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Performance optimization of helicopter rotor blades
| Content Provider | Semantic Scholar |
|---|---|
| Author | Walsh, Joanne L. |
| Copyright Year | 1991 |
| Abstract | As part of a center-wide activity at NASA Langley Research Center to develop multidisciplinary design procedures by accounting for discipline interactions, a performance design optimization procedure is developed. The procedure optimizes the aerodynamic performance of rotor blades by selecting the point of taper initiation, root chord, taper ratio, and maximum twist which minimize hover horsepower while not degrading forward flight performance. Satisfactory aerodynamic performance is defined by the following requirements which must hold for any flight condition: the required horsepower must be less than the available horsepower; the section drag divergence Mach number on the advancing side of the rotor disc must be avoided, the maximum section lift coefficient on the retreating side of the rotor disc must be avoided, the high nose down pitching moments on either side of the rotor disc must be avoided; and the rotor blade must be trimmed. The procedure uses HOVT (a strip theory momentum analysis) to compute the horsepower required for hover and the comprehensive helicopter analysis program CAMRAD to compute the horsepower required for forward flight and maneuver. The optimization algorithm consists of the general purpose optimization program CONMIN and approximate analyses. Sensitivity analyses consisting of derivatives of the objective function and constraints are carried out by forward finite differences. The procedure is applied to a test problem which is an analytical model of a wind tunnel model of a utility rotor blade. The hover analysis is performed using nonuniform inflow without a wake model. The forward flight analysis is performed with and without wake models. |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19910016823.pdf |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
