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Leading-edge receptivity for blunt-nose bodies
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Kerschen, Edward J. |
| Copyright Year | 1991 |
| Description | This research program investigates boundary-layer receptivity in the leading-edge region for bodies with blunt leading edges. Receptivity theory provides the link between the unsteady distrubance environment in the free stream and the initial amplitudes of the instability waves in the boundary layer. This is a critical problem which must be addressed in order to develop more accurate prediction methods for boundary-layer transition. The first phase of this project examines the effects of leading-edge bluntness and aerodynamic loading for low Mach number flows. In the second phase of the project, the investigation is extended to supersonic Mach numbers. Singular perturbation techniques are utilized to develop an asymptotic theory for high Reynolds numbers. In the first year, the asymptotic theory was developed for leading-edge receptivity in low Mach number flows. The case of a parabolic nose is considered. Substantial progress was made on the Navier-Sotkes computations. Analytical solutions for the steady and unsteady potential flow fields were incorporated into the code, greatly expanding the types of free-stream disturbances that can be considered while also significantly reducing the the computational requirements. The time-stepping algorithm was modified so that the potential flow perturbations induced by the unsteady pressure field are directly introduced throughout the computational domain, avoiding an artificial 'numerical diffusion' of these from the outer boundary. In addition, the start-up process was modified by introducing the transient Stokes wave solution into the downstream boundary conditions. |
| File Size | 997262 |
| Page Count | 26 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19910010734 |
| Archival Resource Key | ark:/13960/t15n14786 |
| Language | English |
| Publisher Date | 1991-04-01 |
| Access Restriction | Open |
| Subject Keyword | Aerodynamics High Reynolds Number Free Wing Aircraft Steady Flow Pressure Distribution Boundary Conditions Perturbation Unsteady Flow Potential Flow Algorithms Asymptotic Series Supersonic Speed Flow Distribution Boundary Layer Transition Free Flow Blunt Leading Edges Prediction Analysis Techniques Boundary Layers Aerodynamic Loads Mach Number Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Technical Report |
