Laser induced thermophoresis and particulate deposition efficiency

Conference · Fri Jul 01 04:00:00 EDT 1983 · HTD (Publ.) (Am. Soc. Mech. Eng.); (United States)

OSTI ID:5236746

Cipolla, J; Morse, T F; Wang, C Y

The interaction of laser radiation and an absorbing aerosol in a tube flow has been considered. The aerosol is produced by external heating of reactants as in the MCVD (Modified Chemical Vapor Deposition) process to produce submicron size particles in the manufacture of optical fiber preforms. These are subsequently deposited by thermophoretic forces on the inner wall of the tube as they are convected by a Poiseuille velocity profile. Axial laser radiation in the tube interacts with the absorbing particles, and the laser heating of the gas induces additional thermophoretic forces that markedly increase the efficiency of particulate deposition. A particle concentration dependent absorption coefficient that appears in the energy equation couples the energy equation to the equation of particle conservation, so that a non-linear set of coupled partial integrodifferential equations must be solved. Numerical solutions for aerosol particle trajectories, and thus deposition efficiencies, have been obtained. It is shown that laser enhanced thermophoresis markedly improves the deposition efficiency.

• Research Organization: Northeastern University, Boston, Massachusetts
• OSTI ID: 5236746
• Report Number(s): CONF-830702-
• Conference Information: Journal Name: HTD (Publ.) (Am. Soc. Mech. Eng.); (United States) Journal Volume: HTD-VOL 23
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420400* -- Engineering-- Heat Transfer & Fluid Flow
ABSORPTION
AEROSOLS
COLLOIDS
DEPOSITION
DIFFERENTIAL EQUATIONS
DISPERSIONS
EFFICIENCY
EQUATIONS
FIBERS
FLUID FLOW
HEATING
LAMINAR FLOW
LASER-RADIATION HEATING
MANUFACTURING
NONLINEAR PROBLEMS
NUMERICAL SOLUTION
OPTICAL FIBERS
PARTIAL DIFFERENTIAL EQUATIONS
PARTICLE SIZE
PARTICLE TRACKS
PARTICLES
PARTICULATES
PLASMA HEATING
SIZE
SOLS
THERMOPHORESIS
TRAJECTORIES
TUBES
VELOCITY
WALLS