NUMERICAL-CALCULATIONS OF PARTICLE DEPOSI TION IN A LAMINAR-FLOW IMPINGING ONTO A FREESTANDING DISC

Increasingly process steps become important, in which particles as pro duct particles or contaminants are deposited on substrates out of the gas phase. In this paper the particles transport processes are investi gated close to the surface of a circular plate surrounded by a laminar flow. The analogy between the governing equations of momentum, energy and mass is applied to the extended diffusion equation. In the nondim ensional form the results of the numerical calculations give informati ons about velocity, temperature and particle concentration boundary la yer thickness as well as their distributions. Especially the impact of external forces on particle concentration boundary layer thickness an d profile is discussed. The transport of submicron particles to the su rface due to convection, diffusion, gravity and thermophoretic forces acting independently is investigated. In the used normalized form the different forces are acting as one resulting force independently of th eir origin. Their resulting effect in comparison to the effect due to convective diffusive transport is important for particle deposition.