Thermal Design-General Properties Heated by Kapton isolated heating foils Optimized for the use with limited area and weight standards Optimized for vacuum conditions Operating range: -32°C to 150°C Resistance tolerance: ±10% or ±0.5 Current limit: 3.0A at 100°C (AWG 30) Minimum bending radius: 0.8 mm Deliverable from stock ( Meltingprobe Midterm Meeting:
Thermal Design-Electrical Properties Temperature dependent resistance: RT Resistance temperature coefficient: TCR = / /°C Supply voltage: 28V Maximum power density: 4 W/cm² Operation temperature limited to 60°C Temperature controlled by sensors type Pt100 (7.6 mm x 7.6 mm, operating range –200°C to 200°C) Meltingprobe Midterm Meeting:
Thermal Design-Dimensional Requirements I Type 1: x=50.8, y=50.8 mm, placed at the inner envelope walls Type 6: x=19.8, y=70.1 mm, placed at the inner walls of the tip Type 11: x=34.3, y=11.4 mm, placed at the bottom of the tip Meltingprobe Midterm Meeting:
Thermal Design-Dimensional Requirements I Meltingprobe Midterm Meeting:
Thermal Design-Foil Positioning F1 heat segment Q1 F2+F3 heat segment Q2 F4ǁF5ǁF6 heat segment Q3 F7ǁF8ǁF9 heat segment Q4 F10ǁF11ǁF12 heat segment Q3 Meltingprobe Midterm Meeting: Heating equipment segmented in 5 regions:
Thermal Model I Differentiated into subdomains: , , c, Q S1...brass tip S2...heating element Q1 S3...heating element Q2 S4...heating element Q3 S5...heating element Q4 S6...heating element Q5 S7...envelope of the MP S8...top cap of the envelope Meltingprobe Midterm Meeting:
Thermal Model II Meltingprobe Midterm Meeting: With: Q = 0 without heating foils Q = P/V [W/m³] with heating foils depending on the parameters of the foils used Equation of heat transfer:
Thermal Model III Parts of the surface of the probe not covered with ice; the surface of the ice All other boundaries, thermal insulation Meltingprobe Midterm Meeting: Boundary conditions:
Thermal Model-Different Scenarios Meltingprobe Midterm Meeting: )The MP is surrounded by vacuum, only Q1 and Q2 are active 2)The MP has penetrated the ice to a depth of 1.5 mm, Q1 and Q2 active 3)The MP is surrounded by ice, all Q´s have been deactivated and the probe has cooled down. After a certain time the Q´s are reactivated
Thermal Model–Results Case 1 Meltingprobe Midterm Meeting:
Thermal Model–Results Case 2 Meltingprobe Midterm Meeting:
Thermal Model–Results Case 3 Meltingprobe Midterm Meeting: L1 L2
Thermal Model–Results Case 3 Meltingprobe Midterm Meeting: Temperature at L1: z=0.1, r= 0.1 Temperature at L2: z=0.201, r= 0.1
Thermal Model–Outlook Including the influence of the self heating of the tether Including the influence of the electronics box Combine this model with a model calculating the sinking of a cylinder Meltingprobe Midterm Meeting:
Thermal Model–Outlook Meltingprobe Midterm Meeting: