1941-01-01

VIBRATION CHARACTERISTICS of Three- and Four-Blade Propellers for HIGH-OUTPUT Engines 410142

ALTHOUGH the problems involved in developing a satisfactory engine-propeller airplane installation using propellers of four or more blades are admittedly more difficult than those encountered with a three-blade propeller, Mr. Guerke points out, a satisfactory installation can be made “if the airplane designer will assume the responsibility of reducing propeller interference effects.” This, of course, may be very difficult if not impossible to accomplish in “pusher” installations, he qualifies. Reporting that two such installations have been made in a normal tractor four-blade installation without recourse to odd blade spacing, he contends that successful installations also can be accomplished in propellers of five or more blades under similar conditions.
Dual-rotation propellers, he believes, will introduce additional propeller design problems of a vibration nature which may require certain compromises in diameter, blade construction, and engine gear ratios before satisfactory installations can be made. Mr. Guerke opines, however, that these compromises can be made without sacrificing airplane performance.
In the technical discussion that precedes the foregoing conclusions, Mr. Guerke takes up engine excitation; aerodynamic excitation; aerodynamically excited three-blade propeller vibration; aerodynamically excited four-blade propeller vibration; methods of reducing or avoiding aerodynamically excited stress; dual rotation; and effects of propeller isolation on aerodynamically excited stress.

SAE MOBILUS

Subscribers can view annotate, and download all of SAE's content. Learn More »

Access SAE MOBILUS »

Members save up to 16% off list price.
Login to see discount.
Special Offer: Download multiple Technical Papers each year? TechSelect is a cost-effective subscription option to select and download 12-100 full-text Technical Papers per year. Find more information here.
We also recommend:
TECHNICAL PAPER

THE EFFECT OF PROPLETS AND BI-BLADES ON THE PERFORMANCE AND NOISE OF PROPELLERS

810600

View Details

TECHNICAL PAPER

Development of Advanced Propeller Damper (Shift Dampener System)

2013-32-9068

View Details

TECHNICAL PAPER

Study on Reduction of Brake Squeal Caused by In-plane Vibration on Rotor

2001-01-3158

View Details

X