Transport Coefficients of Ag–SiO2 Plasmas

Abstract

International audienceCalculated values of viscosity, thermal and electrical conductivities of plasma formed in mixtures of silver (Ag) and silica (SiO2) are presented. The calculations, which assume local thermodynamic equilibrium, are performed for three pressures (1, 10 and 30 atm) in the temperature range from 4,000 to 30,000 K. All the data for the potential interactions and the necessary formulations to obtain values of transport coefficients are given in details. For atmospheric pressure, five mixtures (100% Ag, 75% Ag and 25% SiO2, 50% Ag and 50% SiO2, 25% Ag and 75% SiO2, 100% SiO2) in weight percentage are studied. In order to analyse the pressure influence on the transport coefficients, three samples of Ag–SiO2 mixtures (100% Ag, 50% Ag and 50% SiO2, 100% SiO2) in weight percentage are discussed for pressures of 1, 10 and 30 atm. In addition for the test case of oxygen plasma, we compare the computation code results with values obtained by other authors: discrepancies are found and explained

Thermodynamic Properties and Transport Coefficients of Nitrogen, Hydrogen and Helium Plasma Mixed with Silver Vapor

“…The specific heats are shown in Fig. 4(b), similar tendencies are shown in the curves with two partial peaks of which the peak at 7, 000 K is formed because of ionizations of atomic silver and molecular nitrogen whereas the peak at 15,000 K is generated because of the ionization of atomic nitrogen [20] . There is only one peak on the specific heat of the silver plasma and the other peak at 15,000 K disappears since no nitrogen atom exists.…”

“…[10] H2-H Interpolation of data from Ref. [30] He-He L-J [20,29] , ε/kB=10.22 K, σ=0.256 nm Ag-Ag L-J [20,29] , ε/kB=8,000 K, σ=0.222 nm Others L-J potential with parameters in Table 3 , and Ag + in the plasmas. Therefore, there should be in total 31 interactions in these plasmas taking the symmetry of the interactions into consideration, and their data source and calculation methods are all listed in Table 4.…”

Basic knowledge on radiative and transport properties to begin in thermal plasmas modelling

“…Then, the next papers have been focused on specific applications such as low voltage circuit breakers with or without metallic vapors, 73,78-83 medium voltage circuit breakers, 84 the high voltage circuit breakers, [85][86][87] powders synthesis, 88,89 the atmospheric reentry, [90][91][92][93][94][95] or the recent applications focused on the production of nanostrucutres, 96 syngas, 97 optimisation of the lamps, 98,99 pollutants detections. 100,101 By using the Chapman-Enskog method 102 firstly adapted for monoatomic and neutral gases and then extended to ionized gases, the transport coefficients are approximated using Sonine polynomials and require the knowledge of the particle number densities and other functions called "collision integrals" which strongly vary according to the temperature, according to the potential of interaction used to characterize the collision between the particles, and according to the order of approximation chosen for the Sonine development.…”

Wpływ oparów metalicznych na spawanie łukowe, część 2: Obliczanie

“…Jest to częściowo spowodowane tym, że nie są one w centrum zainteresowania, a częściowo z powodu braku dokładnych danych całek zderzeniowych w przypadku oddziaływania pomiędzy drobinami metalu oraz pomiędzy drobinami metalu a innymi cząstkami. Najbardziej skomplikowane potencjały międzyatomowe, które zostały zastosowane w obliczeniach plazmy, opracowano dla mieszaniny argonu z miedzią [97] oraz mieszaniny srebra z dwutlenkiem krzemu [98]. W pracach tych do obliczenia całek zderzeniowych w przypadku oddziaływania pomiędzy neutralnymi drobinami metalu zastosowano potencjał Hulburta-Hirschfeldera [99÷101].…”

“…Przegląd sPawalnictwa 7/2012 w obliczeniach plazmy, opracowano dla mieszaniny argonu z miedzią [97] oraz mieszaniny srebra z dwutlenkiem krzemu [98]. W pracach tych do obliczenia całek zderzeniowych w przypadku oddziaływania pomiędzy neutralnymi drobinami metalu zastosowano potencjał Hulburta-Hirschfeldera [99÷101].…”