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 terrarn. 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. (Author)
Effects of Airframe Geometry on Downwash Problems of Tandem Ducted-Propeller VTOL Aircraft
1964
127 pages
Report
No indication
English
Downwash Impingement Design Criteria for VTOL Aircraft
NTIS | 1964
|Ducted Propulsion Units for VTOL Aircraft
NTIS | 1968
|Ducted fan in VTOL aircraft design
Engineering Index Backfile | 1959
|Engineering Index Backfile | 1959