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Unsteady pressures in a transonic fan cascade due to a single oscillating airfoil
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Capece, V. R. McFarland, E. R. Hayden, J. Lepicovsky, J. |
| Copyright Year | 2002 |
| Description | An extensive set of unsteady pressure data was acquired along the midspan of a modern transonic fan blade for simulated flutter conditions. The data set was acquired in a nine-blade linear cascade with an oscillating middle blade to provide a database for the influence coefficient method to calculate instantaneous blade loadings. The cascade was set for an incidence of 10 dg. The data were acquired on three stationary blades on each side of the middle blade that was oscillated at an amplitude of 0.6 dg. The matrix of test conditions covered inlet Mach numbers of 0.5, 0.8, and 1.1 and the oscillation frequencies of 200, 300, 400, and 500 Hz. A simple quasiunsteady two-dimensional computer simulation was developed to aid in the running of the experimental program. For high Mach number subsonic inlet flows the blade pressures exhibit very strong, low-frequency, self-induced oscillations even without forced blade oscillations, while for low subsonic and supersonic inlet Mach numbers the blade pressure unsteadiness is quite low. The amplitude of forced pressure fluctuations on neighboring stationary blades strongly depends on the inlet Mach number and forcing frequency. The flowfield behavior is believed to be governed by strong nonlinear effects due to a combination of viscosity, compressibility, and unsteadiness. Therefore, the validity of the quasi-unsteady simplified computer simulation is limited to conditions when the flowfield is behaving in a linear, steady manner. Finally, an extensive set of unsteady pressure data was acquired to help development and verification of computer codes for blade flutter effects. |
| File Size | 1558848 |
| Page Count | 17 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_20020081292 |
| Archival Resource Key | ark:/13960/t3gx9887z |
| Language | English |
| Publisher Date | 2002-07-01 |
| Access Restriction | Open |
| Subject Keyword | Aircraft Propulsion And Power Computational Fluid Dynamics Data Acquisition Pressure Oscillations Airfoils Computerized Simulation Inlet Flow Data Reduction Fan Blades Influence Coefficient Oscillating Flow Cascade Flow Subsonic Flow Flow Distribution Low Frequencies Mach Number Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Technical Report |
