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Toward comparing experiment and theory for corroborative research on hingeless rotor stability in forward flight
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Gaonkar, G. |
| Copyright Year | 1987 |
| Description | For flap lag stability of isolated rotors, experimental and analytical investigations were conducted in hover and forward flight on the adequacy of a linear quasisteady aerodynamics theory with dynamic flow. Forward flight effects on lag regressing mode were emphasized. A soft inplane hingeless rotor with three blades was tested at advance ratios as high as 0.55 and at shaft angles as high as 20 deg. The 1.62 m model rotor was untrimmed with an essentially unrestricted tilt of the tip path plane. In combination with lag natural frequencies, collective pitch settings and flap lag coupling parameters, the data base comprises nearly 1200 test points (damping and frequency) in forward flight and 200 test points in hover. By computerized symbolic manipulation, a linear model was developed in substall to predict stability margins with mode identification. To help explain the correlation between theory and data it also predicted substall and stall regions of the rotor disk from equilibrium values. The correlation showed both the strengths and weaknesses of the theory in substall ((angle of attack) equal to or less than 12 deg). |
| File Size | 1948131 |
| Page Count | 61 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19870019129 |
| Archival Resource Key | ark:/13960/t72v7f82j |
| Language | English |
| Publisher Date | 1987-08-01 |
| Access Restriction | Open |
| Subject Keyword | Aircraft Stability And Control Damping Rotary Stability Aircraft Stability Rigid Rotors Lift Drag Ratio Quasi-steady States Rotor Body Interactions Hovering Stability Resonant Frequencies Wind Tunnel Tests Flaps Control Surfaces Mathematical Models Aerodynamic Stalling 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 |
