Features of the Application of the Iqlab Program for Solving the Inverse Heat Conduction Problem for Chromium-Nickel Cylindrical Thermosondes

Abstract

The paper presents an experimental-computational study of the results of using the IQLab program to solve inverse heat conduction problem and restore the surface temperature of cylindrical thermosondes from heat-resistant chromium-nickel alloys while cooling them in liquid media. The purpose of this paper is to verify the correct operation of the IQLab program when restoring the surface temperature of thermosondes with 1-3 thermocouples. The IQLab program is also designed to solve one-dimensional nonlinear direct lines and inverse heat conduction problems with constant initial and boundary conditions specified as a function of time in a tabular form with a constant and variable time step. A finite-difference method is used to solve the heat equation. Experiments were carried out on samples D = 10-50 mm in liquids with different cooling capacities such as aqueous solutions of NaCl and Yukon-E polymer, rapeseed oil and I-20A mineral oil. For the calculation we used the readings of thermocouples installed at internal points of cylindrical thermosondes. The advantages of solving inverse heat conduction problems with the IQLab program include the possibility of restoring the surface temperature for cylindrical samples with a diameter of 10 mm to 50 mm with practical accuracy according to the indications of a single thermocouple located in the geometrical center of the thermosonde, which simplifies the manufacture of the probe. For larger dimensions with a diameter D ≥ 50 mm, it is necessary to install control intermediate thermocouples and perform additional tests. The solution of inverse heat conduction problems and restoration of the surface temperature of the sample makes it possible to calculate other important characteristics of the cooling process: the heat flux density and the heat transfer coefficient.

Oligomer-containing Aqueous Quench Media Based on Polyethylene Glycol Esters of Oleic Acid

“…in Solutions PEG 400 Monooleate Using the parameters of the cooling curves (Figures . 4 (a,b)) presented in Table 1, the dependences of heat fluxes q(Тs) (Figure 6) and the heat transfer coefficient α(Тs) (Figure 7) were calculated using the INC solution method [23]. In the pearlite transformation temperature range of 650-400°С, the q(Тs) values rapidly increase and reach a maximum in the bainitic transformation region of 500-300°С, while the peak values of q(Тs) max noticeably decrease at an oligomer concentration of 1%wt.…”

Impact Mechanism of Interfacial Polymer Film Formation in Aqueous Quenchants

“…Using the data of cooling curves (Figure 5), presented in Table 1, by the method of IHC solution [34], the dependence of the value of heat fluxes q (Ts) and the heat transfer coefficient α (Ts) on the surface temperature Ts and the concentration of PAG-35 in water was calculated. Figure 14 shows the heat fluxes of PAG-35 solutions in the concentration range from zero to 10%wt.…”

“…Na-CMC Solutions Figure 16 shows the results of calculations by the IHC method [34] of heat fluxes q (Тs) in Na-CMC solutions and distilled water. On curve 1, Figure 16, there is a noticeable peak at about 775°C, which corresponds to boiling of the shock water film [33].…”