Advanced Technology Solar Telescope ENCLOSURE

1. Advanced TechnologySolar Telescope ENCLOSURE

2. Overview & Charge to Committee (Mark Warner) 6 Major Parts of SDR: SRD Flow Down & Error Budgets (Rob Hubbard) Specifications (LeEllen Phelps) Reference Designs (LeEllen) Lunch Performance & Analyses (LeEllen) Contracting Approach (Mark) Risk Areas (LeEllen) Plans for Future Work (LeEllen) AOB Executive Session (closed session for committee members) Feedback from Committee (All Hands) -------------------------------------------------------------------------------------------------------- Dinner Explain I�ll get back to the 5 parts in a moment We have a couple of short breaks scheduled throughout the day, plus a lunch at noonExplain I�ll get back to the 5 parts in a moment We have a couple of short breaks scheduled throughout the day, plus a lunch at noon

3. Function: Suppress seeing Outline here: What are we talking about? Thermal Performance I Gemini tests MuSES modeling Validation using Gemini data Hybrid Retractable Is this good enough? Seeing Performance Formulation: thermally disturbed layers Chart, in terms of average temperature of upstream skin BBSO tests to verify/sanity check Thermal Performance II Hardware modifications, hybrid Hardware modifications, retractable MuSES results w/mods Summarize Outline here: What are we talking about? Thermal Performance I Gemini tests MuSES modeling Validation using Gemini data Hybrid Retractable Is this good enough? Seeing Performance Formulation: thermally disturbed layers Chart, in terms of average temperature of upstream skin BBSO tests to verify/sanity check Thermal Performance II Hardware modifications, hybrid Hardware modifications, retractable MuSES results w/mods Summarize

5. Overview: Requirements and Goals Configuration for analyses CFD Results Phases 2, 3 at Fluent Inc. (Phase 1 was an old design) Validation via CosmosFloWorks

6. Requirements and Goals Minimum of 20 enclosure volumes per hour �passive� air flushing For wind speeds greater than 2 m/s from any azimuth direction No stagnant �dead zones� inside enclosure Ability to �throttle� down interior air flow as outside wind speed increases (max interior air velocity = 5 m/s) No direct sunlight to enter enclosure System should fully seal out weather during non-operational periods (e.g., overnight, rainy periods) Low-risk, high-reliability system COTS-type equipment Equipment easily serviced, replaced

8. CFD Results: Fluent, Phase 2 Three wind directions : East, South, and South East One wind speed: 5 m/s (11.2 MPH) Shutter angle: 45-degrees elevation Results meet requirements and goals: ~36-240 enclosure volumes/hour (requirement: 20) Minimal flow up side of enclosure Minimal recirculation inside enclosure Mostly single-pass recirculation Good air flow through dome centerline (i.e., telescope location) 30-40% of outside wind speed from floor to ceiling

9. Velocity Vectors

10. CFD Results: Fluent, Phase 3 Additional Runs North flow cases (with rear vent/access door) Shutter angle effects (15 deg from horizon, zenith) E, S, N, SE flow cases Telescope obstruction effect One wind speed: 5 m/s (11.2 MPH) Results consistent with Phase 2 results: ~35-220 enclosure volumes/hour (requirement: 20) Flow mostly �thru� flow, with some single-pass recirculation TMA causes a minor flow disruption Primarily at base of TMA, below mirror Some slowing of flow downstream of TMA Minor reduction (~3-5%) of total throughput through enclosure Good flow/flushing across optical path of TMA

12. Velocity Contours with TMA

16. CFD Results: Validation

17. Overview: MuSES for performance analyses for design development Other tools for Lower Enclosure for optimization Results M3 designs �Value Engineering�

18. MuSES Modeling: Validation at Gemini North

22. Dark, volcanic, rocky background�Dark, volcanic, rocky background�

23. Dark, volcanic, rocky background�Dark, volcanic, rocky background