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A real-time method for estimating viscous forebody drag coefficients
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Hurtado, Marco Whitmore, Stephen A. Naughton, Jonathan W. Rivera, Jose |
| Copyright Year | 2000 |
| Description | This paper develops a real-time method based on the law of the wake for estimating forebody skin-friction coefficients. The incompressible law-of-the-wake equations are numerically integrated across the boundary layer depth to develop an engineering model that relates longitudinally averaged skin-friction coefficients to local boundary layer thickness. Solutions applicable to smooth surfaces with pressure gradients and rough surfaces with negligible pressure gradients are presented. Model accuracy is evaluated by comparing model predictions with previously measured flight data. This integral law procedure is beneficial in that skin-friction coefficients can be indirectly evaluated in real-time using a single boundary layer height measurement. In this concept a reference pitot probe is inserted into the flow, well above the anticipated maximum thickness of the local boundary layer. Another probe is servomechanism-driven and floats within the boundary layer. A controller regulates the position of the floating probe. The measured servomechanism position of this second probe provides an indirect measurement of both local and longitudinally averaged skin friction. Simulation results showing the performance of the control law for a noisy boundary layer are then presented. |
| File Size | 1620295 |
| Page Count | 33 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_20000011505 |
| Archival Resource Key | ark:/13960/t9r25wc1v |
| Language | English |
| Publisher Date | 2000-01-01 |
| Access Restriction | Open |
| Subject Keyword | Aircraft Design, Testing And Performance Controllers Aerodynamic Drag Skin Friction Estimating Aerodynamic Coefficients Pitot Tubes Floating Real Time Operation Pressure Gradients Viscous Drag Thickness Hypersonic Speed Simulation Boundary Layer Thickness Control Theory Servomechanisms Forebodies Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
