Influence of Upstream and Downstream Stator Blades on the Rotor Blade Flutter Characteristics

2018 ◽  
Author(s):  
Zhang Xiaojie ◽  
Wang Yanrong ◽  
Han Le ◽  
Zhao Jiazhe ◽  
Luo Yanbin
Keyword(s):  
Rotor Blade ◽  
Systematic Research ◽  
Plane Method ◽  
Aerodynamic Damping ◽  
Flutter Analysis ◽  
Blade Flutter ◽  
Time Marching ◽  
Mp Method ◽  
Marching Method ◽  
Rotor Model

One of the important issues in turbomachinery flutter analysis is the intra-row interaction effects. The present work is aimed at a systematic research of the adjacent rows effects on aerodynamic damping. Three models, the isolated rotor, the IGV-rotor and the rotor-stator model, are performed to identify the upstream and downstream stator effects on the rotor blade. It is found that the aerodynamic damping from the stage flutter simulations are quite different from that from isolated rotor. In addition, the mixing-plane method is also applied to calculate the stage flutter characteristics and its accuracy of flutter predictions is compared with the time-marching method. It is indicated that the main difference of aerowork density between MP and TM is in the tip area, and in some cases the result from MP method can be misleading. Furthermore, study with different axial gaps illustrates that there is a nonmonotonic relationship between the rotor blade aerodynamic damping and the gap in the rotor-stator model, while the rotor blade aerodynamic damping monotonically increases with the gap in the IGV-rotor model.

Calculation of the Quasi Three-Dimensional Flow in a Turbomachine Blade Row

1977 ◽  
Vol 99 (1) ◽  
pp. 53-62 ◽  
Author(s):  
Jean-Pierre Veuillot
Keyword(s):  
Finite Difference ◽  
Three Dimensional ◽  
Three Dimensional Flow ◽  
Through Flow ◽  
Blade Row ◽  
Time Marching ◽  
Space Discretization ◽  
Finite Volume Approach ◽  
Marching Method ◽  
Finite Difference Techniques

The equations of the through flow are obtained by an asymptotic theory valid when the blade pitch is small. An iterative method determines the meridian stream function, the circulation, and the density. The various equations are discretized in an orthogonal mesh and solved by classical finite difference techniques. The calculation of the steady transonic blade-to-blade flow is achieved by a time marching method using the MacCormack scheme. The space discretization is obtained either by a finite difference approach or by a finite volume approach. Numerical applications are presented.

Flutter Analysis of a Flexible UHBR Fan at Different Flight Conditions

2018 ◽  
Author(s):  
Matthias Schuff ◽  
Jannik Reisberg
Keyword(s):  
Aerodynamic Characteristics ◽  
Aeroelastic Stability ◽  
Aerodynamic Damping ◽  
Aerodynamic Loading ◽  
Similarity Principle ◽  
Flutter Analysis ◽  
Effective Angle ◽  
Inlet Conditions ◽  
Compressor Map ◽  
Operating Points

A flexible UHBR fan is investigated at different flight conditions with a focus on static deflections and aeroelastic stability. Operating points at varying inlet conditions, which are comparable according to the Mach similarity principle, are investigated. However, not all the aerodynamic characteristics remain identical and aerodynamic damping of mode shape vibrations is changed. When steady deformations of the fan blades are taken into account, the deviation between different inlet conditions increases further. This is mainly due to torsional deflections, changing the effective angle of attack and causing a general shift of the compressor map. Even though the subsequent changes in flutter predictions are not severe for most parts of the compressor map, the behavior at the boundaries is sensitive to the real flight condition. As shown, the Mach similarity principle is not suitable for investigating aeroelastic stability throughout the whole flight envelope, especially when the static blade deformation is not neglectable. The reason for this can be found in the complex interaction between dimension-less numbers (Mach, Reynolds), sized values (pressure difference or aerodynamic loading, natural frequency) and their dependency on each other.

On the Use of Direct and Inverse Numerical Flow Calculations for Supersonic Turbine Design

1994 ◽  
Author(s):  
F. Pommel
Keyword(s):  
Flow Field ◽  
Euler Equations ◽  
Velocity Component ◽  
Normal Velocity ◽  
Blade Design ◽  
Blade Profile ◽  
Flow Solver ◽  
Time Marching ◽  
Turbine Design ◽  
Marching Method

A procedure for blade design, using a time marching method to solve the Euler equations in the blade-to-blade plane is presented. This procedure uses an Office Nationale d’Etude et de Recherches Aeronautique flow solver. The classical slip conditions (no normal velocity component along the blade profile) has been replaced by another boundary conditions in such a way that the required pressure may be imposed directly. The orignal direct code was therefore transformed into an inverse solver. The unknows are calculated on the blade wall using the so-called compatibility relations. The blade geometry is then modified by resetting the wall parallel to the new flow field. The results obtained with this design process for a supersonic turbine blade of a space turbopump is presented.

A Time Marching Method for Internal Flows Using Curvilinear Coordinates

1986 ◽  
Vol 10 (1) ◽  
pp. 8-15
Author(s):  
M. Reggio ◽  
R. Camarero
Keyword(s):  
Gas Dynamics ◽  
Curvilinear Coordinates ◽  
System Stability ◽  
Internal Flows ◽  
Axisymmetric Nozzle ◽  
Equations Of Gas Dynamics ◽  
Curvilinear Grid ◽  
Momentum Fluxes ◽  
Time Marching ◽  
Marching Method

A time-marching method for flows with nozzle and blade-to-blade applications is presented. The approach developed consists of solving the basic conservation equations of gas dynamics in conservation form on a curvilinear grid. The assumption of quasi-streamlines is satisfied by generating a body-fitted coordinate system. Stability is maintained by upwind differencing of the mass and momentum fluxes and downwind differencing of the pressure. The method is then applied to the solution of a plane and axisymmetric nozzle and to VKI’s gas turbine blade and compared to previous computations and experiments.

An examination of the Throughflow of Nucleating Steam in a Turbine Stage by a Time-Marching Method

1989 ◽  
Vol 203 (4) ◽  
pp. 233-243 ◽  
Author(s):  
F Bakhtar ◽  
B O Bamkole
Keyword(s):  
Computer Program ◽  
Thermodynamic Equilibrium ◽  
Theoretical Treatment ◽  
Test Cases ◽  
Turbine Stage ◽  
Conservation Equations ◽  
Time Marching ◽  
Marching Method ◽  
Non Equilibrium

The paper describes a theoretical treatment for nucleating throughflow of steam in a turbine stage. The conservation equations governing the overall behaviour of the fluid are combined with those describing droplet behaviour and treated by a time-marching method. The computer program developed has been applied to some test cases and comparisons are presented between solutions allowing for non-equilibrium effects and those in which steam has been assumed to remain in thermodynamic equilibrium.

Advances in fan and compressor blade flutter analysis and predictions

1975 ◽  
Vol 12 (4) ◽  
pp. 325-332 ◽  
Author(s):  
A. A. Mikolajczak ◽  
R. A. Arnoldi ◽  
L. E. Snyder ◽  
H. Stargardter
Keyword(s):  
Compressor Blade ◽  
Flutter Analysis ◽  
Blade Flutter
Sign in / Sign up

Export Citation Format

Share Document