scholarly journals A Unified Geometry Parametrization Method for Turbomachinery Blades

2021 ◽  
pp. 102987
Author(s):  
Roberto Agromayor ◽  
Nitish Anand ◽  
Jens-Dominik Müller ◽  
Matteo Pini ◽  
Lars O. Nord
Keyword(s):  
Parametrization Method ◽  
Turbomachinery Blades

Aerodynamic Asymmetry Analysis of Unsteady Flows in Turbomachinery

2009 ◽  
Vol 132 (1) ◽  
Author(s):  
Kivanc Ekici ◽  
Robert E. Kielb ◽  
Kenneth C. Hall
Keyword(s):  
Harmonic Balance ◽  
Coupling Effect ◽  
Unsteady Flows ◽  
Unsteady Aerodynamic ◽  
Blade Row ◽  
Balance Technique ◽  
Turbomachinery Blades ◽  
Aerodynamic Asymmetry ◽  
Frequency Domain Approach ◽  
Harmonic Balance Technique

A nonlinear harmonic balance technique for the analysis of aerodynamic asymmetry of unsteady flows in turbomachinery is presented. The present method uses a mixed time-domain/frequency-domain approach that allows one to compute the unsteady aerodynamic response of turbomachinery blades to self-excited vibrations. Traditionally, researchers have investigated the unsteady response of a blade row with the assumption that all the blades in the row are identical. With this assumption the entire wheel can be modeled using complex periodic boundary conditions and a computational grid spanning a single blade passage. In this study, the steady/unsteady aerodynamic asymmetry is modeled using multiple passages. Specifically, the method has been applied to aerodynamically asymmetric flutter problems for a rotor with a symmetry group of 2. The effect of geometric asymmetries on the unsteady aerodynamic response of a blade row is illustrated. For the cases investigated in this paper, the change in the diagonal terms (blade on itself) dominated the change in stability. Very little mode coupling effect caused by the off-diagonal terms was found.

A Three-Dimensional Viscous Transonic Inverse Design Method

2000 ◽  
Author(s):  
W. T. Tiow ◽  
M. Zangeneh
Keyword(s):  
Design Method ◽  
Flow Analysis ◽  
Three Dimensional ◽  
Viscous Effects ◽  
Flow Equations ◽  
Flow Solution ◽  
Turbomachinery Blades ◽  
A Cell ◽  
Inverse Design Method ◽  
Euler Solver

The development and application of a three-dimensional inverse methodology is presented for the design of turbomachinery blades. The method is based on the mass-averaged swirl, rV~θ distribution and computes the necessary blade changes directly from the discrepancies between the target and initial distributions. The flow solution and blade modification converge simultaneously giving the final blade geometry and the corresponding steady state flow solution. The flow analysis is performed using a cell-vertex finite volume time-marching algorithm employing the multistage Runge-Kutta integrator in conjunction with accelerating techniques (local time stepping and grid sequencing). To account for viscous effects, dissipative forces are included in the Euler solver using the log-law and mixing length models. The design method can be used with any existing solver solving the same flow equations without any modifications to the blade surface wall boundary condition. Validation of the method has been carried out using a transonic annular turbine nozzle and NASA rotor 67. Finally, the method is demonstrated on the re-design of the blades.

Aerodynamic Asymmetry Analysis of Unsteady Flows in Turbomachinery

2008 ◽  
Author(s):  
Kivanc Ekici ◽  
Robert E. Kielb ◽  
Kenneth C. Hall
Keyword(s):  
Harmonic Balance ◽  
Coupling Effect ◽  
Unsteady Flows ◽  
Unsteady Aerodynamic ◽  
Blade Row ◽  
Balance Technique ◽  
Turbomachinery Blades ◽  
Aerodynamic Asymmetry ◽  
Frequency Domain Approach ◽  
Harmonic Balance Technique

A nonlinear harmonic balance technique for the analysis of aerodynamic asymmetry of unsteady flows in turbomachinery is presented. The present method uses a mixed time-domain/frequency-domain approach that allows one to compute the unsteady aerodynamic response of turbomachinery blades to self-excited vibrations. Traditionally, researchers have investigated the unsteady response of a blade row with the assumption that all the blades in the row are identical. With this assumption the entire wheel can be modeled using complex periodic boundary conditions and a computational grid spanning a single blade passage. In this study, the steady/unsteady aerodynamic asymmetry is modeled using multiple passages. Specifically, the method has been applied to aerodynamically asymmetric flutter problems for a rotor with a symmetry group of two. The effect of geometric asymmetries on the unsteady aerodynamic response of a blade row is illustrated. For the cases investigated in this paper, the change in the diagonal terms (blade on itself) dominated the change in stability. Very little mode coupling effect caused by the off-diagonal terms was found.

scholarly journals Transition Prediction in Attached and Separated Shear Layers Using an Integral Method

1992 ◽  
Author(s):  
G. Leoutsakos ◽  
K. D. Papailiou
Keyword(s):  
Integral Method ◽  
Adverse Pressure Gradient ◽  
Shear Layers ◽  
Separated Flows ◽  
Prediction Methods ◽  
Accurate Assessment ◽  
Transition Prediction ◽  
Turbomachinery Blades ◽  
Aerodynamic Parameters ◽  
Work Done

