Tandem Air Propellers

One of 4,120 reports in the series: NACA Technical Notes available on this site.

PDF Version Also Available for Download.

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 ... continued below

Creation Information

Lesley, E P February 1, 1939.

Context

This report is part of the collection entitled: National Advisory Committee for Aeronautics Collection and one other and was provided by UNT Libraries Government Documents Department to Digital Library, a digital repository hosted by the UNT Libraries. It has been viewed 26 times . More information about this report can be viewed below.

Who

People and organizations associated with either the creation of this report or its content.

Provided By

UNT Libraries Government Documents Department

Serving as both a federal and a state depository library, the UNT Libraries Government Documents Department maintains millions of items in a variety of formats. The department is a member of the FDLP Content Partnerships Program and an Affiliated Archive of the National Archives.

Contact Us

What

Descriptive information to help identify this report. Follow the links below to find similar items on the Digital Library.

Titles

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.

Language

Item Type

Identifier

Unique identifying numbers for this report in the Digital Library or other systems.

  • : 93R10814
  • URL: http://hdl.handle.net/2060/19930081524 External Link
  • Report No.: NACA-TN-689
  • Center for AeroSpace Information Number: 19930081524
  • Archival Resource Key: ark:/67531/metadc54549

Collections

This report is part of the following collections of related materials.

National Advisory Committee for Aeronautics Collection

The National Advisory Committee for Aeronautics (NACA) was a U.S. federal agency founded on March 3, 1915 to undertake, promote, and institutionalize aeronautical research. On October 1, 1958 the agency was dissolved, and its assets and personnel transferred to the newly created National Aeronautics and Space Administration (NASA).

Technical Report Archive and Image Library

This selection of materials from the Technical Report Archive and Image Library (TRAIL) includes hard-to-find reports published by various government agencies. The technical publications contain reports, images, and technical descriptions of research performed for U.S. government agencies. Topics range from mining, desalination, and radiation to broader physics, biology, and chemistry studies. Some reports include maps, foldouts, blueprints, and other oversize materials.

What responsibilities do I have when using this report?

When

Dates and time periods associated with this report.

Creation Date

  • February 1, 1939

Added to The UNT Digital Library

  • Nov. 14, 2011, 10:28 p.m.

Description Last Updated

  • Feb. 2, 2017, 1:08 p.m.

Usage Statistics

When was this report last used?

Yesterday: 0
Past 30 days: 0
Total Uses: 26

Interact With This Report

Here are some suggestions for what to do next.

Start Reading

PDF Version Also Available for Download.

Citations, Rights, Re-Use

Lesley, E P. Tandem Air Propellers, report, February 1, 1939; (digital.library.unt.edu/ark:/67531/metadc54549/: accessed August 19, 2017), University of North Texas Libraries, Digital Library, digital.library.unt.edu; crediting UNT Libraries Government Documents Department.