Determination of the True Temperature of Molybdenum and Luminous Flames from Generalized Wien’s Displacement and Stefan–Boltzmann’s Laws: Thermodynamics of Thermal Radiation

Abstract

The true temperature of thermal radiation of molybdenum and luminous flames is defined from the temperature dependences of generalized Wien's displacement and Stefan-Boltzmann's laws. For determining the true temperature of molybdenum, experimental values of either the position of the maximum of the spectral emitted density or the total emitted density are needed. It is shown that the thermal radiation of molybdenum belongs to the same universality class as that of tantalum, tungsten, and zirconium and titanium carbides. The thermodynamic functions of thermal radiation of molybdenum and luminous flames are constructed.

Radiative Properties of Stoichiometric Hafnium, Titanium, and Zirconium Carbides: Thermodynamics of Thermal Radiation

“…In [17,18], it was shown that in the case of a blackbody, Eq. 1 differs negligibly from the Wien displacement law [21].…”

“…7, at the melting temperatures [23], we obtain the following values for the position of the maximum of the spectral energy density: In conclusion, it is important to note that a similar law of the relationship (Eq. 7) between the true temperature T and the position of the maximum ν max of the normal spectral energy density was obtained for tantalum, tungsten, and molybdenum [16][17][18]. This means that the emitted radiations of molybdenum, tantalum, tungsten, and stoichiometric zirconium, titanium, and hafnium carbides belong to the same universality class.…”

“…In [17], by using the generalized Stefan-Boltzmann law, thermodynamics of the thermal radiation of molybdenum and luminous flames had been constructed. The temperature dependences of the free energy, entropy, heat capacity, pressure, and total energy at high temperatures were obtained.…”

“…In [16][17][18][19][20], an optical non-contact method for determining the true temperature of bodies has been proposed. A principal idea was to use experimental data of the normal spectral emissivity as a function of temperature to construct the generalized Wien displacement and Stefan-Boltzmann laws.…”

“…This study focuses on further development of a non-contact optical method for determining the true temperature as well as for the construction of the thermodynamic functions of the thermal radiation of bodies that was previously proposed in [16][17][18][19][20]. In the framework of the examples, the generalized Wien displacement and Stefan-Boltzmann laws are investigated for stoichiometric hafnium, titanium, and zirconium carbides.…”