Neutron phase volumetry and temperature observations in an oscillating heat pipe

► An experimental study on an oscillating heat pipe was performed using neutron imaging. ► The liquid volume fraction in components of the OHP was determined. ► From the volume fraction data, fluid dynamics of water of the OHP were investigated. ► The liquid is predominantly distributed in the condenser while heat is input. ► There is synchronization between the liquid oscillation and temperature oscillation.