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Optimal disturbances in boundary layers subject to streamwise pressure gradient (Document No: 20030062175)
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Tumin, Anatoli Ashpis, David E. |
| Copyright Year | 2003 |
| Description | An analysis of the non-modal growth of perturbations in a boundary layer in the presence of a streamwise pressure gradient is presented. The analysis is based on PSE equations for an incompressible fluid. Examples with Falkner- Skan profiles indicate that a favorable pressure gradient decreases the non-modal growth while an unfavorable pressure gradient leads to an increase of the amplification. It is suggested that the transient growth mechanism be utilized to choose optimal parameters of tripping elements on a low-pressure turbine (LPT) airfoil. As an example, a boundary-layer flow with a streamwise pressure gradient corresponding to the pressure distribution over a LPT airfoil is considered. It is shown that there is an optimal spacing of the tripping elements and that the transient growth effect depends on the starting point. The amplification is found to be small at the LPT s very low Reynolds numbers, but there is a possibility to enhance the transient energy growth by means of wall cooling. |
| File Size | 312553 |
| Page Count | 13 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_20030062175 |
| Archival Resource Key | ark:/13960/t8hf2sm5w |
| Language | English |
| Publisher Date | 2003-05-01 |
| Access Restriction | Open |
| Subject Keyword | Fluid Mechanics And Thermodynamics Amplification Low Reynolds Number Pressure Distribution Airfoils Perturbation Turbines Boundary Layers Incompressible Fluids Pressure Gradients 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 |