Calculation of the aerodynamic parameters of axial turbomachinery blades, and an accurate assessment of the flow over the blade surfaces under today’s increasingly demanding requirements for higher efficiencies and optimized blade shapes, at both design and off-design conditions, impose a need for accurate prediction methods able to compute through two sensitive but highly critical phenomena: separation and transition. The present study describes work done on the modelling and prediction of transitional regions, such as those appearing on turbomachinery blading, covering both attached and separated flows. The concept of an engineering method, cheap to run and avoiding complex CFD and turbulence model formulations was always kept in mind. Results include comparisons of integral quantities and velocity profiles in zero, favourable or adverse pressure gradient attached flows, and velocity distributions including points of separation, transition and reattachment in separated airfoil flows, obtained either from a straightforward shear layer calculation or from a viscous-inviscid interaction procedure.

scholarly journals BladeCAD: An Interactive Geometric Design Tool for Turbomachinery Blades

1996 ◽  
Author(s):  
Perry L. Miller ◽  
James H. Oliver ◽  
David P. Miller ◽  
Daniel L. Tweedt
Keyword(s):  
Design Tool ◽  
Software Implementation ◽  
Blade Design ◽  
Nurbs Surface ◽  
Surfaces Of Revolution ◽  
B Spline ◽  
Turbomachinery Blades ◽  
Flow Through ◽  
Manufacturing Applications ◽  
Primary Contribution

A new methodology for interactive design of turbomachinery blades is presented. Software implementation of the methods provides a user interface that is intuitive to aero-designers while operating with standardized geometric forms. The primary contribution is that blade sections may be defined with respect to general surfaces of revolution which may be defined to represent the path of fluid flow through the turbomachine. The completed blade design is represented as a non-uniform rational B-spline (NURBS) surface and is written to a standard IGES file which is portable to most design, analysis, and manufacturing applications.

Prediction of Aerodynamically Induced Blade Vibrations in a Radial Turbine Rotor Using the Nonlinear Harmonic Approach

2018 ◽  
Author(s):  
Nikola Kovachev ◽  
Christian U. Waldherr ◽  
Jürgen F. Mayer ◽  
Damian M. Vogt
Keyword(s):  
Structural Model ◽  
Measurement Data ◽  
Turbine Rotor ◽  
Forced Response ◽  
Response Analysis ◽  
Blade Vibration ◽  
Computational Costs ◽  
Alternative Approach ◽  
Turbomachinery Blades ◽  
Predicted Values

Resonant response of turbomachinery blades can lead to high cycle fatigue (HCF) if the vibration amplitudes are excessive. Accurate and reliable simulations of the forced response phenomenon require detailed CFD and FE models that may consume immense computational costs. In the present study, an alternative approach is applied, which incorporates nonlinear harmonic (NLH) CFD simulations in a one-way fluid-structure interaction (FSI) workflow for the prediction of the forced response phenomenon at reduced computational costs. Five resonance crossings excited by the stator in a radial inflow turbocharger turbine are investigated and the aerodynamic excitation and damping are predicted using this approach. Blade vibration amplitudes are obtained from a subsequent forced response analysis combining the aerodynamic excitation with aerodynamic damping and a detailed structural model of the investigated turbine rotor. A comparison with tip timing measurement data shows that all predicted values lay within the range of the mistuned blade response underlining the high quality of the utilized workflow.

An improved aerodynamic performance optimization method of 3-D low Reynolds number rotor blade

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Shuyi Zhang ◽  
Bo Yang
Keyword(s):  
Neural Network ◽  
Reynolds Number ◽  
Performance Optimization ◽  
Rotor Blade ◽  
Optimization Method ◽  
Aerodynamic Performance ◽  
Aerodynamic Optimization ◽  
Parametrization Method ◽  
Value Evaluation ◽  
Fitness Value

Abstract In this paper, an improved aerodynamic performance optimization method for 3-D low Reynolds number (Re) rotor blade is proposed. A conventional optimization procedure of blade is usually divided into three parts, such as the parameterization method, the fitness value evaluation and the optimization algorithm. This work is mainly focused on the first two parts. The parametrization method, Camber-FFD, is presented based on the camber parametrization method and the free-form deformation algorithm (FFD). The shape of 3-D blade is parameterized by the incidence angles and the coordinates of the maximum camber points. The fitness value evaluation has been realized with the help of an adaptive topological back propagation multi-layer forward artificial neural network (BP-MLFANN). During the training of BP-MLFANN, the hybrid particle swarm optimization method combined with the modified very fast simulate annealing algorithm (HPSO-MVFSA) is adopted to determine the neural network topology adaptively. To verify the effectiveness of this aerodynamic optimization method, the aerodynamic performance of a 3-D low-Re blade, such as Blade D900, is optimized, and the results are compared and analyzed based on the experiments and simulations. It is proved that this aerodynamic optimization method is feasible.

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