|Thesis supervisor : ||
INSA Lyon - CETHIL (UMR 5008 INSA/CNRS/UCBL) Groupe Transferts Convectifs
The Low Temperature Laboratory (SBT) from CEA/INAC is involved in technological cryogenic research in a large temperature range from 120 K down to few tens of millikelvins. CETHIL (CNRS, INSA, UCBL) has a strong expertise in numerical simulation for systems involving flow study coupled to thermal transfer.
In SBT, the LCCS team (Cryocoolers and space cryogenics lab) develops small cryocoolers ranging from 50 mK up to 50 K. Among those developments, the pulse tube is a key component in the team. Based on the Stirling thermodynamic cycle, it allows to reach temperature between 4 K and 100 K with helium. They are used in satellite for earth observation (MTG, Met-Image) around 50 K. For space observation mission (ATHENA/X-IFU), a system able to reach 15 K has been developed and a prototype demonstrates an ultimate temperature of 4 K.
In CETHIL, the involved team has a strong expertise in numerical simulation of thermal transfer in fluid media. They are using CFD simulation and have developed their own numerical simulation dedicated to thermal studies. The team is also using massive parallel computation.
Based on the expertise of the 2 laboratories, the aim of the internship is to develop a model of a pulse tube that allows to cover the temperature range of 100 K – 4 K. A better comprehension of the phenomena inside the pulse tube is expected. Hence, a faster improvement of the performances. A combination of thermal modelling and oscillating flow dynamics for real gas is needed. The tool shall also be able to size multi-stage systems (Dual stage pulse tube, 15 K PT …). The model will be compared to experimental results already available in SBT but also on dedicated test bench to validate some sub-system of a pulse tube cooler. The test bench shall be developed during the PhD.
The PhD thesis will be both in Lyon at CETHIL laboratory for numerical simulation and in Grenoble at SBT for the experimental time.
The candidate shall have a master degree in the field of the thermal study, mechanic or energetic. He shall have background in thermodynamics, thermal transfer and simulation with an interest for thermal machines and physics.