Title:
Modeling Convection Boundary Conditions for Ultra-High- Performance Concrete in Cylindrical Columns
Author(s):
Ashley S. Carey, Isaac L. Howard, Alta Knizley, and Jay Shannon
Publication:
Materials Journal
Volume:
117
Issue:
3
Appears on pages(s):
123-131
Keywords:
boundary condition; numerical modeling; temperature prediction; ultra-high-performance concrete
DOI:
10.14359/51724595
Date:
5/1/2020
Abstract:
In this paper, a numerical model for radial-direction conduction through ultra-high-performance concrete (UHPC) cylinders was developed and experimentally validated. The focus of this research is ultimately to improve understanding of UHPC’s thermal behavior, with this portion focused on determining a convection heat-transfer coefficient for appropriate boundary condition modeling. Although constant heat-transfer coefficients are commonly assumed in literature, this paper shows that many commonly assumed constant coefficients overestimate convection performance for natural convection boundary condition environments. For well-studied geometries, numerical solutions including a temperature and time-dependent convection coefficient produced errors under 1%, whereas constant heat-transfer coefficient assumptions produced errors up to 10%. However, for less-common geometries, numerical model errors ranged from 2 to 5%.