Papers by Leonid Dombrovsky
International Journal of Heat and Mass Transfer, 2007
thermal radiation heat transfer because he is considered a pioneer in radiation heat transfer. Hi... more thermal radiation heat transfer because he is considered a pioneer in radiation heat transfer. His research has centered on developing solution techniques for radiative transfer in participating media (particularly the Monte Carlo method), solutions of highly non-linear combined mode heat transfer problems, the catalog of the shape factors, the benchmark solutions of the radiation heat transfer problems, heat transfer in energy systems, and most recently, inverse design and control of thermal systems with combined-mode (non-linear) heat transfer.
Fuel, 2003
Absorption spectra of several types of diesel fuel are studied experimentally. Index of refractio... more Absorption spectra of several types of diesel fuel are studied experimentally. Index of refraction of these fuels is calculated using subtractive Kramers–Krönig analysis. The ageing process of fuels is simulated by prolonged boiling. Radiative properties of diesel fuel droplets are calculated using the Mie theory and a simplified approach, based on approximations of absorption and scattering efficiency factors. It is
Heat Transfer Engineering, 2003
A considerable temperature difference in semitransparent oxide particles due to intensive heating... more A considerable temperature difference in semitransparent oxide particles due to intensive heating in plasma spraying makes it difficult to interpret the optical measurements of their temperature. The problem of determining the bulk temperature of such particles from the experimental data on the color temperature is analyzed by using a recently proposed approximate model for the radiation transfer inside a nonisothermal refracting spherical particle. The same approximation is also employed for developing an improved model of particle heating, taking into account the radiation-conduction interaction inside the particle. Calculations for Al 2 O 3 and ZrO 2 particles in a typical plasma jet show that the color temperature of oxide particles may be less than or greater than their bulk temperature, depending on the spectral absorption coefficient of particle substance. This temperature difference during the melting of particles may reach the value of 200-300 K. A procedure for in situ evaluation of the absorption coefficient by comparison of color and brightness temperatures of molten particles is proposed.
Teplofizika Vysokikh Temperatur
ABSTRACT
Teplofizika Vysokikh Temperatur
Precipitation of particles from a laminar isothermal aerocolloidal flow is described, focusing on... more Precipitation of particles from a laminar isothermal aerocolloidal flow is described, focusing on the dependence of critical conditions on gas blowing from the surface of the wall. Critical Stokes numbers are calculated for the flow Reynolds numbers of 10 to the 2nd, 3rd, 4th, and 5th with consideration of the various blowing parameters on the basis of a numerical solution to the problem. It is concluded that the analytical solution yields values of the Stokes number that practically coincide with the exact results over the entire investigated range of blowing parameters.
Teplofizika Vysokikh Temperatur
Teplofizika Vysokikh Temperatur
A two-step approximate analytical solution for the normal emittance of a plane layer of an absorb... more A two-step approximate analytical solution for the normal emittance of a plane layer of an absorbing, scattering and refracting medium is derived analytically. The analysis is based on the transport approximation and the two-step solution method for radiative transfer. The high accuracy of the approximate solution, examined by comparing its results to those obtained independently by the discrete ordinates and Monte Carlo methods, makes it suitable for application in combined experimental-analytical studies to identify selected spectral radiative properties of dispersed media in the range of semi-transparency.
Teplofizika Vysokikh Temperatur
ABSTRACT
Teplofizika Vysokikh Temperatur
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Journal of Heat Transfer
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Journal of Engineering Physics and Thermophysics
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Thermal Engineering
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Thermal radiation of large semi-transparent spherical particles is modeled on the basis of differ... more Thermal radiation of large semi-transparent spherical particles is modeled on the basis of differential approximation suggested earlier by the author. This approach is employed to solve transient radiative-conductive problems for nonisothermal particles. Two applied problems for metal oxide particles are considered: the diagnostics of particle temperature in plasma spraying and solidification of core melt droplets during fuel-coolant interaction. It is shown that effect of particle semi-transparency in the near-infrared spectral range may be significant for both thermal radiation intensity and the physical picture of the particle solidification.
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Papers by Leonid Dombrovsky