Thermophoretic deposition near the leading edge of cylindrical surfaces

Georgiou, D. P.; Kladas, D. D.

doi:10.1016/0017-9310(91)90198-n

Cited by 4 publications

(2 citation statements)

References 7 publications

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“…Solid particles are transfered to the blade surfaces by inertia, eddy diffusion, Brownian motion and thermophoresis. Previous work (1,4,5,6,7,8) has shown that smaller particles (d < 0.01 pm) are transported to the blades mainly by Brownian diffusion, larger particles (0.01 -1 pm) by eddy diffusion and thermophoresis, while supermicron particles are guided by inertial forces, resulting in blade erosion. Smaller particles which stick on the blade surface through adherence forces form a sticky layer on which larger particles agglomerate.…”

Section: -Gt-345mentioning

confidence: 97%

Turbine Cascade Optimization Against Particle Deposition

Kladas

Georgiou

1992

Volume 3: Coal, Biomass and Alternative Fuels; Combustion and Fuels; Oil and Gas Applications; Cycle Innovations

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Modern turbine cascades are usually being optimized for minimum total pressure losses. Gas turbines, however, operating in dirty environments or using coal–derived fuels need cascades that minimize the deposition, erosion and corrosion (DEC) implications of the particle–laden gas. This can be achieved by altering certain geometrical key–parameters of cascades and blades which influence the particle deposition rate, while keeping the inlet and outlet velocities and angles fixed. Since reference cascades have already been optimized for minimum aerodynamic losses, the associated loss increase penalty is accounted for. Two stator and two rotor cascades were optimized by a penalty function method. The results suggest that solid particle deposition rates can be minimized by as much as 40 per cent while keeping profile losses to acceptable limits in both stator and rotor cascades for the particle size range 0.1 to 1 μm.

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Section: -Gt-345mentioning

confidence: 97%

Turbine Cascade Optimization Against Particle Deposition

Kladas

Georgiou

1992

Volume 3: Coal, Biomass and Alternative Fuels; Combustion and Fuels; Oil and Gas Applications; Cycle Innovations

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“…These papers, therefore, did not deal with the problem of soot deposition at different oxygen concentrations. Previous studies of thermophoretic effects induced by temperature gradients have focused only on the thermophoretic effect on aerosols or tracer particles in gases or liquids (6) - (12) . These data are indispensable to elucidate the thermophoretic effect, but may be inadequate to establish the actual thermophoretic effect acting on soot particles in actual flames because of differences in particle morphology and chemical components of the particles.…”

Section: Introductionmentioning

confidence: 99%

A Study of the Effect of Oxygen Concentration on the Soot Deposition Process in a Diffusion Flame along a Solid Wall by In-Situ Observations in Microgravity

Choi

Fujita

Tsuiki

et al. 2005

JSME international journal. Ser. B, Fluids and thermal engineer

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The effect of oxygen concentration on the soot deposition process from a diffusion flame to a solid wall was investigated in a microgravity environment to attain in-situ observations of the process. An ethylene (C 2 H 4 ) diffusion flame was formed around a cylindrical rod burner in oxygen concentrations of O 2 = 21, 35, and 50% with a surrounding air and wall temperatures of 300 K. Laser extinction was adopted to determine the soot volume fraction distribution between the flame and burner wall. The experimental results show that the soot particle distribution region moves closer to the surface of the wall and that more deposition occurs with increasing surrounding oxygen concentrations. The experiments determined the trace of the maximum soot concentration position, defined as the "soot line", and it was comparable to that established with numerical calculations. A numerical simulation was also performed to understand the motion of soot particles in the flame and the characteristics of the soot deposition to the wall. The results successfully predicted the differences in the motion of soot particles by different oxygen concentrations near the burner surface and are in good agreement with observed soot behavior, ie the "soot line", in microgravity. A comparison of the calculations and experimental results led to the conclusion that a consideration of the thermophoretic effect is essential to understand the soot deposition on walls.

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Inertial effects on thermophoretic transport of small particles to walls with streamwise curvature—I. Theory

Konstandopoulos

Rosner

1995

International Journal of Heat and Mass Transfer

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Thermophoretic deposition near the leading edge of cylindrical surfaces

Cited by 4 publications

References 7 publications

Turbine Cascade Optimization Against Particle Deposition

Turbine Cascade Optimization Against Particle Deposition

A Study of the Effect of Oxygen Concentration on the Soot Deposition Process in a Diffusion Flame along a Solid Wall by In-Situ Observations in Microgravity

Inertial effects on thermophoretic transport of small particles to walls with streamwise curvature—I. Theory

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