ABSTRACT
Centrifuge modelling has been considered as an effective means for investigating the energy and geotechnical performance of thermo-active geo-structures. A major challenge to correctly model (i) soil-structure heat transfer and (ii) thermo-mechanical behaviour of the geo-structure in a centrifuge is to design a system that could deliver sufficient heat energy (i.e. in terms of flowrate and temperature) under enhanced gravity conditions. This paper reports a new and robust heating/cooling system developed for these purposes and evaluates its performance. The proof heating tests performed up to 50-g suggest that when an appropriate pipe configuration is designed, the heating system is capable of producing a water flowrate up to 13.5 ml/s, which is sufficient to generate a turbulent flow regime within the water circulation pipe, hence maximising the convective heat transfer mechanism. The heating system has been successfully applied to deliver a controllable amount of heat energy, simultaneously, to multiple thermo-active piles in a row for warming up the surrounding soil. With proper thermal insulation of the pipework of the system, temperature loss between the target value at the pipe inlet and the one registered at the entrance of the model structure could be less than 2°C. An idea for extending the system to lower the temperature below ambient is also presented.
