Physics-Based Part Orientation and Sentencing: A Solution to Manufacturing Variability

Author(s):  
Wen Yao Lee ◽  
William N. Dawes ◽  
John D. Coull

Abstract Casting deviations introduce geometric variability that impacts the aerodynamic performance of turbomachinery. These effects are studied for a High Pressure Turbine (HPT) rotor blade from a modern aero-engine. 197 blades were measured using three-dimensional structured-light scanning (GOM scanning), and the performance of each blade is quantified using Reynolds-Averaged Navier-Stokes (RANS) simulations. Casting variation is typically managed by applying geometric tolerances to determine the suitability of a component for service. The analysis demonstrates that this approach may not be optimal since it does not necessarily align with performance, in particular the capacity and efficiency. Alternatively, functional acceptance based on the predicted performance of each blade removes the uncertainty associated with geometric tolerancing and gives better performance control. Building on these findings, the paper proposes a method to set the orientation of the fir-tree, which is machined after casting. By customizing the alignment of each blade, performance variability and scrap rates can be significantly reduced. The method uses predictions of performance to reorient the castings to compensate for the manufacturing-induced errors, without changing the design-intent blade geometry and with minimal changes to the manufacturing facility.

2020 ◽  
Vol 142 (10) ◽  
Author(s):  
Wen Yao Lee ◽  
William N. Dawes ◽  
John D. Coull

Abstract Casting deviations introduce geometric variability that impacts the aerodynamic performance of turbomachinery. These effects are studied for a high-pressure turbine rotor blade from a modern aero-engine. A sample of 197 blades were measured using structured-light three-dimensional scanning, and the performance of each blade is quantified using Reynolds-averaged Navier–Stokes (RANS) simulations. Casting variation is typically managed by applying geometric tolerances to determine the suitability of a component for service. The analysis demonstrates that this approach may not be optimal since it does not necessarily align with performance, in particular the capacity and efficiency. Alternatively, functional acceptance based on the predicted performance of each blade removes the uncertainty associated with geometric tolerancing and gives better performance control. Building on these findings, the paper proposes a method to set the orientation of the fir-tree, which is machined after casting. By customizing the alignment of each blade, performance variability and scrap rates can be significantly reduced. The method uses predictions of performance to reorient the castings to compensate for manufacturing-induced errors, without changing the design-intent blade geometry and with minimal changes to the manufacturing facility.


Author(s):  
I. Sladojevic´ ◽  
E. P. Petrov ◽  
M. Imregun ◽  
A. I. Sayma

The paper presents the results of a study looking into changes in the forced response levels of bladed disc assemblies subject to both structural and aerodynamic mistuning. A whole annulus FE model, representative of a civil aero-engine fan with 26 blades was used in the calculations. The forced response of all blades of 1000 random mistuned patterns was calculated. The aerodynamic parameters, frequency shifts and damping, were calculated using a three-dimensional Reynolds-averaged Navier-Stokes aero-elasticity code. They were randomly varied for each mistuning pattern, with the assumption that the system would remain stable, i.e. flutter would not occur due to aerodynamic mistuning. The results show the variation of the forced response with different types of mistuning, with structural mistuning only, with aerodynamic mistuning only and with both structural and aerodynamic mistuning.


Author(s):  
Ioannis Templalexis ◽  
Pericles Pilidis ◽  
Geoffrey Guindeuil ◽  
Theodoros Lekas ◽  
Vassilios Pachidis

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.


2010 ◽  
Vol 133 (3) ◽  
Author(s):  
Alexios Zachariadis ◽  
Cesare A. Hall

This paper establishes a proven computational approach for open rotor configurations that can be used as a basis for further studies involving open rotor aerodynamics and design. Many of the difficulties encountered in the application of computational fluid dynamics to an open rotor engine arise due to the removal of the casing that is present in conventional aero-engine turbomachinery. In this work, an advanced three-dimensional Navier–Stokes solver is applied to the open rotor. The approach needed to accurately capture the aerodynamics is investigated with particular attention to the mesh configuration and the specification of the boundary conditions. A new three-step meshing strategy for generating the mesh and the most suitable type of far-field boundary condition are discussed. A control volume analysis approach is proposed for post-processing the numerical results for the rotor performance. The capabilities of the solver and the applied methodology are demonstrated at both cruise and take-off operating conditions. The comparison of the computational results with the experimental measurements shows good agreement for both data trend and magnitudes.


2020 ◽  
Vol 14 (4) ◽  
pp. 7369-7378
Author(s):  
Ky-Quang Pham ◽  
Xuan-Truong Le ◽  
Cong-Truong Dinh

Splitter blades located between stator blades in a single-stage axial compressor were proposed and investigated in this work to find their effects on aerodynamic performance and operating stability. Aerodynamic performance of the compressor was evaluated using three-dimensional Reynolds-averaged Navier-Stokes equations using the k-e turbulence model with a scalable wall function. The numerical results for the typical performance parameters without stator splitter blades were validated in comparison with experimental data. The numerical results of a parametric study using four geometric parameters (chord length, coverage angle, height and position) of the stator splitter blades showed that the operational stability of the single-stage axial compressor enhances remarkably using the stator splitter blades. The splitters were effective in suppressing flow separation in the stator domain of the compressor at near-stall condition which affects considerably the aerodynamic performance of the compressor.


Author(s):  
M. A. Abd Halim ◽  
N. A. R. Nik Mohd ◽  
M. N. Mohd Nasir ◽  
M. N. Dahalan

Induction system or also known as the breathing system is a sub-component of the internal combustion system that supplies clean air for the combustion process. A good design of the induction system would be able to supply the air with adequate pressure, temperature and density for the combustion process to optimizing the engine performance. The induction system has an internal flow problem with a geometry that has rapid expansion or diverging and converging sections that may lead to sudden acceleration and deceleration of flow, flow separation and cause excessive turbulent fluctuation in the system. The aerodynamic performance of these induction systems influences the pressure drop effect and thus the engine performance. Therefore, in this work, the aerodynamics of motorcycle induction systems is to be investigated for a range of Cubic Feet per Minute (CFM). A three-dimensional simulation of the flow inside a generic 4-stroke motorcycle airbox were done using Reynolds-Averaged Navier Stokes (RANS) Computational Fluid Dynamics (CFD) solver in ANSYS Fluent version 11. The simulation results are validated by an experimental study performed using a flow bench. The study shows that the difference of the validation is 1.54% in average at the total pressure outlet. A potential improvement to the system have been observed and can be done to suit motorsports applications.


AIAA Journal ◽  
1997 ◽  
Vol 35 ◽  
pp. 1089-1090
Author(s):  
B. Epstein ◽  
A. Jacobs ◽  
A. Nachshon

Author(s):  
Surabhi Rathore ◽  
Tomoki Uda ◽  
Viet Q. H. Huynh ◽  
Hiroshi Suito ◽  
Toshitaka Watanabe ◽  
...  

AbstractHemodialysis procedure is usually advisable for end-stage renal disease patients. This study is aimed at computational investigation of hemodynamical characteristics in three-dimensional arteriovenous shunt for hemodialysis, for which computed tomography scanning and phase-contrast magnetic resonance imaging are used. Several hemodynamical characteristics are presented and discussed depending on the patient-specific morphology and flow conditions including regurgitating flow from the distal artery caused by the construction of the arteriovenous shunt. A simple backflow prevention technique at an outflow boundary is presented, with stabilized finite element approaches for incompressible Navier–Stokes equations.


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