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Secondary instabilities in compressible boundary layers
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Erlebacher, Gordon Ng, Lian |
| Copyright Year | 1990 |
| Description | Secondary instabilities are examined in compressible boundary layers at Mach numbers M(sub infinity) = 0, 0.8, 1.6, and 4.5. It is found that there is a broad-band of highly unstable 3-d secondary disturbances whose growth rates increase with increasing primary wave amplitude. At M(sub infinity) is less than or equal to 1.6, fundamental resonance dominates at relatively high (2-d) primary disturbance amplitude, while subharmonic resonance is characterized by a low (2-d) primary amplitude. At M(sub infinity) = 4.5, the subharmonic instability which arises from the second mode disturbance is the strongest type of secondary instability. The influence of the inclination, theta, of the primary wave with respect to the mean flow direction on secondary instability is investigated at M(sub infinity) = 1.6 for small to moderate values of theta. It is found that the strongest fundamental instability occurs when the primary wave is inclined at 10 deg to the mean flow direction, although a 2-d primary mode yields the most amplified subharmonic. The subharmonic instability at a high value of theta (namely, theta = 45 deg) is also discussed. Finally, a subset of the secondary instability results are compared against direct numerical simulations. |
| File Size | 1886684 |
| Page Count | 60 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19900019186 |
| Archival Resource Key | ark:/13960/t8vb32310 |
| Language | English |
| Publisher Date | 1990-09-01 |
| Access Restriction | Open |
| Subject Keyword | Aerodynamics Flow Stability Navier-stokes Equation Equations of State Broadband Compressible Boundary Layer Boundary Conditions Resonance Mathematical Models Mach Number Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
