A feasibility studyfortheapproval of liquid metalseedsrecovery froma liquid metalvapor-inert gasmixture was conducted and presented in this report. The research activity included background studies on processes relating tomixingstream condenser performance, parametric studies and its experimental validation.The condensation processunder studyincludesmass transfer phenomena combined withheattransfer and phasechange. Numerical methodswereusedinorder tosolve thedynamicequations and tocarry out the parametric study as well as the experimental data reduction. The MSC performance is highly effected by droplet diameter, thus the possibility of atomizing liquid metals were experimentally investigated.The results are generalized and finally used for a set of recommendations by which the recovery of seeds is expected to be feasible.

Vortex reconnection is explored in order to understand coherent structure evolution and interactions, as well as its role in fundamental turbulence phenomena such as cascade and mixing. Due to lack of measurement techniques for such topology-changing events, particularly for capturing the instantaneous 3D velocity and vorticity fields, we rely on well-resolved direct numerical simulations of the Navier-Stokes equations. The reconnection process is found to consist of a set of generic stages including bridging, threading and head-tail formation. Reconnection is incomplete as the self-induced motions of bridges and threads suggest a physical mechanism of cascade to smaller scales via successive bridging and threading: the number of stages increases with Reynolds number. These observations lead us to suggest that reconnection processes play an important role in cascade, entrainment and mixing in turbulent flows.

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