FITTING MODELS TO DETERMINE EXTERNAL PRESSURE COEFFICIENTS USING HARMONIC REGRESSION

Abstract

ABSTRACT Mathematical models to determine external pressure coefficients (Cpe) in conical silo roofs are scarce in silo design standards and scientific papers. These coefficients are dimensionless and are influenced by Reynolds number, air viscosity, geometry, and surface roughness of the material used in the structure. Pressure coefficients in conical roofs vary in the circumferential and meridional directions. Cpe values are essential in designing these structures to determine the pressures that arise from wind action. However, the scarcity of mathematical models for calculating external pressure coefficients in conical silo roofs made us conduct harmonic regression analyses to fit mathematical models based on experimental data developed in wind tunnels. Model fitting to experimental data had coefficients of variation lower than 10% in 87.5% (7/8) of the analyzed levels. These models are recommended for cases where wind gust duration does not exceed 3 seconds.

Keywords

• external pressure coefficients
• wind action
• conical roofs
• silos