Modeling of Unsteady ThreeDimensional Flows in Multistage Machines
Abstract
Despite many years of development, the accurate and reliable prediction of unsteady aerodynamic forces acting on turbomachinery blades remains less than satisfactory, especially when viewed next to the great success investigators have had in predicting steady flows. Hall and Silkowski (1997) have proposed that one of the main reasons for the discrepancy between theory and experiment and/or industrial experience is that many of the current unsteady aerodynamic theories model a single blade row in an infinitely long duct, ignoring potentially important multistage effects. However, unsteady flows are made up of acoustic, vortical, and entropic waves. These waves provide a mechanism for the rotors and stators of multistage machines to communicate with one another. In other words, wave behavior makes unsteady flows fundamentally a multistage (and threedimensional) phenomenon. In this research program, we have has as goals (1) the development of computationally efficient computer models of the unsteady aerodynamic response of blade rows embedded in a multistage machine (these models will ultimately be capable of analyzing threedimensional viscous transonic flows), and (2) the use of these computer codes to study a number of important multistage phenomena.
 Publication:

NASA STI/Recon Technical Report N
 Pub Date:
 January 2003
 Bibcode:
 2003STIN...0314839H
 Keywords:

 Unsteady Flow;
 Unsteady Aerodynamics;
 Turbomachinery;
 Applications Programs (Computers);
 Three Dimensional Flow;
 Three Dimensional Models;
 Computational Fluid Dynamics;
 Heat Transfer;
 Rotor Blades (Turbomachinery);
 Ducts;
 NavierStokes Equation;
 Statistical Analysis;
 Fluid Mechanics and Thermodynamics