Andrea Arnone | Università degli Studi di Firenze (University of Florence) (original) (raw)
Papers by Andrea Arnone
Volume 5: Turbo Expo 2004, Parts A and B, 2004
Numerical optimization techniques are increasingly used in the aerodynamic design of turbomachine... more Numerical optimization techniques are increasingly used in the aerodynamic design of turbomachine blades.
Volume 6: Turbomachinery, Parts A and B, 2006
A time-linearized quasi-3D solver for flutter analysis in turbomachinery flows was modified in or... more A time-linearized quasi-3D solver for flutter analysis in turbomachinery flows was modified in order to deal with incoming perturbations due to unsteady interactions with upstream/downstream rows. To do this, exact two-dimensional single-frequency non-reflecting boundary ...
Efficient acceleration techniques typical of explicit steady-state solvers are extended to time-a... more Efficient acceleration techniques typical of explicit steady-state solvers are extended to time-accurate calculations. Stability restrictions are greatly reduced by means of a fully implicit time discretization. A four-stage Runge-Kutta scheme with local time stepping, residual smoothing, and multigridding is used instead of traditional time-expensive factorizations. Some applications to natural and forced unsteady viscous flows show the capability of the procedure.
Rotor-stator interaction analysis using the Navier-Stokes equations and a multigrid method. Andre... more Rotor-stator interaction analysis using the Navier-Stokes equations and a multigrid method. Andrea Arnone, Roberto Pacciani AM SOC MECH ENG PAP, 15, 1995. A recently developed, time-accurate multigrid viscous solver ...
Transition modeling effects on turbine rotor blade heat transfer predictions. Ali A Ameri, Andrea... more Transition modeling effects on turbine rotor blade heat transfer predictions. Ali A Ameri, Andrea Arnone ASME, International Gas Turbine and Aeroengine Congress and Exposition, The Hague, Netherlands, 1994. The effect ...
Navier-Stokes calculations were carried out in order to predict the heat transfer rates on turbin... more Navier-Stokes calculations were carried out in order to predict the heat transfer rates on turbine blades. The calculations were performed using TRAF2D which is a two-dimensional, explicit, finite volume mass-averaged Navier-Stokes solver. Turbulence was modeled using q-omega and k-epsilon two-equation models and the Baldwin-Lomax algebraic model. The model equations along with the flow equations were solved explicitly on a non-periodic C grid. Implicit residual smoothing (IRS) or a combination of multigrid technique and IRS was applied to enhance convergence rates. Calculations were performed to predict the Stanton number distributions on the first stage vane and blade row as well as the second stage vane row of the Rocketdyne Space Shuttle Main Engine (SSME) high pressure fuel turbine. The comparison with the experimental results, although generally favorable, serves to highlight the weaknesses of the turbulence models and the possible areas of improving these models for use in tu...
The performance of a Low-Pressure Turbine (LPT) cascade were investigated under both steady and p... more The performance of a Low-Pressure Turbine (LPT) cascade were investigated under both steady and periodic unsteady inflow boundary conditions with different Reynolds numbers and a reduced frequency representative of real LPT working conditions. A sensitivity analysis to the variation of the inlet flow angle was performed to assess the performance during off-design operation. The numerical framework is based on a steady/unsteady Reynolds Averaged Navier-Stokes (RANS/URANS) flow solver which includes some state-of-the-art transition-sensitive turbulence closures. Boundary conditions for the time-accurate computations upstream of the cascade were derived from the experimental characterization of a moving bar system used to generate the wake periodic perturbations. The computed performance of the cascade, as a function of Reynolds number and incidence angle variation, is discussed in comparison with experimental data. Steady and unsteady boundary layer quantities are also compared with m...
This paper presents an efficient “Phase-Lagged” method developed for turbomachinery applications.... more This paper presents an efficient “Phase-Lagged” method developed for turbomachinery applications. The method is based on the Generalized-Shape-Correction model. Moving averages techniques as well as double-passage domain formulation were adopted in order to reduce memory requirements and improve the model robustness. The model was used to evaluate the aerodynamic performance of the high pressure transonic turbine stage CT3, experimentally studied at the von Karman Institute for Fluid Dynamics within the EU funded TATEF2 project. Results are discussed and compared with both the available experimental data and the results obtained by means of both steady and unsteady scaled Full-Annulus approaches. Computational requirements of the GSC model are evaluated and presented showing that nowadays unsteady results can be reached at an affordable computational cost.
