Determination of graphite sublimation rate in high enthalpy plasma flow using ‘laser knife’ method
| Autor: | Valery F. Chinnov, Makhach Kh. Gadzhiev, Mikael A. Sargsyan, Dmitry I. Kavyrshin, Aleksey G. Ageev |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Fluid Flow and Transfer Processes
Argon Materials science Mechanical Engineering chemistry.chemical_element Laminar flow 02 engineering and technology Plasma 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences 010305 fluids & plasmas Anode chemistry 0103 physical sciences Thermal Sublimation (phase transition) Graphite Composite material 0210 nano-technology Plasmatron |
| Zdroj: | International Journal of Heat and Mass Transfer. 107:146-153 |
| ISSN: | 0017-9310 |
| DOI: | 10.1016/j.ijheatmasstransfer.2016.11.023 |
| Popis: | The experimental method to study a behavior of heat-resistant materials by the action of high-enthalpy plasma jets is developed. The main attention is focused on heating and thermal destruction of graphite samples. The argon plasma jet is generated by a plasmatron with an expanding anode channel providing a slightly divergent high-enthalpy laminar flow with the axial speed of 400–500 m/s, the diameter of 6–8 mm and high temperature which is not less than 10,000 K. The jet affects the isotropic graphite MPG-6 samples shaped in the form of a parallelepiped with the dimensions of 23 mm × 23 mm × 16 mm. A description of the method developed by the authors on the basis of the “laser knife” technique to determine the sublimation rate of heat-resistant materials is presented and the relevant time change in the sample material sublimation rate is analyzed. The shape and evolution of craters on the sample surface are analyzed. A nonmonotonic behavior in the sublimation is observed in the experiments. The maximum of sublimation rate is recorded when the initial warming up stage of the graphite sample is completed, which indicates the emergence and propagation of dislocations in graphite structure as it is heated to a temperature close to 3000 K. |
| Databáze: | OpenAIRE |
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