Unsteady RANS Calculations of Perturbed Natural Circulating Flow Within an Experimental Test Loop

 By Deacon Marshall, Sophie L Brown, Ryan Tunstall, Alex Skillen

Published in Nuclear Future 21.3

DOI: https://doi.org/10.63198/CSQY3991

SUMMARY

• The implications of transient events can have significant influence on the cooling capabilities of a natural circulation loop, where perturbations such as cold fluid injection can hinder natural circulation flow.
• Comparisons have been made between unsteady Reynoldsaveraged Navier-Stokes (RANS) computations to highfidelity Large Eddy Simulation (LES) results for a simple natural circulation loop.
• Two transient types were considered; low point cold fluid injection for 2000 seconds, and zero power scenarios where the heat input was removed once a steady state was established.
• The results from RANS and LES were shown to be comparable in their predictions of bulk mass flow rate and temperature trends, with both transient types demonstrating a reduction in prevailing mass flow rate and heat transfer capability.

LEAD AUTHOR

Deacon Marshall holds the position of Thermofluid Engineer at Rolls-Royce plc, his focus being in developing computationally feasible analysis methods to substantiate fluid system safety. He has a BEng (Hons) in Aerospace Engineering from Sheffield Hallam University with a thesis on CFD analysis .