Accession Number:

ADA067742

Title:

The Characteristics of the Spray Generated by the Efflux of Various Aircraft Propulsors Impinging Normally on Water.

Descriptive Note:

Rept. for May-Sep 78,

Corporate Author:

DAVID W TAYLOR NAVAL SHIP RESEARCH AND DEVELOPMENT CENTER BETHESDA MD AVIATION AND SURFACE EFFECTS DEPT

Personal Author(s):

• Papadales, Basil S., Jr

Report Date:

1978-06-01

Pagination or Media Count:

52.0

Abstract:

A review of previous model tests of the efflux from aircraft propulsors impinging normally on water is presented. The height of the resulting spray cloud was found to be a function of the maximum dynamic pressure at the surface after impingement, and the propulsor diameter. A generalized relationship using these variables, based on Froude scaling and which favorably compares with the existing model data is presented. Other characteristics of the water surface and spray cloud are discussed, although there are insufficient data to formulate any general conclusions. Results from tests with Froude-scaled vertical takeoff and landing aircraft models are presented. These results are tentative due to the lack of substantiating full-scale data. The height of a spray cloud and the water depression diameter obtained during Froude-scaled tests of a conceptual ducted fan propulsor are also presented. The spray cloud heights compares favorably with the generalized relationship derived from previous tests. The water depression diameter was found to differ substantially from that determined from previous model tests. Spray cloud heights and water depression diameters are predicted for two conceptual full-scale aircraft propulsors. Author

Descriptors:

• *VERTICAL TAKEOFF AIRCRAFT
• *JET STREAMS
• *SEAPLANES
• *VERTICAL LANDINGS
• SCALE MODELS
• NAVAL AIRCRAFT
• SEA WATER
• DYNAMIC PRESSURE
• SMALL SHIPS
• IMPINGEMENT
• DUCTED FANS
• SPRAY NOZZLES

Subject Categories:

• VSTOL
• Fluid Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE