Notes from IEEE:

- change in temperature less than 2K across tank [nearly isothermic] 

-24 hour turnover rate of fluid from cryogenic pump

• Sensors:
  • Static 
  • Floating around 

Would a moving sensor affect the thermodynamics/temperature of the liquid?

Look into: 

• https://www.realpars.com/blog/thermocouple Thermocoupling 
• What homogeneous temperature are we trying to achieve? [so that we know what temperature the sensors have to withstand]
• Is cost an important factor to the sensor?
• What is the goal of the sensor suites across the multiple tests? 
  • Is it measuring temperature for all of them 
• Optimal Placements
  • Within physical mixing device (minimize the # of extra sensors within the tank]
• Understand what each test is doing c

Tests our sensor setups have to perform in:

• Cryocooler Performance Test
• Baffle & Pump Cryogenic Flow Test 
• Thermal Subsystem Demo 
• Mixing Subsystem Demo 

Thermal Subsystem Demo: 

Testing whether a cryogenic tank wrapped in insulation and cooled by a cryocooler can keep its liquid from boiling away in a space-like vacuum environment.

How-to-test:

• Boil-off flow: mass-flow meter on vent line (gas phase)

• Mass loss: weigh the filled tank before/after

• Level sensor (capacitance/RTD stack) to track liquid height over time

• Temperatures: many thermocouples on tank wall, loop inlet/outlet, MLI outer surface, heater panels

Mixing Subsystem Demo - Testing that the pump can mix cold fluids with induced heat stratification in low gravity environments. Flight test on parabolic arc with 20 second periods of microgravity, or ground test by spinning the tank to create and artificial gravity and then stopping the tank suddenly.

• Sensors: thermocouples(mixing of fluid), pressure sensor(LN_2 boils off easily), liquid level sensor(detect sloshing and boil off), flow meter(how much fluid is being moved), IMU/accelerometer(identify periods of microgravity), voltage sensor(how much heat is added for induced stratification)