A Technique to Estimate the Transient Coefficient of Heat Transfer by Convection

Abstract

In this work we study the characteristics of the dissipation by convection of a solid circular section of a diameter d in a fluid. We assume that this section increases its temperature homogeneously over its whole surface from an initial temperature 𝒕𝒂 to the (asymptotic) temperature value 𝒕𝒎𝒂𝒙. To simulate its temperature behavior, we model the transfer of heat by conduction in an isolated one-dimensional bar of length L, where a constant temperature source F is considered at the left end, while keeping free the right end causing heat dissipation by convection. We propose a novel approach to estimate the heat transfer coefficient in the transient state. Numerical experiments are carry out for different materials. In order to measure the performance in the estimation, we conduct elasticity analysis. Also a comparison with data used in the literature is included.

Determination of Thermal Conductivities in Multilayer Materials

“…Example 1. A Nickel-Lead-Iron material is assumed where L = 10 m; F = 100 • C and T a = 25 • C. The convective fluid is assumed to be air and convective heat transfer coefficient (h) are determined as explained in [15]. It is also assumed that l 1 = 4 m and l 2 = 7 m.…”

Optimal Estimation of Thermal Diffusivity in an Energy Transfer Problem

“…for u ∈ C 2 (0, L) × C 1 (0, +∞) where κ [W/m • C] is the thermal conductivity coefficient of the bar material and h [W/m 2 • C] [33] is the heat transfer coefficient.…”

“…See, as an example, [11], [38]. The parameters that are most frequently estimated, under different assumptions and with different techniques, are: thermal conductivity [21], [35], thermal diffusivity [8], [31], sources of heat generation [32], [34], [40] and the coefficient of heat transfer by convection [23], [33].…”