The present activity was carried out in the framework of the Clean Sky European research project ... more The present activity was carried out in the framework of the Clean Sky European research project ITURB (”Optimal High-Lift Turbine Blade Aero-Mechanical Design”), aimed at designing and validating a turbine blade for a geared open rotor engine. A cold-flow, large-scale, low-speed (LS) rig was built in order to investigate and validate new design criteria, providing reliable and detailed results while containing costs. This paper presents the design of a LS stage, and describes a general procedure that allows to scale 3D blades for low-speed testing. The design of the stator row was aimed at matching the test-rig inlet conditions and at providing the proper inlet flow field to the blade row. The rotor row was redesigned in order to match the performance of the high-speed one, compensating for both the compressibility effects and different turbine flow paths. The proposed scaling procedure is based on the matching of the 3D blade loading distribution between the real engine environmen...
Volume 4: Heat Transfer; Electric Power; Industrial and Cogeneration, 1994
Prediction of turbine blade passage heat transfer using a zero and a two-equation turbulence mode... more Prediction of turbine blade passage heat transfer using a zero and a two-equation turbulence model. Ali A Ameri, Andrea Arnone ASME, International Gas Turbine and Aeroengine Congress and Exposition, The Hague, Netherlands, 1994. ...
Volume 6: Turbo Expo 2003, Parts A and B, 2003
A numerical model was included in a three-dimensional viscous solver to account for real gas effe... more A numerical model was included in a three-dimensional viscous solver to account for real gas effects in the compressible Reynolds Averaged Navier-Stokes (RANS) equations. The behavior of real gases is reproduced by using gas property tables. The method consists of a local ...
Volume 5: Turbo Expo 2002, Parts A and B, 2002
In the present paper, the flow structure inside a low-solidity diffuser of a transonic compressor... more In the present paper, the flow structure inside a low-solidity diffuser of a transonic compressor was investigated in detail. Steady computations were carried out and compared to experimental data. The secondary flow development inside the diffuser was analyzed and the reason ...
Volume 5: Turbo Expo 2004, Parts A and B, 2004
ABSTRACT
Volume 6: Oil and Gas Applications; Concentrating Solar Power Plants; Steam Turbines; Wind Energy, 2012
vol. 137, no.1, pp.012602 (9 pages), Jan 2015
This work deals with the influence of roughness on high-pressure steam turbine stages. It is divi... more This work deals with the influence of roughness on high-pressure steam turbine stages. It is divided in three parts. In the first one, an experimental campaign on a linear cascade is described, in which blade losses are measured for different values of surface roughness and in a range of Reynolds numbers of practical interest. The second part is devoted to the basic aspects of the numerical approach, and consists of a detailed discussion of the roughness models used for computations. The fidelity of such models is then tested against measurements, thus allowing their fine-tuning and proving their reliability. Finally, comprehensive CFD analysis is carried out on a high-pressure stage, in order to investigate the influence of roughness on the losses over the entire stage operating envelope. Unsteady effects that may affect the influence of the roughness, such as the upcoming wakes on the rotor blade, are taken into account, and the impact of transition-related aspects on the losses is discussed.
28th Joint Propulsion Conference and Exhibit, 1992
Navier-Stokes calculations were carried out in order to predict the heat-transfer rates on turbin... more Navier-Stokes calculations were carried out in order to predict the heat-transfer rates on turbine blades. The calculations were performed using TRAF2D which is a k-epsilon, explicit, finite volume mass-averaged Navier-Stokes solver. Turbulence was modeled using Coakley's ...
27th Joint Propulsion Conference, 1991
The three-dimensional Reynolds-averaged Navier-Stokes equations are numerically solved to obtain ... more The three-dimensional Reynolds-averaged Navier-Stokes equations are numerically solved to obtain the pressure distribution and heat transfer rates on the endwalls and the blades of two linear turbine cascades.
Volume 5: Turbo Expo 2002, Parts A and B, 2002
The aerodynamic redesign of an industrial transonic centrifugal impeller by means of CFD techniqu... more The aerodynamic redesign of an industrial transonic centrifugal impeller by means of CFD techniques is presented here. The computational procedure was validated by comparing numerical predictions of efficiency and work input coefficient to data from experimental ...
