TEMPERATURE FORECAST IN CONCRETE DAM BY HOLTWINTERS MODELS AND THE FINITE ELEMENT METHOD

Resumo

The article describes a method of forecasting the temperature fields of a concrete block from the Itaipu
Hydroelectric Dam located in a region with high thermal gradients, approximately 7 to 40°C. The method involves
the application of Holt-Winters exponential smoothing models and a heat conduction model that follows Fourier's
Law. Initially, the temperature series, from 2000 to 2016, of two surface-to-block thermometers were adjusted by
cubic splines, and, the monthly series, were used as input for Holt-Winters to produce temperature forecasts as
outputs for 2017. Monthly (interpolated) and 2017 (predicted) monthly temperatures were used as boundary
conditions for the transient thermal block model and it was solved by the Finite Element Method (FEM) in Python
language. The predicted temperature fields of the block for 2017 are thus obtained. The numerical results at a
specific point and interior of the structure were compared with the observed data of an internal thermometer
installed in the block through the MAPE error, and this was around 7%. The proposed method has an innovative
approach to the thermal analysis of structures, particularly in concrete dams, regarding thermal field prediction
and the first application of the Python language to this problem.