. This major impact on the secondary flow results in a significant loss reduction because of load redistribution, reduction of recirculation areas and suppressed corner separation. The first paper deals with the development of the initial endwall design using a linear Compressor cascade Application. A brief introduction of the design methods is provided, including the automated optimization, the 3D process chain with a focus on the endwall contouring tool. Hereafter the resulting flow phenomena and physics due to the modified endwall surface are described and analyzed in detail. Additionally, the endwall design principal is transferred to an axial Compressor stage. The endwall groove is applied to the hub and casing endwalls of the stator and the initial numerical investigation is presented. For highly loaded operating points the flow behaviour at the hub region can be improved in accord with the cascade results. Obviously, the casing region is dominated by the incoming tip vortex generated by the rotor and still remains an area for further investigations concerning non-axisymmetric endwall contouring.Copyright © 2009 by ASME

Christian Dorfner - One of the best experts on this subject based on the ideXlab platform.

  • advanced nonaxisymmetric endwall contouring for axial Compressors by generating an aerodynamic separator part ii experimental and numerical cascade investigation
    Journal of Turbomachinery-transactions of The Asme, 2011
    Co-Authors: Alexander Hergt, Christian Dorfner, Wolfgang Steinert, Eberhard Nicke, Heinzadolf Schreiber
    Abstract:

    Modern methods for axial Compressor design are capable of shaping the blade surfaces in a three-dimensional way. Linking these methods with automated optimization techniques provides a major benefit to the design process. The Application of nonaxisymmetric contoured endwalls is considered to be very successful in turbine rotors and vanes. Concerning axial Compressors, nonaxisymmetric endwalls are still a field of research. This two-part paper presents the recent development of a novel endwall design. A vortex created by a nonaxisymmetric endwall groove acts as an aerodynamic separator, preventing the passage vortex from interacting with the suction side boundary layer. This major impact on the secondary flow results in a significant loss reduction by means of load redistribution, reduction in recirculation areas, and suppressed corner separation. Part I of this paper deals with the endwall design and its Compressor Application. The resulting flow phenomena and physics are described and analyzed in detail. The second paper presents the detailed experimental and numerical investigation of the developed endwall groove. The measurements carried out at the transonic cascade wind tunnel of DLR in Cologne, demonstrated a considerable influence on the cascade performance. A loss reduction and redistribution of the cascade loading were achieved at the aerodynamic design point, as well as near the stall condition of the cascade. This behavior is well predicted by the numerical simulation. The combined analysis of experimental and numerical flow patterns allows a detailed interpretation and description of the resulting flow phenomena. In this context, high fidelity 3D-Reynolds-averaged Navier―Stokes flow simulations are required to analyze the complex blade and endwall boundary layer interaction.

  • advanced nonaxisymmetric endwall contouring for axial Compressors by generating an aerodynamic separator part i principal cascade design and Compressor Application
    Journal of Turbomachinery-transactions of The Asme, 2011
    Co-Authors: Christian Dorfner, Alexander Hergt, Eberhard Nicke, Reinhard Moenig
    Abstract:

    Modern methods for axial Compressor design are capable of shaping the blade surfaces in a three-dimensional way. Linking these methods with automated optimization techniques provides a major benefit to the design process. The Application of nonaxisymmetric contoured endwalls is considered to be very successful in turbine rotors and vanes. Concerning axial Compressors, nonaxisymmetric endwalls are still a field of research. This two-part paper presents the recent development of a novel endwall design. An aerodynamic separator, generated by a nonaxisymmetric endwall groove, interacts with the passage vortex. This major impact on the secondary flow results in a significant loss reduction because of load redistribution, reduction in recirculation areas, and suppressed corner separation. The first paper deals with the development of the initial endwall design using a linear Compressor cascade Application. A brief introduction of the design methods is provided, including the automated optimization and the 3D process chain with a focus on the endwall contouring tool. Hereafter, the resulting flow phenomena and physics due to the modified endwall surface are described and analyzed in detail. Additionally, the endwall design principal is transferred to an axial Compressor stage. The endwall groove is applied to the hub and casing endwalls of the stator, and the initial numerical investigation is presented. For highly loaded operating points, the flow behavior at the hub region can be improved in accord with the cascade results. Obviously, the casing region is dominated by the incoming tip vortex generated by the rotor and still remains an area for further investigations concerning nonaxisymmetric endwall contouring.

