Accession Number:

ADA002453

Title:

Induced Field-Point Pressures of a Ducted Propeller System.

Descriptive Note:

Final rept.,

Corporate Author:

NAVAL SHIP RESEARCH AND DEVELOPMENT CENTER BETHESDA MD

Personal Author(s):

Report Date:

1974-10-01

Pagination or Media Count:

44.0

Abstract:

Total fluctuating pressures were measured on the internal surface of a 0-degree angle-of-attack duct of a ducted propeller system Kort nozzle type. The effects of blade loading in uniform flow and propeller blade cavitation in nonuniform flow on the harmonics of the blade-frequency propeller-induced pressure were determined. Also determined were the blade-frequency pressure-induced duct forces. Experimental results indicate that the blade-frequency pressures increase for an increase in blade loading with the second and third blade-frequency pressure being significant with respect to the blade-frequency pressure. Fluctuating blade-frequency vertical forces determined by integrating the pressure results from nonuniform inflow noncavitating conditions were approximately 1-percent of the mean thrust. In the experiments conducted at a given loading, cavitation on the propeller blades tended to increase the blade-frequency pressure downstream of the propeller by as much as a factor of three.

Subject Categories:

  • Marine Engineering
  • Fluid Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE