...
Flutter - Yasu
Thermal (Eric + Juan)
Omega's 5 Points:
HOW TO CHOOSE A THERMOCOUPLE
1. Determine the application where the thermocouple will be used
2. Analyze the temperature ranges the thermocouple will be exposed to
- Max 800 K (980 F) --> Type J, E suit this max (J: 32 - 1400 F, E: -328 - 1600)
3. Consider any chemical resistance needed for the thermocouple or sheath material
4. Evaluate the need of abrasion and vibration resistance
5. List any installation requirements
- Coltronic 4700 thermal epoxy
Sheath Considerations (for sheated thermocouples)
- Grounded vs Ungrounded --> We want grounded (probe wires are physically attached to the wall of the sheath) to maximize thermal contact, no concern for electrical isolation
Other Notes:
https://www.epj-conferences.org/articles/epjconf/pdf/2017/12/epjconf_efm2017_02075.pdf
Calibration is key
Temperature Calibration Uncertainty detailed in Guide to exp. Of Uncertainty in Measurement
“Intrinsic Thermocouples” might give us better spatial resolution (microtips)
https://www.epj-conferences.org/articles/epjconf/pdf/2017/12/epjconf_efm2017_02075.pdf
Seebeck effect
G,C,D are for high temp, K for VERY high temp
NiCr-NiAl used in experiment is oxidation proof, resistant to higher temps, reducing atmosphere, and sulphur compounds
“The thermocouple-based method has some limitations. One of the major problems is attaching a thermocouple to the surface to be measured. Incorrect bonding may cause the device to show a temperature lower than the actual one. When a thermocouple is used to measure the temperature of an element in a high frequency radio circuit, it may change the electrical characteristics of that circuit. A thermocouple fixed to a small electronic element may be responsible for the removal of heat from the element. As a result, the temperature displayed is lower than the actual temperature, i.e. one measured before the thermocouple was attached. Decalibration may lead to an error in measurement; it may change the electrical characteristics, which will make the reading inaccurate. Finally, an open thermocouple junction may also cause errors in temperature measurement [19]. "
Possibly add IR Thermal camera for data fusion
...
Vibration (Yasu)
ceramic piezoelectric sensor/ accelerometer
single axis / triaxial accelerometer
Engineer’s guide to accurate sensor measurements: http://download.ni.com/evaluation/daq/25188_Sensor_WhitePaper_IA.pdf
what’s the effect of the constant acceleration/deceleration of the rocket on the sensors?
triaxial, +-500g, 2~7000Hz model(356B21): $1,125
...