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Systematic Investigation on Swept and Leaned Transonic Compressor Rotor Blades
Full text linkA systematic investigation to understand the impact of axial sweep and tangential lean on the aerodynamic behavior of transonic axial-flow compressor rotors was undertaken.
A commercial CFD package which solves the Reynolds-averaged Navier-Stokes equations was used to compute the complex flow field of these machines. The code was validated against NASA Rotor 37 existing experimental data. Computed performance maps and downstream profiles showed a good agreement with measured ones. Furthermore, comparisons with experimental data indicated that the overall features of three-dimensional shock structure, shock-boundary layer interaction, and tip clearance flows can be calculated well using the code.
Quite a large number of new transonic swept rotors (26) were modeled starting from the Rotor 37, by changing systematically the meridional curvature of the original stacking line using three previously defined control points. Similarly, 26 new transonic leaned rotors were modeled. All the new transonic rotors were simulated and numerical results revealed many interesting aspects which are believed to be very helpful to better understand the blade curvature effects on shock and secondary losses, giving insights on possible optimization techniques
Recent Advances in Transonic Axial Compressor Aerodynamics
No full textTransonic axial flow compressors are fundamental components in aircraft engines as they make it possible to maximize pressure ratios per stage unit. This is achieved through a careful combination of both tangential flow deflections and, above all, by taking advantage of shock wave formation around the rotor blades. The resulting flow field is really complex as it features highly three-dimensional inviscid/viscous structures, strong shock-boundary layer interaction and intense tip clearance effects which negatively influence compressor efficiency. Complications are augmented at part load operation, where stall - related phenomena occur. Therefore, considerable research efforts are being spent, both numerically and experimentally, to improve efficiency and stall margin at peak efficiency and near stall operation. The present work aims at giving a complete review of the most recent advances in the field of aerodynamic design and operation of such machines. A great emphasis has been given to highlight the most relevant contribution in this field and to suggest the prospects for future developments. © 2012 Elsevier Ltd
Aerodynamics of Swept and Leaned Transonic Compressor Rotors
No full textA systematic investigation to understand the impact of axially swept and tangentially leaned blades on the aerodynamic behaviour of transonic axial-flow compressorrotors was undertaken. Effects of axial and tangential blade curvature were analyzed separately. A commercial CFD package, which solves the Reynolds-averaged Navier–Stokes equations, was used to compute the complex flow field of transoniccompressor-rotors. It was validated against NASA Rotor 37 existing experimental data. Computed performance maps and downstream profiles showed a good agreement with measured ones. Furthermore, comparisons with experimental data indicated that the overall features of three-dimensional shock structure, shock-boundary layer interaction, and wake development are calculated well by the numerical solution. Next, quite a large number of new transonicsweptrotors (26) were modelled from the original Rotor 37, by changing the meridional curvature of the original stacking line through three previously defined control points (located at 33%, 67% and 100% of span). Similarly, 26 new transonicleanedrotors were modelled by changing the circumferential position of the same control points. All the new transonicrotors were simulated and the results revealed many interesting aspects which are believed to be very helpful to better understand the blade curvature effects on shock structure and secondary losses within a transonicrotor
Development of a Transonic Compressor Test Facility
No full textPROCEEDINGS OF THE ECOS2008, 21ST INTERNATIONAL CONFERENCE ON EFFICIENCY, COST, OPTIMIZATION, SIMULATION AND ENVIRONMENTAL IMPACT OF ENERGY SYSTEMS, JUNE 24 – 27, 2008, KRAKÓW, POLAND
Validation of a Navier-Stokes Solver for CFD Computations of Transonic Compressors
No full textThe progress of numerical methods and computing facilities has led to using Computational Fluid Dynamics (CFD) as a current tool for designing components of gas turbine engines. It is known, however, that a sophisticated numerical model is required to well reproduce the many complex flow phenomena which characterize compression systems, such as shock waves and their interactions with boundary layers and tip clearance flows.
In this work, the flow field inside the NASA Rotor 37, a well known test case representative of complex three-dimensional viscous flow structures in transonic bladings, was simulated using a commercial CFD code based on the 3-D Reynolds-averaged Navier-Stokes equations. In order to improve the accuracy of predictions, different aspects of the numerical model were analyzed; in particular, an attempt was made to understand the influence of grid topology, number of nodes and their distribution, turbulence model, and discretization scheme of numerical solution on the accuracy of computed results. Existing experimental data were used to assess the quality of the solutions. The obtainment of a good agreement between computed and measured performance maps and downstream profiles was clearly shown. Also, detailed comparison with experimental results indicated that the overall features of the three-dimensional shock structure, the shock-boundary layer interaction, and the wake development can be calculated very well in the numerical approach for all the operating conditions.
The possibility of a numerical model as a valid tool to better understand the aerodynamic behaviour of existing transonic compressors and to design new ones was demonstrated. It was also pointed out that the development of an accurate model requires the knowledge of both the physical phenomena involving the flow field and the features of the code which model them
Shock-Boundary Layer-Tip Clearance Interaction in a Three-Dimensional Shaped Transonic Rotor Blade
No full textA newly designed rotor was modeled from the well-known radially stacked NASA rotor 37 by applying a three-dimensional shape to the original blade stacking line. A considerable curvature toward the direction of rotor rotation was given to the new blade. A three-dimensional numerical model, developed and validated using a commercial computational fluid dynamics Reynolds-averaged Navier―Stokes code, was adopted to predict the flowfield inside the new rotor. Steady-viscous-flow calculations were run at the design speed of the baseline configuration. Compared with rotor 37, the new rotor showed a higher efficiency, mainly due to a three-dimensional modification of the shock structure. At the outer span, the new rotor developed a blade-to-blade shock front located more downstream than in the baseline rotor, with a considerable impact on the flowfield near the casing. Computational fluid dynamics flow visualizations showed a less detrimental shock/boundary-layer/tip-clearance interaction at low-flow operating conditions, with a considerable reduction of the low-momentum-fluid region after the shock
Impact of Aerodynamic Sweep and Lean on the Structural Behaviour of a Transonic Rotor Blade
No full text11-12 OCTOBER – BRUSSELS
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