The calculation results were validated with experimental data. The effects of diminishing rod-rod gap size on local flow, heat transfer and coherent structure in tight lattice were analyzed.

Any given volume of water contains two types of molecular structures-one a blobby, loosely packed agglomeration and the other a tight, regular arrangement resembling a crystal lattice.

This paper preliminarily analyzed the advantage of a reactor core with rod type element in tight triangle lattice, and briefly introduced its application in small and medium nuclear power plants.