Banca de DEFESA: ICARO FIGUEIREDO VILASBOAS

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : ICARO FIGUEIREDO VILASBOAS
DATA : 18/06/2019
HORA: 08:00
LOCAL: Escola Politécnica
TÍTULO:

Determination of thermophysical properties of naval steel ASTM A131 Gr. EH36 by the inverse heat transfer method

PALAVRAS-CHAVES:

thermophysical properties, ASTM A131 Gr. EH36, cryogenic spill, thermal conductivity, volumetric heat capacity, simultaneous optimization, sensitivity analyses, AISI A304

PÁGINAS: 88
GRANDE ÁREA: Engenharias
ÁREA: Engenharia Mecânica
SUBÁREA: Mecânica dos Sólidos
ESPECIALIDADE: Análise de Tensões
RESUMO:

This work aims to determinate the thermophysical properties of the naval steel ASTM A131 Gr. EH36 at low temperatures in order to enhancing the numerical models of structures subjected to accidental loads caused by cryogenic spill. For this purpose, the method of application of different heat flux intensities, which allows the simultaneous determination of the thermal conductivity ( ) and volumetric heat capacity ( ). The experimental apparatus consists of a resistive heater controlled by a power supply that generates a constant heat flux at the sample top surface. The bottom surface was isolated by expanded polystyrene plates and a thermocouple attached at the sample by capacitive discharge welding performs the temperature measurement. To calculate the temperature profile at the sample bottom temperature was used the finite difference method with implicit formulation. The square difference between the measured and calculated temperature was used as objective function and minimized through the BFGS (Broyden-Fletcher-Goldfarb-Shanno) method. The sensitivity analyses based on the scaled sensitivity coefficient and the experimental residue permits to verify the simultaneous optimization feasibility and the parameter convergence to a real value. Based on this analysis two heat flux intensities were required: one of an increased intensity, which enhances the scaled sensitivity of thermal conductivity, and one of a less intensity, which regulates the scaled sensitivity of volumetric heat capacity. The stainless steel AISI A304 was used to verify the effectiveness of the method, through a comparison between the optimized and the reference thermal properties. Based on the results of this work it can be affirmed that the method is able to determinate the thermophysical properties simultaneously with low experimental error.

MEMBROS DA BANCA:
Presidente - 2196670 - ARMANDO SA RIBEIRO JUNIOR
Interno - 465.982.515-91 - GERALDO JOSÉ BELMONTE DOS SANTOS - LNCC
Externo à Instituição - VALTER ESTEVÃO BEAL - Senai