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Tandem air propellers
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Copyright Year | 1939 |
| Description | Tests of 2-blade, adjustable-pitch, counter rotating tandem model propellers, adjusted to absorb equal power at maximum efficiency, were made at Stanford University. The characteristics, for 15 degrees, 25 degrees, 35 degrees, and 45 degrees pitch settings at 0.75 R of the forward propeller and for 8-1/2 percent, 15 percent, and 30 percent diameter spacings, were compared with those of 2-blade and 4-blade propellers of the same blade form. The tests showed that the efficiency of the tandem propellers was from 0.5 percent to 4 percent greater than that of a 4-blade propeller and, at the high blade-angle settings, not appreciably inferior to that of a 2-blade propeller. It was found that the rear tandem propeller should be set at a blade angle slightly less than that of the forward propeller to realize the condition of equal power at maximum efficiency. Under this condition the total power absorbed by the tandem propellers was from 3 percent to 9 percent more than that absorbed by the 4-blade propeller and about twice that absorbed by a 2-blade propeller. |
| File Size | 15189416 |
| Page Count | 28 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19930081524 |
| Archival Resource Key | ark:/13960/t5v72mx90 |
| Language | English |
| Publisher Date | 1939-01-01 |
| Access Restriction | Open |
| Subject Keyword | 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 |
