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Transonic airfoil design for helicopter rotor applications
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Hassan, Ahmed A. Jackson, B. |
| Copyright Year | 1989 |
| Description | Despite the fact that the flow over a rotor blade is strongly influenced by locally three-dimensional and unsteady effects, practical experience has always demonstrated that substantial improvements in the aerodynamic performance can be gained by improving the steady two-dimensional charateristics of the airfoil(s) employed. The two phenomena known to have great impact on the overall rotor performance are: (1) retreating blade stall with the associated large pressure drag, and (2) compressibility effects on the advancing blade leading to shock formation and the associated wave drag and boundary-layer separation losses. It was concluded that: optimization routines are a powerful tool for finding solutions to multiple design point problems; the optimization process must be guided by the judicious choice of geometric and aerodynamic constraints; optimization routines should be appropriately coupled to viscous, not inviscid, transonic flow solvers; hybrid design procedures in conjunction with optimization routines represent the most efficient approach for rotor airfroil design; unsteady effects resulting in the delay of lift and moment stall should be modeled using simple empirical relations; and inflight optimization of aerodynamic loads (e.g., use of variable rate blowing, flaps, etc.) can satisfy any number of requirements at design and off-design conditions. |
| File Size | 440814 |
| Page Count | 13 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19890015783 |
| Archival Resource Key | ark:/13960/t8rc1z90m |
| Language | English |
| Publisher Date | 1989-04-01 |
| Access Restriction | Open |
| Subject Keyword | Aircraft Design, Testing And Performance Transonic Flow Helicopters Iteration Aircraft Design Aerodynamic Characteristics Stalling Computer Aided Design Optimization Rotary Wings Aerodynamic Loads Computer Programs Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