  • advanced non axisymmetric endwall contouring for axial Compressors by generating an aerodynamic separator part i principal cascade design and Compressor Application
    ASME Turbo Expo 2009: Power for Land Sea and Air, 2009
    Co-Authors: Christian Dorfner, Alexander Hergt, Eberhard Nicke, Reinhard Moenig
    Abstract:

    Modern methods for axial Compressor design are capable of shaping the blade surfaces in a three dimensional way. Linking these methods with automated optimization techniques provides a major benefit to the design process. The Application of non-axisymmetric contoured endwalls is considered to be very successful in turbine rotors and vanes. Concerning axial Compressors non-axisymmetric endwalls are still a field of research. This two-part paper presents the recent development of a novel endwall design. An aerodynamic separator, generated by a non-axisymmetric endwall groove, interacts with the passage vortex. This major impact on the secondary flow results in a significant loss reduction because of load redistribution, reduction of recirculation areas and suppressed corner separation. The first paper deals with the development of the initial endwall design using a linear Compressor cascade Application. A brief introduction of the design methods is provided, including the automated optimization, the 3D process chain with a focus on the endwall contouring tool. Hereafter the resulting flow phenomena and physics due to the modified endwall surface are described and analyzed in detail. Additionally, the endwall design principal is transferred to an axial Compressor stage. The endwall groove is applied to the hub and casing endwalls of the stator and the initial numerical investigation is presented. For highly loaded operating points the flow behaviour at the hub region can be improved in accord with the cascade results. Obviously, the casing region is dominated by the incoming tip vortex generated by the rotor and still remains an area for further investigations concerning non-axisymmetric endwall contouring.Copyright © 2009 by ASME

Ahmed Kovacevic - One of the best experts on this subject based on the ideXlab platform.

  • Optimisation of screw Compressors
    Applied Thermal Engineering, 2003
    Co-Authors: Nikola Stosic, Ian K. Smith, Ahmed Kovacevic
    Abstract:

    Increasing demands for more efficient screw Compressors require that Compressor designs are tailored upon their duty, capacity and manufacturing capability. A suitable procedure for optimisation of the screw Compressor shape, size, dimension and operating parameters is described here, which results in the most appropriate design for a given Compressor Application and fluid. It is based on a rack generation algorithm for rotor profile combined with a numerical model of the Compressor fluid flow and thermodynamic processes. Some optimisation issues of the rotor profile and Compressor parts are discussed, using 5/6 screw Compressor rotors to present the results. It is shown that the optimum rotor profile, Compressor speed, oil flow rate and temperature may significantly differ when compressing different gases or vapours or if working at the oil-free or oil-flooded mode of operation. Compressors thus designed achieve higher delivery rates and better efficiencies than those using traditional approaches, which is illustrated in an example of the 3/5 screw rotors designed for a family of dry air Compressors, produced and marketed by a renown British Compressor manufacturer.

Alexander Hergt - One of the best experts on this subject based on the ideXlab platform.

  • advanced nonaxisymmetric endwall contouring for axial Compressors by generating an aerodynamic separator part ii experimental and numerical cascade investigation
    Journal of Turbomachinery-transactions of The Asme, 2011
    Co-Authors: Alexander Hergt, Christian Dorfner, Wolfgang Steinert, Eberhard Nicke, Heinzadolf Schreiber
    Abstract:

    Modern methods for axial Compressor design are capable of shaping the blade surfaces in a three-dimensional way. Linking these methods with automated optimization techniques provides a major benefit to the design process. The Application of nonaxisymmetric contoured endwalls is considered to be very successful in turbine rotors and vanes. Concerning axial Compressors, nonaxisymmetric endwalls are still a field of research. This two-part paper presents the recent development of a novel endwall design. A vortex created by a nonaxisymmetric endwall groove acts as an aerodynamic separator, preventing the passage vortex from interacting with the suction side boundary layer. This major impact on the secondary flow results in a significant loss reduction by means of load redistribution, reduction in recirculation areas, and suppressed corner separation. Part I of this paper deals with the endwall design and its Compressor Application. The resulting flow phenomena and physics are described and analyzed in detail. The second paper presents the detailed experimental and numerical investigation of the developed endwall groove. The measurements carried out at the transonic cascade wind tunnel of DLR in Cologne, demonstrated a considerable influence on the cascade performance. A loss reduction and redistribution of the cascade loading were achieved at the aerodynamic design point, as well as near the stall condition of the cascade. This behavior is well predicted by the numerical simulation. The combined analysis of experimental and numerical flow patterns allows a detailed interpretation and description of the resulting flow phenomena. In this context, high fidelity 3D-Reynolds-averaged Navier―Stokes flow simulations are required to analyze the complex blade and endwall boundary layer interaction.

