Experimental Investigation of Singular Two-phase Pressure Losses Relevant to Nuclear System Thermal-hydraulic Applications

A fully funded 4-year EPSRC ICASE PhD Studentship, co-sponsored by Westinghouse, is available in the Nuclear Futures Institute at Bangor University to design and perform experiments at the THOR loop to measure two-phase pressure drop across selected simple geometrical singularities within a relevant range of conditions.

The project is in collaboration with Westinghouse Electric Sweden AB and the University of Sheffield (c/o Prof. Shuisheng He). In addition, the project will benefit from the support from international experts as part of the FONESYS (Forum & Network of System Thermal-Hydraulics Codes in Nuclear Reactor Thermal-Hydraulics) and SILENCE (SIgnificant Light and Heavy Water Reactor Thermal Hydraulic Experiments Network for the Consistent Exploitation of the Data) networks.

In nuclear reactors, singular pressure losses are fundamental to the overall behaviour of the reactor coolant under both normal and accident conditions. For most design basis accidents, the predicted reactor transients by thermal-hydraulic system codes can be significantly impacted by pressure losses, affecting the overall dynamic behaviour of the system and associated safety margin to design criteria. Under two-phase natural circulation conditions upon which safety system of advanced reactor relies, singular pressure losses can significantly affect the coolant flow rate and hence the long-term heat removal capabilities of the reactor. Singular pressure losses are relatively well known under single-phase conditions. However, under two-phase flow condition (typical of reactor transients and two-phase natural circulation) large uncertainties are expected due to the lack of fundamental understanding of the irreversible form losses across singularities.

In the proposed project, this knowledge gap will be addressed based on a specific test program at the THOR facility at Bangor University. Examples of geometries that will be investigated include an orifice with varying inner diameter and length in an expanding and contracting manner, and/or geometries with obstacles, either in a vertical or horizontal orientation.

The student stipend is £19,237 per annum in the first year, with all fees and other costs covered. Generous funding is also available for training, conference and workshop attendance.

The successful candidates are expected to hold a first class or upper second-class degree in engineering, physics or applied mathematics. Interests in experimental thermal-hydraulics, CFD, and nuclear engineering are desirable but pre-knowledge and experience are not essential. The student is expected to present their research outcomes to the project team/sponsors on a regular basis in both written and oral formats. Proficient in English (speaking and writing; Bangor University requires an IELTS score of 6.5. https://www.bangor.ac.uk/international/future/englishlanguage) (essential).

This project is co-sponsored by Westinghouse Electric Sweden AB.

For further information, please contact Dr Walter Villanueva w.villanueva@bangor.ac.uk

To apply, please send your CV and relevant credentials (e.g., IELTS, transcripts, degree certificates) to Dr Walter Villanueva w.villanueva@bangor.ac.uk.