Dependence of Propeller Efficiency on Angle of Attack of Propeller Blade Page: 3 of 9
This report is part of the collection entitled: National Advisory Committee for Aeronautics Collection and was provided to Digital Library by the UNT Libraries Government Documents Department.
The following text was automatically extracted from the image on this page using optical character recognition software:
is the efficienoy due to the slip.
For the stationary test the formula is simplified to
Vpr / lyF
In the above formulas
g is asooeleration due to gravity,
y is weight of I ou.m. of air in kg.,
S is thrust measured in kg.,
F is propeller disk in sq.m.,
VF is flight speed with reference to the air.
In order to be independent of the propeller slip, the total
effiolenoy is divided by the slip effiaiolenoy, and thus the me-
ohanical effioiency of the propeller is determined with relation
to angle of attack. (See B6rck, "Zeitschrift fur Sohiffbau,"
1919, Vol. XX, pp. 161 and 199.)
For the practical propellers unde= consideration, there
would have been no object in carrying the analysis of engine
ne experimental results rest on:
i. Eerinents b the writer at the "Flugzeugmeisterei"
(Technioal'Section of the Air Service);
2. Experiments performed by Dr. Schaffran with air pro-
peller models.in.the water at the institute for
hydrodynamios and ship building rider orders of
the inspector of the air forces.
3. Experiments with an "Eta" propeller on the propelled
testing stand at Fisohamend near Vienna, the re-
sults of which were played at my disposal by the
Eta propeller factory.
Here’s what’s next.
This report can be searched. Note: Results may vary based on the legibility of text within the document.
Tools / Downloads
Get a copy of this page or view the extracted text.
Citing and Sharing
Basic information for referencing this web page. We also provide extended guidance on usage rights, references, copying or embedding.
Reference the current page of this Report.
Borck, Hermann. Dependence of Propeller Efficiency on Angle of Attack of Propeller Blade, report, December 1921; (digital.library.unt.edu/ark:/67531/metadc53653/m1/3/: accessed November 18, 2018), University of North Texas Libraries, Digital Library, digital.library.unt.edu; crediting UNT Libraries Government Documents Department.