  • advanced nonaxisymmetric endwall contouring for axial Compressors by generating an aerodynamic separator part i principal cascade design and Compressor Application
    Journal of Turbomachinery-transactions of The Asme, 2011
    Co-Authors: Christian Dorfner, Alexander Hergt, Eberhard Nicke, Reinhard Moenig
    Abstract:

    Modern methods for axial Compressor design are capable of shaping the blade surfaces in a three-dimensional way. Linking these methods with automated optimization techniques provides a major benefit to the design process. The Application of nonaxisymmetric contoured endwalls is considered to be very successful in turbine rotors and vanes. Concerning axial Compressors, nonaxisymmetric endwalls are still a field of research. This two-part paper presents the recent development of a novel endwall design. An aerodynamic separator, generated by a nonaxisymmetric endwall groove, interacts with the passage vortex. This major impact on the secondary flow results in a significant loss reduction because of load redistribution, reduction in recirculation areas, and suppressed corner separation. The first paper deals with the development of the initial endwall design using a linear Compressor cascade Application. A brief introduction of the design methods is provided, including the automated optimization and the 3D process chain with a focus on the endwall contouring tool. Hereafter, the resulting flow phenomena and physics due to the modified endwall surface are described and analyzed in detail. Additionally, the endwall design principal is transferred to an axial Compressor stage. The endwall groove is applied to the hub and casing endwalls of the stator, and the initial numerical investigation is presented. For highly loaded operating points, the flow behavior at the hub region can be improved in accord with the cascade results. Obviously, the casing region is dominated by the incoming tip vortex generated by the rotor and still remains an area for further investigations concerning nonaxisymmetric endwall contouring.

  • advanced non axisymmetric endwall contouring for axial Compressors by generating an aerodynamic separator part i principal cascade design and Compressor Application
    ASME Turbo Expo 2009: Power for Land Sea and Air, 2009
    Co-Authors: Christian Dorfner, Alexander Hergt, Eberhard Nicke, Reinhard Moenig
    Abstract:

    Modern methods for axial Compressor design are capable of shaping the blade surfaces in a three dimensional way. Linking these methods with automated optimization techniques provides a major benefit to the design process. The Application of non-axisymmetric contoured endwalls is considered to be very successful in turbine rotors and vanes. Concerning axial Compressors non-axisymmetric endwalls are still a field of research. This two-part paper presents the recent development of a novel endwall design. An aerodynamic separator, generated by a non-axisymmetric endwall groove, interacts with the passage vortex. This major impact on the secondary flow results in a significant loss reduction because of load redistribution, reduction of recirculation areas and suppressed corner separation. The first paper deals with the development of the initial endwall design using a linear Compressor cascade Application. A brief introduction of the design methods is provided, including the automated optimization, the 3D process chain with a focus on the endwall contouring tool. Hereafter the resulting flow phenomena and physics due to the modified endwall surface are described and analyzed in detail. Additionally, the endwall design principal is transferred to an axial Compressor stage. The endwall groove is applied to the hub and casing endwalls of the stator and the initial numerical investigation is presented. For highly loaded operating points the flow behaviour at the hub region can be improved in accord with the cascade results. Obviously, the casing region is dominated by the incoming tip vortex generated by the rotor and still remains an area for further investigations concerning non-axisymmetric endwall contouring.Copyright © 2009 by ASME

Daniel Sadarnac - One of the best experts on this subject based on the ideXlab platform.

  • multiphysic modeling of a high speed interior permanent magnet synchronous machine for a multiobjective optimal design
    IEEE Transactions on Energy Conversion, 2011
    Co-Authors: Xavier Jannot, Jeanclaude Vannier, Claude Marchand, M Gabsi, Jacques Saintmichel, Daniel Sadarnac
    Abstract:

    High-speed electric drive design is concerned with paying particular attention to thermal and mechanical design of the machine. Therefore, this paper proposes a multiphysic modeling of an interior permanent-magnet synchronous machine (IPMSM) dedicated to high speed, including magnetic, electric, thermal, and mechanical aspects. The proposed analytical models are verified using finite-element (FE) computations. These models are then subjected to a multiobjective optimization-based on genetic algorithm-to design an IPMSM for a high-speed Compressor Application that develops 30 kW at 20 000 r/min. The design is formulated as a constrained optimization problem consisting of maximizing the machine efficiency while minimizing its weight. The result of this process is a Pareto front between efficiency and weight of the machine allowing the designer to make a posteriori choice. A particular optimal machine is chosen and its performances are validated with FE analysis. This study carries out an optimal multiphysic and multiobjective design approach that allows rationalization of the design process in a realistic computation time thanks to the analytical models involved.