HALO Inlets
Inlet Systems for HALO
Currently enviscope is involved in the design, construction and certification of various inlet systems for the new German research aircraft HALO. Some of the intakes are designed for gas phase measurements, some are designed with respect to an optimized aerosol flow to the instruments.
The standard Trace Gas Inlet (TGI) is under development on behalf of German Aerospace Center Flight Facility Oberpaffenhofen (DLR-FF). This intake will be part of the basic equiment provided by the DLR-FF for scientific users working with in-situ equipment aboard the HALO aircraft.
The design of the intake allows different tubing configurations to be integrated into the inlet structure, thus providing a high flexibility to the scientific user community. To achieve this, the tubing and ducting system is built in a modular way enabling an individual sampling equipment – according to the respective demands – to be integrated by simply exchanging the complete tubing assembly. Therefore it is possible for the scientific users to prepare and to bring their own tubing assembly and mount it to the inlet during the preparation phase of an experiment.
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General mounting options:
- The inlet can be mounted on each of the prepared aperture plates;
- Two different heights are available: The smaller one is intended to be operated in the forward positions, the longer version for rearward mounting positions of the aircraft;
- The inlet can be mounted with one forward directed sampling tube and 3 backward directed tubes or vice versa;
- Each of the tubes can have a diameter up to ½ inch, e.g. 1/2″ or 3/8″ or 1/4″. Any combinations of those diameters are possible;
- The material of the tubes can be chosen according to the requirements, e.g. stainless steel, PTFE or PFA;
- Different feed-throughs are possible. The pressure flange can be exchanged with the assembly;
- Special configurations are possible as long as the assembly fits to the body.
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Click on above picture to open an animation showing the stepwise disassembly of the intake to mount different tubing configurations.
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Two HALO-TGI inlets (long and short version)
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The same design principles as for the TGI have been used for the intake DUALER designed on behalf of University of Bremen. This inlet hosts a reaction chamber inside the pylon housing for the measurement of highly reactive gas species.
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Aerosol measurements will be possible on HALO with the Counterflow Virtual Impactor Inlet (CVI) (on behalf of IfT Leipzig) as well as with the HALO Aerosol Standard Inlet (HASI) (on behalf of IPA/DLR), which are as well challenging design tasks.
The aerosol particles have to be sampled isoaxial to the intake tube and afterwards being deccelerated in the counterflow or diffusor arrangements. To achieve this, a shroud assembly has been attached to parallelize the flow around the sample inlet tip.
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A third aerosol intake, the so-called Micrometer Aerosol Inlet (MAI), is currently being developed for IfT Leipzig as a passive flow nested diffsor type inlet.
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Beside these in-situ probing intakes, optical inlets are under development as well: Stabilized Platform for Airborne solar Radiation Measurements (SPARM) is an inlet hosting a radiation sensor that is actively horizontalized by a two axis platform (already installed on the HIAPER aircraft in the USA).
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Last but not least the Hygrometer for Atmospheric Investigations (HAI) (on behalf of the University of Heidelberg/Research Centre Juelich) represents an open path inlet for water vapor measurements. The laser light beam is folded by mirrows between the two pylons to achieve an optical path length of 4.8 m.