Volume 5: Turbo Expo 2004, Parts A and B, 2004
Numerical optimization techniques are increasingly used in the aerodynamic design of turbomachine... more Numerical optimization techniques are increasingly used in the aerodynamic design of turbomachine blades.
Volume 6: Turbomachinery, Parts A and B, 2006
A time-linearized quasi-3D solver for flutter analysis in turbomachinery flows was modified in or... more A time-linearized quasi-3D solver for flutter analysis in turbomachinery flows was modified in order to deal with incoming perturbations due to unsteady interactions with upstream/downstream rows. To do this, exact two-dimensional single-frequency non-reflecting boundary ...
Efficient acceleration techniques typical of explicit steady-state solvers are extended to time-a... more Efficient acceleration techniques typical of explicit steady-state solvers are extended to time-accurate calculations. Stability restrictions are greatly reduced by means of a fully implicit time discretization. A four-stage Runge-Kutta scheme with local time stepping, residual smoothing, and multigridding is used instead of traditional time-expensive factorizations. Some applications to natural and forced unsteady viscous flows show the capability of the procedure.
Rotor-stator interaction analysis using the Navier-Stokes equations and a multigrid method. Andre... more Rotor-stator interaction analysis using the Navier-Stokes equations and a multigrid method. Andrea Arnone, Roberto Pacciani AM SOC MECH ENG PAP, 15, 1995. A recently developed, time-accurate multigrid viscous solver ...
Transition modeling effects on turbine rotor blade heat transfer predictions. Ali A Ameri, Andrea... more Transition modeling effects on turbine rotor blade heat transfer predictions. Ali A Ameri, Andrea Arnone ASME, International Gas Turbine and Aeroengine Congress and Exposition, The Hague, Netherlands, 1994. The effect ...
Navier-Stokes calculations were carried out in order to predict the heat transfer rates on turbin... more Navier-Stokes calculations were carried out in order to predict the heat transfer rates on turbine blades. The calculations were performed using TRAF2D which is a two-dimensional, explicit, finite volume mass-averaged Navier-Stokes solver. Turbulence was modeled using q-omega and k-epsilon two-equation models and the Baldwin-Lomax algebraic model. The model equations along with the flow equations were solved explicitly on a non-periodic C grid. Implicit residual smoothing (IRS) or a combination of multigrid technique and IRS was applied to enhance convergence rates. Calculations were performed to predict the Stanton number distributions on the first stage vane and blade row as well as the second stage vane row of the Rocketdyne Space Shuttle Main Engine (SSME) high pressure fuel turbine. The comparison with the experimental results, although generally favorable, serves to highlight the weaknesses of the turbulence models and the possible areas of improving these models for use in tu...
The performance of a Low-Pressure Turbine (LPT) cascade were investigated under both steady and p... more The performance of a Low-Pressure Turbine (LPT) cascade were investigated under both steady and periodic unsteady inflow boundary conditions with different Reynolds numbers and a reduced frequency representative of real LPT working conditions. A sensitivity analysis to the variation of the inlet flow angle was performed to assess the performance during off-design operation. The numerical framework is based on a steady/unsteady Reynolds Averaged Navier-Stokes (RANS/URANS) flow solver which includes some state-of-the-art transition-sensitive turbulence closures. Boundary conditions for the time-accurate computations upstream of the cascade were derived from the experimental characterization of a moving bar system used to generate the wake periodic perturbations. The computed performance of the cascade, as a function of Reynolds number and incidence angle variation, is discussed in comparison with experimental data. Steady and unsteady boundary layer quantities are also compared with m...
This paper presents an efficient “Phase-Lagged” method developed for turbomachinery applications.... more This paper presents an efficient “Phase-Lagged” method developed for turbomachinery applications. The method is based on the Generalized-Shape-Correction model. Moving averages techniques as well as double-passage domain formulation were adopted in order to reduce memory requirements and improve the model robustness. The model was used to evaluate the aerodynamic performance of the high pressure transonic turbine stage CT3, experimentally studied at the von Karman Institute for Fluid Dynamics within the EU funded TATEF2 project. Results are discussed and compared with both the available experimental data and the results obtained by means of both steady and unsteady scaled Full-Annulus approaches. Computational requirements of the GSC model are evaluated and presented showing that nowadays unsteady results can be reached at an affordable computational cost.
