Feb 062012

Previously, we featured an article here at RetroMechanix.com on a Cornell study for a long range ram jet bombardment missile dating from March 1946. During this period, the Air Force appears to have been especially interested in this type of weapon, as it also issued a contract for a similar study by the Applied Physics Laboratory at The Johns Hopkins University, which published its own report on the subject on August 19, 1946.

According the abstract of the report, the powered range of a family of ram-jet propelled vehicles was calculated in order to determine the effect of various propulsion parameters and schemes. Included in the study was a variation in the air-to-fuel ratio and in the flight Mach number, the use of a normal shock maintained on the rim of the intake duct for compression, the use of a turbo-driven mechanical compressor, the use of a Kantrowitz-Donaldson type diffuser, and the use of a tail-pipe nozzle expanding the exhaust gases to atmospheric pressure. Based upon refined assumptions and revised figures for warhead and instrumentation requirements, a new and more accurate calculation of the ranges of the missiles analyzed previously was made.

The read the document in depth, please click through the image gallery above. The report includes inboard profiles of four ram jet configurations tested by Johns Hopkins. All feature unusual reverse delta wings, a cruciform tail, and a nose intake. Externally, they differ by the taper of the nose section, which reflects the type of diffuser employed, if applicable. Johns Hopkins appears to have evaluated each of these configurations in three sizes – a 40 ft long missile weighing 11,000 lbs; a 60 ft long missile weighing 40,000 lbs; and an 80 ft long missile weighing 100,000 lbs. Thus, the intrepid modeler wishing to scratchbuild one of these strange vehicles actually has 12 options to choose from.

All images from NARA Archives II, College Park, MD, RG 18

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