Acoustic-Wave/Blade-Row Interactions Establish Boundary Conditions for Unsteady Inlet Flows

2001 ◽  
Vol 17 (5) ◽  
pp. 1090-1099 ◽  
Author(s):  
Miklos Sajben ◽  
Hazem Said
Keyword(s):  
Acoustic Wave ◽  
Boundary Conditions ◽  
Blade Row

scholarly journals The Computation of Adjacent Blade-Row Effects in a 1.5 Stage Axial Flow Turbine

1997 ◽  
Author(s):  
Rolf Emunds ◽  
Ian K. Jennions ◽  
Dieter Bohn ◽  
Jochen Gier
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Boundary Conditions ◽  
Axial Flow ◽  
The Other ◽  
Navier Stokes ◽  
Blade Row ◽  
Flow Through ◽  
The University

This paper deals with the numerical simulation of flow through a 1.5 stage axial flow turbine. The 3-row configuration has been experimentally investigated at the University of Aachen where measurements behind the first vane, the first stage and the full configuration were taken. These measurements allow single blade row computations, to the measured boundary conditions taken from complete engine experiments, or full multistage simulations. The results are openly available inside the framework of ERCOFTAC 1996. There are two separate but interrelated parts to the paper. Firstly, two significantly different Navier-Stokes codes are used to predict the flow around the first vane and the first rotor, both running in isolation. This is used to engender confidence in the code that is subsequently used to model the multiple bladerow tests, the other code is currently only suitable for a single blade row. Secondly, the 1.5 stage results are compared to the experimental data and promote discussion of surrounding blade row effects on multistage solutions.

Effect of Bleed Flows on Flutter and Forced Response of Core Compressors

2006 ◽  
Author(s):  
Luca di Mare ◽  
George Simpson ◽  
Bernhard Mueck ◽  
Abdulnaser I. Sayma
Keyword(s):  
Boundary Conditions ◽  
Flow Pattern ◽  
Forced Response ◽  
Accurate Prediction ◽  
Aeroelastic Response ◽  
Axial Compressors ◽  
Blade Row

This paper presents a methodology for the modeling of flutter and forced response in axial compressors while taking into account the effect of bleed off-takes. Usually, aeroelasticity analyses are performed assuming smooth solid end walls. This type of analysis has two main shortcomings. Firstly, it does not account for the change in the aerodynamic speed of the stages downstream of the bleed off-take, so that aeroelasticity analyses are not performed at the correct aerodynamic conditions. Secondly, bleed off-takes influence the flow pattern particularly in the stages around or close to the bleed off-take, thus leading to possibility of obtaining the wrong aeroelastic response. Another objective of this paper is to present a methodology for the accurate prediction of the flow in a compressor with bleed off-take, by both including the geometry of the bleed off-take and performing the calculations on the entire compressor, thus eliminating errors resulting from prescribing boundary conditions at inter-blade row boundaries. It is concluded that bleed off-takes could influence significantly the aeroelastic response of the blades.

The Simulation of Turbomachinery Blade Rows in Asymmetric Flow Using Actuator Disks

1997 ◽  
Vol 119 (4) ◽  
pp. 723-732 ◽  
Author(s):  
W. G. Joo ◽  
T. P. Hynes
Keyword(s):  
Supersonic Flow ◽  
Flow Field ◽  
Boundary Conditions ◽  
High Speed ◽  
Axial Position ◽  
Numerical Implementation ◽  
Asymmetric Flow ◽  
Actuator Disk ◽  
Blade Row ◽  
Flow Through

This paper describes the development of actuator disk models to simulate the asymmetric flow through high-speed low hub-to-tip ratio blade rows. The actuator disks represent boundaries between regions of the flow in which the flow field is solved by numerical computation. The appropriate boundary conditions and their numerical implementation are described, and particular attention is paid to the problem of simulating the effect of blade row blockage near choking conditions. Guidelines on choice of axial position of the disk are reported. In addition, semi-actuator disk models are briefly described and the limitations in the application of the model to supersonic flow are discussed.

scholarly journals NUMERICAL SIMULATION OF THE ACOUSTIC WAVE REFLECTION FROM A ROTATING BLADE ROW

2018 ◽  
pp. 5-15 ◽  
Author(s):  
Nikolay Shuvaev ◽  
◽  
Aleksandr Siner ◽  
Nikita Bolshagin ◽  
Ruslan Kolegov ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Acoustic Wave ◽  
Wave Reflection ◽  
Rotating Blade ◽  
Blade Row

BULK AND SURFACE ACOUSTIC WAVES IN ANISOTROPIC SOLIDS

2000 ◽  
Vol 10 (03) ◽  
pp. 653-684 ◽  
Author(s):  
ERIC L. ADLER
Keyword(s):  
Acoustic Wave ◽  
Boundary Conditions ◽  
Surface Acoustic Wave ◽  
Acoustic Waves ◽  
Surface Acoustic Waves ◽  
Guided Wave ◽  
Symmetry Properties ◽  
Interface Boundary Conditions ◽  
Matrix Differential ◽  
The Individual

In this paper methods for analyzing acoustic propagation characteristics for bulk and surface acoustic waves in anisotropic piezoelectric multilayers are described. The methods's conceptual usefulness is demonstrated by examples showing how problems of guided wave propagation in complicated layered surface acoustic wave device geometries are simplified. The formulation reduces the acoustoelectric equations to a first order ordinary matrix differential equation in the variables that must be continuous across interfaces. The solution to these equations is a transmission matrix that maps the variables from one layer face to the other. Interface boundary conditions for a planar multilayer are automatically satisfied by multiplying the individual transmission matrices in the appropriate order thus reducing the problem to imposing boundary conditions appropriate to the remaining free surface. The dimensionality of the problem being independent of the number of layers is a significant advantage. A classification scheme for reducing problem dimensionality, based on an understanding of crystal symmetry properties, further simplifies surface acoustic wave problems.

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