Ken Wright Sensis Corporation January 28, 2010 Modeling and Simulation Challenges and the New Vehicle NRA
2 Background Analyze the combined impacts of advanced vehicles and NextGen
3 Vehicles M 0.78, 35k – 40k ft 2000 nm M k ft to 53k ft 4000 nm 1200 nm M 0.5, 25k ft CESTOL SST LCTR UAS 750 nm 400 nm VLJ M 0.28, 15k ft M 0.6, 35k ft
4 Background (Continued) Timeframe –2025 –2040 (roughly 2 times today’s traffic levels) –3X (3 times today’s traffic levels) Tasks –Design vehicles –Develop usage scenarios –Compute delay –Compute environmental impacts –Compute metroplex impacts –Compute safety impacts –And much more
5 Model Infrastructure
6 The Focus of this Presentation is ACES To do NAS-wide simulation in ACES we need: BADA Data Schedules/Capacities ACES tracks used by AEDT to compute environmental impact
7 General Modeling Simulation Observations Designing good experiments is tough –Results often seem obvious –Difficult to translate concepts into hypotheses that leverage model strengths Difficult to spot erroneous results –Large datasets, complex interactive models –Figuring what’s going on below the surface is difficult Some modules don’t work well with large datasets –Results not significantly impacted –New features can increase run time, without affecting results –ACES 5.0 vs ACES 6.2 compatibility issues
Challenge: Demand Generation
9 JPDO-Provided Demand Sets
Huge delays at LAS and ATL due to capacity-demand imbalance dominate systemwide-results
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13 ACES-Specific Observations MPAS (physics model) currently can’t fly unconventional vehicles –Cruise-Efficient STOL Aircraft (cruises too slow) –Supersonic transport (cruises too fast) –Tiltrotor (takes off like a helicopter) Tail-tracking Terminal area tracks Conflict Detection and Resolution Weather obstacles (Back-up)
14 Tail-Tracking One-third of all delay is propagated delay ACES tail-tracking doesn’t quite work
15 Sensis Itinerary-Creation Algorithm gives 5-6 Stages per Airframe
16 Increase in delay due to tail-tracking too small to be realistic
Aircraft is in two places at the same time
18 Short flights show discontinuous tracks Flights having great circle distance less than about 60 nm fly discontinuous “X” routes Affects 3,000 to 3,500 ACES flights in 2040 dataset (about 3.5% of total) Because flights fly longer routes than necessary, amount of time spent airborne is too long.
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22 Flight from TEB to LGA is Airborne for 31 Minutes. Average speed = 21 mph
23 Conflict Detection and Resolution Not used in New Vehicle project Causes about as many conflicts as it resolves
CDR Causes Collision
26 CDR Causes Collision
Aircraft sense impending 5-nm conflict CDR Causes Collision
Aircraft move to avoid 5-nm conflict CDR Causes Collision
Aircraft move to avoid 5-nm conflict CDR Causes Collision
Boom! CDR Causes Collision
57 3X-Dataset No restrictions on international arrivals leads to large sectors exceeding capacity limits
2086
Foreign arrivals choke off domestic departures. (175k flights)
60 Conclusions Big project; tested lots of models; pushed limits of ACES and AEDT It’s probably more fun to be a developer than a user Coming up with interesting experiments is tough –Experiments should leverage model strengths to find novel results Difficult to spot erroneous results Some modules/capabilities did not work as expected for our large- scale experimental configuration
Ken Wright Sensis Corporation Questions?
Back up
63 Rerouting around Weather Mostly worked, but number of weather polygons scenario could use was unnecessarily limited Peculiar reroutes due to lack of airborne holding capability in ACES
64 Clusters of Storm Cells (>=50 DBZ) Replaced by Rectangles Clusters of Storm Cells (>=50 DBZ) Replaced by Rectangles
65 Clusters of Storm Cells (>=50 DBZ) Replaced by Rectangles Clusters of Storm Cells (>=50 DBZ) Replaced by Rectangles
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80 Final fix blocked
81 Final fix blocked
82 Final fix blocked
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92 It appears that the flight turns around only when it bounces off another weather cell
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