Revisiting the Argus pulsejet engine of V-1 buzz bombs: An experimental investigation of the first mass-produced pressure gain combustion device

Abstract

Recent years have witnessed heightened focus on the operability and feasibility of various pressure gain combustion devices due to their attractive promise of increased thermodynamic efficiency. One such widely-researched pressure gain combustor is the pulsejet. The current paper details an experimental investigation performed on the most well-known pulsejet: the Argus As 014 pulsejet engines that were used to power the infamous V-1 “buzz” bombs during World War II. Incidentally, these engines also appear to be the most mass produced pressure gain combustors to date – more than 10,000 were launched at targets and many more manufactured. The engine tested here contains the actual outer casing made during the war, while the inner motor containing the shutter valves, air and fuel injection assemblies are dimensionally- and functionally-matching replicas made more recently. The exhaust plume behavior, far-field acoustic signature, skin and exit gas temperature, timing from valve opening to ignition and exhaust are gathered. The formation number of the ejected starting vortex is seen to be 2.5 and 3 for the conditions tested. The acoustic signature exhibits a peculiar directivity not seen in other unsteady devices, while producing up to 128 dB. The engine attains thermal steady-state within 15 s. However, the highest temperature is measured at the exhaust after a considerable distance of more than one meter. Finally, using the timing information and the other variables, it is noted that the Argus engine appears to behave like a Helmholtz resonator and not a quarter-wave as previously contended.