The Estimation of Time-Varying Thermal Contact Conductance Between Two Fixed Contacting Surfaces

Abstract

Nomenclature c pspecific heat, J/kgK; e RMSroot mean square error, K; h cthermal contact conductance, W/m 2 K; H-Hilbert space of square-integrable functions; Imaximum number of parameters; kthermal conductivity, W/mK; Llength, m; Nnumber of sensors; qheat flux, W/m 2 ; Sobjective function, K 2 ; ttime, s; t ffinal time, s; Ttemperature, K; T 0-constant temperatures at specimens' end, K; T iinitial temperature, K; Ymeasured temperatures, K; x-Cartesian spatial coordinate. Greek symbols αthermal diffusivity, m 2 /s; δdistance from the interface, m; Δdistance between two sensors, m; ΔTtemperature drop, K; ρdensity, kg/m 3. Subscripts ii-th parameter; jj-th sensor; kk-th sensor.

A Backward Reciprocity Function Approach to the Estimation of Spatial and Transient Thermal Contact Conductance in Double-Layered Materials Using Non-Intrusive Measurements

“…The same authors mentioned that values of thermal contact resistance presented in the literature differed significantly, probably due to the fact that they were derived from different experimental conditions. Shojaeefard et al [9,10] time-dependent thermal contact conductance using the conjugate gradient method with adjoint problem, but again using intrusive measurements. Gill et al [11] solved an inverse heat conduction problem to estimate the spatial distribution of thermal contact resistance.…”

Study of the periodic thermal contact between exhaust valve and its seat in an internal combustion engine

“…Using analytical laboratory work, Popov et al [32] were able to determine the contact heat transfer between two surfaces in periodic contact. Most experimental installations of thermal contact between the seat and the exhaust valve of an internal combustion engine [16,[34][35][36]39] consist of two unidimensional bars with their ends maintained at a constant temperature. The bar tower is insulated; radiative heat transfer is neglected, so only one-dimensional heat transfer will be studied.…”