AWG 2011 – CVI Update K Turnbull, P Barrett

Table of Contents Organics Infrastructrure Upgrades CVI Replacement Lyman Alpha Hygrometer Baseline Size dependant collection effeciency (large particles >25micron) COSIC

Organics Tip cleaned Furnace heated in 02 deficient atmosphere to prevent combustion 2-cycles at up to 700°C Desorbtion of materials Followed by ultrasonic bath to remove and residual particles Testing problems at Icing Tunnel and on Aircraft – Autumn 2010 – AMS fuses Ongoing – awaiting tests, Aircraft or Icing tunnel

CVI Replacement Limited options – depends on driver from results of organics tests Rought draft of document circulated, but effort put on hold, awaiting funding news Using the Brechtel Iso-kinetic inlet (MOCCA aircraft) may stimulate interest in aquiring a Brechtel CVI for BAe146? No money? None at Met Office! If organics are present – see following table:

New control software needed to collect data from external instruments Money Time 1. Brechtel Pros: Purpose built, other groups use same Minimal design work for CVI CFD is underway on inlet $$$$$ 80K + Recert. costs &&& Redesign full rack, New control software needed to collect data from external instruments Cons: price Time – redesign of rack recert. Costs, new hole in aircraft skin 2. Modify Current CVI tip We can redesign tip for new science reqs. Lower cut size Sample larger particles Better heating / deicing Keep same inlet arm Cheaper $$ Exeter Uni Engineering support – fairly cheap, but may need prototypes for mods &&&& Redesign tip, including testing, verification of transmission efficiency Needs to build and test prototypes? same pumping/drying system, same (lossy) plenum distribution need to design, draw and build (outsource) manufacture of new tip no CFD to check tip design Need to prove inlet works in order to publish Waste of money if tip fails 3. Make direct copy of current tip Cheap easiest option remove (possible) organics contam. $ Exeter Uni Engineering support – fairly cheap Cost~4k – for alu tip w/ heaters, etc & Design time (Solidworks) needed Cut size is too high tip is blunt very hard to heat/de-ice the tip inlet is narrow – low efficiency for large (ice) particles

Lyman Alpha Hygrometer Lab work to determine baseline drift due to electronics – detector+amps humidity exposure density Data Analysis to fit “out of cloud” baseline drift due to Sample Air Density (due to O2 absoprtion of ly-A) cumulative moisture exposure (“Fogging” of Mg2F windows due to H2O and λ(uv)) Ongoing – but progress made

Size Dependant Collection Efficiency – Large Particles Comparison vs. Nevzorov, low IWC during CONSTRAIN – B496 m=~0.5 m=~0.8 Nevz. vs. CVI. For Left: MVD < 75µm Right: MVD > 150µm Nevz. vs CVI. IWC with MVD filtering

COSIC work Ongoing – data to be reprocessed – watch this space Work on CONSTRAIN hygrometer will inform on re-procseeing requirements May be possible to recover the data for B516, B517

The Future CVI will fly during COALESCE – AMS testing? PCASP has been upgraded to SPP-200 electronics, with the same laser, and optics block as previous. Flight testing during COALESCE Any funding for upgrades? Next projects for CVI/AMS?

Extra slides

Attack Angle Efficiency B496 CVI vs Nevz as Fn(AoA) B496 CVI vs Nevz as Fn(Pitch)

Altitude Dependance Not much Nevz. Goes –ve in places due to imperfect baseline CVI does the same but has set to zero here, where -ve

Lyman-A baseline fit