Turbomachinery

About: Turbomachinery is a research topic. Over the lifetime, 6369 publications have been published within this topic receiving 78187 citations.

Computation of Unsteady Nonlinear Flows in Cascades Using a Harmonic Balance Technique

Abstract: A harmonic balance technique for modeling unsteady nonlinear e ows in turbomachinery is presented. The analysis exploits the fact that many unsteady e ows of interest in turbomachinery are periodic in time. Thus, the unsteady e ow conservation variables may be represented by a Fourier series in time with spatially varying coefe cients. This assumption leads to a harmonic balance form of the Euler or Navier ‐Stokes equations, which, in turn, can be solved efe ciently as a steady problem using conventional computational e uid dynamic (CFD) methods, including pseudotime time marching with local time stepping and multigrid acceleration. Thus, the method is computationally efe cient, at least one to two orders of magnitude faster than conventional nonlinear time-domain CFD simulations. Computational results for unsteady, transonic, viscous e ow in the front stage rotor of a high-pressure compressor demonstrate that even strongly nonlinear e ows can be modeled to engineering accuracy with a small number of terms retained in the Fourier series representation of the e ow. Furthermore, in some cases, e uid nonlinearities are found to be important for surprisingly small blade vibrations.

The Natural Excitation Technique (NExT) for modal parameter extraction from operating wind turbines

Abstract: The Natural Excitation Technique (NExT) is a method of modal testing that allows structures to be tested in their ambient environments This report is a compilation of developments and results since 1990, and contains a new theoretical derivation of NExT, as well as a verification using analytically generated data In addition, we compare results from NExT with conventional modal testing for a parked, vertical-axis wind turbine, and, for a rotating turbine, NExT is used to calculate the model parameters as functions of the rotation speed, since substantial damping is derived from the aeroelastic interactions during operation Finally, we compare experimental results calculated using NExT with analytical predictions of damping using aeroelastic theory

Fluid dynamics and heat transfer of turbomachinery

Abstract: Keywords: dynamique des : fluides ; transfert de chaleur ; turbomachines ; aerodynamique ; thermodynamique Reference Record created on 2005-11-18, modified on 2016-08-08

Turbomachinery Rotordynamics: Phenomena, Modeling, and Analysis

Abstract: Structural-Dynamic Models and Eigenanalysis for Undamped Flexible Rotors. Rotordynamic Introduction to Hydrodynamic Bearings and Squeeze-Film Dampers. Rotordynamic Models for Liquid Annular Seals. Rotordynamic Models for Annular Gas Seals. Rotordynamic Models for Turbines and Pump Impellers. Developing and Analyzing a System Rotordynamics Model. Example Rotor Analysis. Appendices. Index.

Rotordynamics of Turbomachinery

Abstract: Introduction. Rotordynamic Considerations in Turbomachinery Design. Torsional Vibration Analysis. Critical Speeds and Response to Imbalance. Rotor Balancing in Turbomachinery. Bearings and Seals. Rotordynamic Instability in Turbomachinery. Measurements.