Thermal Tests Analysis of transient response Elena Daskalaki Alex Vamvakas Athanasios Zelios

Aim 2 To find the time constant of each component as a function of: Power applied Water flow Component geometry Ambient conditions

Theory ΔΤ τ % of ΔΤ

Tests plan P1 F1 T1 P2 F1 T1 P3 F1 T1 P1 F2 T1 P2 F2 T1 P3 F2 T1 P1 F3 T1 P2 F3 T1 P3 F3 T1 P1 F1 T2 P2 F1 T2 P3 F1 T2 P1 F2 T2 P2 F2 T2 P3 F2 T2 P1 F3 T2 P2 F3 T2 P3 F3 T2 P1 F1 T3 P2 F1 T3 P3 F1 T3 P1 F2 T3 P2 F2 T3 P3 F2 T3 P1 F3 T3 P2 F3 T3 P3 F3 T3 4

Time constants SAS T amb = 20 o CT amb = 30 o C 5

Time constants PETS T amb = 20 o CT amb = 30 o C 6

Theoretical analysis geometry water flow To copper To air To water 7

Theoretical analysis Comparison of SAS temperature profile: Experimental vs theoretical data 8

Conclusions 9 Time constant of SAS ranges between 4-11 minutes. Time constant of PETS ranges between minutes. In both cases, the time constant depends highly on water flow. The time constant does not depend on applied power and ambient temperature. Theoretical analysis matches very well with experimental data. This allows us to use this model for the prediction of the transient and steady-state response of the components. The time constant of the components can be controlled as desired through the regulation of the water flow.

Comments 10 The PETS cannot be heated independently of the DBQs DBQs are very slow compared to PETS and SAS (~ 3 hours to reach steady-state) PETS are strongly coupled to DBQs because of o Their proximity o The heating of the cooling channel which connects the two PETS units The conclusions reached from the analysis of PETS cannot be as accurate as those of the SAS.

Next steps Repetition of representative cases with both temperature and alignment measurement Improvement of DB heating system for more accurate analysis How accurate do we want to be? Analysis of failure modes 11