STARLight Thermal

1
STARLight Thermal

• Tahir Rashid
• STARLight Mechanical Engineer
• [phone]
• trashid_at_umich.edu

2
Thermal Requirements

• Thermal Requirements
• During 1.5 second integration period, thermal
  stability across one receiver module must be lt
  11mK
• Thermal stability across one AD module must be lt
  1 K
• Temperature can vary between adjacent modules
• Ambient temperatures -30?C to 40 ?C
• Thermal control system to use less than 100 W
  Aircraft Power
• Simple and cost-effective
• Setpoint Operational Conditions
• Y-Thermal Plate Setpoint Values -20?C to 30
  ?C
• Receiver Thermal Plate Setpoint Values 2?C
  higher than Y-Plate
• Tolerance Range of Setpoint ? 0.1 ?C
• Fluid Setpoint 1?C lower than Y-plate setpoint

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Thermal Model Development

• Objective
• Does this design meet requirements for thermal
  stability?
• How well does system meet control setpoint?
• Estimate of time constant (in-flight on-ground)

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Thermal Model Development

• Thermal Network

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Time Constants Stability

• Estimate of Time Constants Stability once
  setpoint is achieved.

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Time Constants Stability

• Defn - Amount of time to reach setpoint value
  depends on
• Is temperature within tolerance range of
  Setpoint ? 0.1 ?C
• Is stability per requirements when within the
  setpoint range ?

Unstable
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Time Constants Stability

• 1?C Temperature Change during Flight Conditions
  (0.02 W)
• For Receiver Plate - 5 minutes to reach setpoint
  20?C
• For Thermal Plate 17.5 minutes to reach
  setpoint 20?C

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Time Constants Stability
9
Time Constants Stability

• 10?C Temperature Change during Ground Conditions
  (0.2 W Required)
• For Receiver Plate - 10 minutes to reach setpoint
  -30?C
• For Thermal Plate - 34 minutes to reach setpoint
  -30?C

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Time Constants Stability
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Time Constants Stability

• Temperature Change during Ground Conditions (9 W)
• For Receiver Plate - 12 seconds to reach setpoint
  of -30?C
• For Thermal Plate - 36 seconds to reach setpoint
  of -30?C

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Time Constants Stability
13
Model Summary

• Thermal stability requirement is achievable
• Since sensor module is a sealed-system, no
  external power will be required during ground
  operation. Turning on electronics will heat the
  sensor module very rapidly
• Operational Note Turn cooling system on prior to
  turning on electronics

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Thermal Control System (Mechanical)

• (Dwg 086-0075 X2)

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Thermal Control System (Mechanical)
Plate Setpoint Temp
MaCom LNA(0.5W)Switch(0.288W)
LNA (0.5W) LNA (0.5W)
Miteq LNA (1.2W)
Fluid Temp (0.09 gpm)
Fluid Temp (0.18 gpm)
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Thermal Control System (Mechanical)
Plate Setpoint Temp
Delay Line (0.132W)
16-Bit A/D (0.08W)
DAC (1.12W)
Fluid Temp (0.09 gpm)
Op Amp (0.594W)
6-Bit A/D (4W)
Fluid Temp (0.18 gpm)
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Thermal Control System (Electrical)
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Thermal Control System (Electrical)

• Design meets criteria of Aircraft power lt 100W

19
Thermal Control System Summary

• Design consists of mostly off-the-shelf
  components (simple cost-effective)
• A reduction in flow by ½ across the electronic
  modules will not affect the required heat
  transfer
• Design meets criteria of Aircraft power
  consumption less than 100W

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Prototype Testing

• Perform a Refrigeration Unit Test
• Objectives
• Verify Manufacturers Power Ratings under various
  ambient conditions
• Estimate Heat that can be dissipated by the
  Refrigeration System under extreme ambient
  conditions(-30?C to40 ?C)
• Examine Effects of Antifreeze on Cold Evaporator
  Plates
•  

21
Prototype Testing
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Prototype Testing

• Perform 2-Channel Prototype Test by using
  simulated heat loads
• Objectives
• Provide valuable insight into integration of
  sensor assembly mechanical design, refrigeration
  unit, and remainder of thermal control components
• Determine thermal time constants.
• Verify thermal stability at various ambient
  conditions, including extremes.
• Verify thermal stability during sudden ambient
  changes (thermal shock)
• Determine power consumption at various ambients.

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Schedule (Efforts to CDR)

• Test refrigeration unit (10/26/01)
• NovaKool Refrigeration Unit (Arrived 09/26/01)
• Test Procedure (086-0085x1) complete (10/12/01)
• Status of Other Off-the-Shelf Components
• Circulation Pump (Arrived 09/21/01)
• Filter In stock (Delivery by 10/10/01)
• Fittings, Tubing,Check Valves, Quick
  Disconnects,etc In stock (Deliver by 10/12/01)
• Strip Heaters In stock (Deliver by 10/11/01)

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Schedule (Efforts to CDR)

• Manufacture 2-channel prototype hardware
• Long-lead item is Aluminum Y-thermal plate
  (11/09/01)
• Dwg 086-0078 completed and provided for quotes
• Reservoir
• Dwg to be complete by (10/12/01)
• Manufactured in-house (10/24/01)
• Test stand
• Dwg to be complete by (10/26/01)
• Manufactured in-house (11/05/01)

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Schedule (Efforts to CDR)

• Perform testing of prototype in thermal chamber
• Test Procedure Complete by 11/02/01
• Start test using simulated loads (11/12/01)
  Finish (12/07/01)
• Analyze test results (12/14/01)
• Update Thermal ICD (Doc 086-0017) (02/08/01)