Accession Number : AD0452792


Title :   EFFECTS OF AIRFRAME GEOMETRY ON DOWNWASH PROBLEMS OF TANDEM DUCTED- PROPELLER VTOL AIRCRAFT


Descriptive Note : Rept. for Jul 61-May 63,


Corporate Author : KELLETT AIRCRAFT CORP PHILADELPHIA PA


Personal Author(s) : Pruyn, Richard R


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/452792.pdf


Report Date : Jan 1964


Pagination or Media Count : 134


Abstract : A full scale half-model simulation of a dual tandem ducted propeller VTOL aircraft has been tested at heights of less than two duct diameters above sand and water terrane. Data on terrain transport, terrain caused aircraft damage, flow field measurements and ducted propeller performance were obtained. These tests were conducted at propeller disc loadings up to 60 pounds per square foot with various aircraft configurations and ducted propeller orientations. The dual tandem configuration was found to cause a significant increase in downwash problems compared to isolated propeller configurations previously tested. Reduced performance, severe engine and propeller damage and an oscillating aerodynamic interference were experienced. Several promising devices to alleviate downwash problems were evaluated.


Descriptors :   *VERTICAL TAKEOFF AIRCRAFT , DEFLECTION , MODEL TESTS , DUCTS , INTERFERENCE , DUCTED FANS , DOWNWASH , DUCT INLETS , GROUND EFFECT , PERFORMANCE(ENGINEERING) , FLUID DYNAMICS


Subject Categories : V/STOL


Distribution Statement : APPROVED FOR PUBLIC RELEASE