9,020 research outputs found
Simulation test results for lift/cruise fan research and technology aircraft
A flight simulation program was conducted on the flight simulator for advanced aircraft (FSAA). The flight simulation was a part of a contracted effort to provide a lift/cruise fan V/STOL aircraft mathematical model for flight simulation. The simulated aircraft is a configuration of the Lift/Cruise Fan V/STOL research technology aircraft (RTA). The aircraft was powered by three gas generators driving three fans. One lift fan was installed in the nose of the aircraft, and two lift/cruise fans at the wing root. The thrust of these fans was modulated to provide pitch and roll control, and vectored to provide yaw, side force control, and longitudinal translation. Two versions of the RTA were defined. One was powered by the GE J97/LF460 propulsion system which was gas-coupled for power transfer between fans for control. The other version was powered by DDA XT701 gas generators driving 62 inch variable pitch fans. The flight control system in both versions of the RTA was the same
A Tunable Echelle Imager
We describe and evaluate a new instrument design called a Tunable Echelle
Imager (TEI). In this instrument, the output from an imaging Fabry-Perot
interferometer is cross-dispersed by a grism in one direction and dispersed by
an echelle grating in the perpendicular direction. This forms a mosaic of
different narrow-band images of the same field on a detector. It offers a
distinct wavelength multiplex advantage over a traditional imaging Fabry-Perot
device.
Potential applications of the TEI include spectrophotometric imaging and
OH-suppressed imaging by rejection.Comment: 11 pages, 12 figures, accepted by PAS
Mathematical model for lift/cruise fan V/STOL aircraft simulator programming data
Simulation data are reported for the purpose of programming the flight simulator for advanced aircraft for tests of the lift/cruise fan V/STOL Research Technology Aircraft. These simulation tests are to provide insight into problem areas which are encountered in operational use of the aircraft. A mathematical model is defined in sufficient detail to represent all the necessary pertinent aircraft and system characteristics. The model includes the capability to simulate two basic versions of an aircraft propulsion system: (1) the gas coupled configuration which uses insulated air ducts to transmit power between gas generators and fans in the form of high energy engine exhaust and (2) the mechanically coupled power system which uses shafts, clutches, and gearboxes for power transmittal. Both configurations are modeled such that the simulation can include vertical as well as rolling takeoff and landing, hover, powered lift flight, aerodynamic flight, and the transition between powered lift and aerodynamic flight
Astrophotonic micro-spectrographs in the era of ELTs
The next generation of Extremely Large Telescopes (ELT), with diameters up to
39 meters, will start opera- tion in the next decade and promises new
challenges in the development of instruments. The growing field of
astrophotonics (the use of photonic technologies in astronomy) can partly solve
this problem by allowing mass production of fully integrated and robust
instruments combining various optical functions, with the potential to reduce
the size, complexity and cost of instruments. In this paper, we focus on
developments in integrated micro-spectrographs and their potential for ELTs. We
take an inventory of the identified technologies currently in development, and
compare the performance of the different concepts. We show that in the current
context of single-mode instruments, integrated spectrographs making use of,
e.g., a photonic lantern can be a solution to reach the desired performance.
However, in the longer term, there is a clear need to develop multimode devices
to improve overall the throughput and sensitivity, while decreasing the
instrument complexity.Comment: 9 pages. 2 figures. Proceeding of SPIE 9147 "Ground-based and
Airborne Instrumentation for Astronomy V
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Insight into the evolution of the Tagish Lake carbonaceous chondrite by analysis of the oxygen isotopic composition of extracted water and Mössbauer spectroscopy
Analysis of oxygen isotopes in water from Tagish Lake together with Mössbauer Spectroscopy suggest some similarities to the CI group of meteorites but also suggest differences in the extent of parent body hydrothermal alteration
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