Paraffin-based expansion actuators form the basis of a new, sustainable class of actuators that can be used as robust, adaptive actuators for the targeted application of high forces (up to 100 kN). The solid-liquid phase transition leads to an increase in the volume of the paraffin, while the resulting internal pressure in the closed actuator housing leads to a positioning force. Heat from the environment, e.g. process waste heat, can be used to activate the actuators. The material properties of paraffins change significantly in the phase transition. Knowledge of the temperature-dependent thermal conductivity of the paraffin is necessary for the exact numerical mapping of the actuator behaviour. For the characterisation of heat transfer coefficients and thermal conductivities of solids, a test rig is available at the PtU, which is to be used in this work to determine temperature-dependent thermal conductivity coefficients for paraffins. For the measurement of the liquid phase, the test rig concept must be extended and adapted. Depending on interest, the focus can be on experimental, constructive or numerical aspects. This can be agreed in a personal discussion.

Research method

Experimental, numerical, analytical, constructive