Cooling air accelerated to match velocity of falling object eliminates drag. 3 meter drop tower with suction fan and specific geometry causes air to accelerate downward at 1 g. Although cooling of molten material released from top is slow because surrounding air moves with it, drop remains nearly spherical.
Drop tower with no aerodynamic drag
NASA Tech Briefs ; 5 , 4
1981-04-01
Miscellaneous
No indication
English
Engineering Index Backfile | 1958
|NTIS | 1973
Aerodynamic Drag and Drag Reduction
AIAA | 2003
|Truck aerodynamic drag reduction
NTRS | 1982