The present activity was carried out in the framework of the Clean Sky European research project ... more The present activity was carried out in the framework of the Clean Sky European research project ITURB (”Optimal High-Lift Turbine Blade Aero-Mechanical Design”), aimed at designing and validating a turbine blade for a geared open rotor engine. A cold-flow, large-scale, low-speed (LS) rig was built in order to investigate and validate new design criteria, providing reliable and detailed results while containing costs. This paper presents the design of a LS stage, and describes a general procedure that allows to scale 3D blades for low-speed testing. The design of the stator row was aimed at matching the test-rig inlet conditions and at providing the proper inlet flow field to the blade row. The rotor row was redesigned in order to match the performance of the high-speed one, compensating for both the compressibility effects and different turbine flow paths. The proposed scaling procedure is based on the matching of the 3D blade loading distribution between the real engine environmen...
Volume 4: Heat Transfer; Electric Power; Industrial and Cogeneration, 1994
Prediction of turbine blade passage heat transfer using a zero and a two-equation turbulence mode... more Prediction of turbine blade passage heat transfer using a zero and a two-equation turbulence model. Ali A Ameri, Andrea Arnone ASME, International Gas Turbine and Aeroengine Congress and Exposition, The Hague, Netherlands, 1994. ...
Volume 6: Turbo Expo 2003, Parts A and B, 2003
A numerical model was included in a three-dimensional viscous solver to account for real gas effe... more A numerical model was included in a three-dimensional viscous solver to account for real gas effects in the compressible Reynolds Averaged Navier-Stokes (RANS) equations. The behavior of real gases is reproduced by using gas property tables. The method consists of a local ...
Volume 5: Turbo Expo 2002, Parts A and B, 2002
In the present paper, the flow structure inside a low-solidity diffuser of a transonic compressor... more In the present paper, the flow structure inside a low-solidity diffuser of a transonic compressor was investigated in detail. Steady computations were carried out and compared to experimental data. The secondary flow development inside the diffuser was analyzed and the reason ...
Volume 5: Turbo Expo 2004, Parts A and B, 2004
ABSTRACT
Volume 6: Oil and Gas Applications; Concentrating Solar Power Plants; Steam Turbines; Wind Energy, 2012
vol. 137, no.1, pp.012602 (9 pages), Jan 2015
This work deals with the influence of roughness on high-pressure steam turbine stages. It is divi... more This work deals with the influence of roughness on high-pressure steam turbine stages. It is divided in three parts. In the first one, an experimental campaign on a linear cascade is described, in which blade losses are measured for different values of surface roughness and in a range of Reynolds numbers of practical interest. The second part is devoted to the basic aspects of the numerical approach, and consists of a detailed discussion of the roughness models used for computations. The fidelity of such models is then tested against measurements, thus allowing their fine-tuning and proving their reliability. Finally, comprehensive CFD analysis is carried out on a high-pressure stage, in order to investigate the influence of roughness on the losses over the entire stage operating envelope. Unsteady effects that may affect the influence of the roughness, such as the upcoming wakes on the rotor blade, are taken into account, and the impact of transition-related aspects on the losses is discussed.
28th Joint Propulsion Conference and Exhibit, 1992
Navier-Stokes calculations were carried out in order to predict the heat-transfer rates on turbin... more Navier-Stokes calculations were carried out in order to predict the heat-transfer rates on turbine blades. The calculations were performed using TRAF2D which is a k-epsilon, explicit, finite volume mass-averaged Navier-Stokes solver. Turbulence was modeled using Coakley's ...
27th Joint Propulsion Conference, 1991
The three-dimensional Reynolds-averaged Navier-Stokes equations are numerically solved to obtain ... more The three-dimensional Reynolds-averaged Navier-Stokes equations are numerically solved to obtain the pressure distribution and heat transfer rates on the endwalls and the blades of two linear turbine cascades.
Volume 5: Turbo Expo 2002, Parts A and B, 2002
The aerodynamic redesign of an industrial transonic centrifugal impeller by means of CFD techniqu... more The aerodynamic redesign of an industrial transonic centrifugal impeller by means of CFD techniques is presented here. The computational procedure was validated by comparing numerical predictions of efficiency and work input coefficient to data from experimental ...