Description:
OBJECTIVE: To develop accurate nonintrusive techniques to track sub-missile dispense in very high speed flows. DESCRIPTION: Missile carriage has been both proposed and used as a practical means for the delivery and dispense of sub-missiles while offering the advantage of quick response out to a considerable range. Here the term sub-missile covers a broad spectrum to include munitions, airframes, ISR (Intelligence, Surveillance, and Reconnaissance) platforms, supplies, flechettes, and even warhead fragments. Such sub-missiles may themselves be powered, unpowered, guided, unguided, intelligent, or passive devices. Regardless of the type, clean dispense from the carrier missile remains a key problem area for the designer with sub-missile-to-missile, and sub-missile-to-sub-missile interactions to be resolved. Often the dispense technique for a particular design can only be validated through flight testing which is problematic enough and especially so at endoatmospheric conditions and flight Mach numbers from the supersonic into the hypersonic range. Recently, the Army has developed a shock tunnel based ground test facility that permits free flight stage separation and sub-missile dispense. The facility is unique in that it can produce the flow conditions required to duplicate flight conditions of interest to missile developers (fully duplicated flight conditions) with all the advantages provided by a ground test facility for accurate test measurements. Principally because of the extremely short facility run times (typically 10 to 100 milliseconds) the types of instruments commonly used are limited primarily to pressure, heat transfer rates, and accelerometer measurements. What is needed then for sub-missile dispense ground testing is an accurate nonintrusive technique to track a finite number of dispense objects in three-dimensions. The number of objects to track could be simply one for an ISR platform to as many as one hundred for flechettes. The existing nonintrusive laser methodologies for flowfield velocity measurements, LDV (laser doppler velocimetry) and PIV (particle image velocimetry), might possibly be adapted for this particular application since flowfield seeding is not an issue. Starring array CCD cameras and tomographic techniques offer another possibility. Still, issues with the short run times and flowfield line-of-sight access must be addressed. PHASE I: This solicitation seeks innovative ways to make nonintrusive three-dimensional measurements (position and velocity) of sub-missiles during free flight dispense in a ground test facility at flight Mach numbers from 2 to 12 and altitudes from sea level to 80 km. Positional accuracies to +/- 2.5 mm over a spherical envelope of 2.5 m diameter are desired. Technical approaches will be formulated for new and innovative ways to make these measurements. These approaches shall be distilled into a measurement concept(s). Phase I will then produce one or more preliminary designs for innovative measurement devices. PHASE II: The concepts formulated in Phase I will be developed and refined in order to design and build an instrument. The instrument shall be demonstrated in an aero-propulsion facility defined by the Government. A test program demonstrating the capability of the instrument will be formulated and the instrument tested in this facility. Test measurements shall be validated by comparison with known experimental results or well characterized analytical results. PHASE III: If successful, the end result of this Phase-I/Phase-II research effort will be a validated aero-propulsion measurement instrument. The transition of this product will require additional tests to insure the validity, accuracy, and range of the measurements. Furthermore, practical limits to the number of dispense objects which can be tracked will need to be developed. For military applications, this technology is directly applicable for validation testing of all systems utilizing missile delivery and sub-missile dispense to include stage separation and shroud separation, wherein multi-body interactions must be characterized utilizing the tracking instrument and technology of this SBIR. For commercial applications this measurement technology as an instrument has direct use for tracking particulates in a gas stream, e.g. coal particulates in a cyclone furnace. The most likely customer and source of Government funding for Phase-III will be those service project offices responsible for the development of missile delivered sub-missiles to include munitions, airframes, ISR (Intelligence, Surveillance, and Reconnaissance) platforms, supplies, and fragmenting warheads.
