A Numerical Model of the Flow and Heat Transfer in a Rotating Disk Chemical Vapor Deposition Reactor

Abstract

Steady, laminar, axisymmetric, and circumferentially uniform flow and heat transfer, including the effects of variable properties and buoyancy, have been modeled within a rotating disk chemical vapor deposition (CVD) reactor. The reactor is oriented vertically, with the hot, isothermal, spinning disk facing upward. The Navier–Stokes and energy equations have been solved for the carrier gas helium. The solutions have been obtained over a range of parameters, which is of importance in CVD applications. The primary parameters are the ratio of the disk temperature to the free stream temperature Tw/T∞, the disk Reynolds number Re = rd2ω/ν∞, a mixed convection parameter Gr/Re3/2 = g(ρ∞ − ρw)/(ρwωων∞), the dimensionless inlet velocity u∞/ων∞, and two geometric parameters ro/rd and L/rd. Results are obtained for the velocity and the temperature fields and for the heat flux at the surface of the rotating disk. Comparisons are made with the one-dimensional, variable-property (excluding buoyant effects), infinite rotating disk solutions of Pollard and Newman. Results are presented in terms of a local Nusselt number. The potential uniformity of CVD in this geometry can be inferred from the variation of the Nusselt number over the surface of the rotating disk. The effects of buoyancy and the finite size of the rotating disk within the cylindrical reactor are clearly evident in the present work.

Massively parallel computation of 3D flow and reactions in chemical vapor deposition reactors

“…In the MPSalsa calculation, we solve the 3D problem for a disk of finite radius and examine solutions near the center of the disk. The second set of results is for the deposition of GaAs in a rotating disk reactor [6]. Our calculation is seen to match experimental results very well.…”

“…The rotating disk reactor is designed to take advantage of the perfect theoretical uniformity of the infinite disk configuration [8,6]. Figure 4 shows the geometry of this reactor, which consists of a cylindrical can placed concentrically within a larger cylindrical reactor.…”

“…An important CVD research thrust has been in detailed modeling of fluid flow and heat transfer in the reactor vessel, treating transport and reaction of chemical species either very simply or as a totally decoupled problem. For instance, a good understanding of the behavior of a vertical rotating disk reactor has been gained through fluid flow and heat transfer models that take advantage of the axisymmetry of the reactor to reduce the problem to two spatial dimensions [6,7]. Using the analogy between heat transfer and mass transfer, and the fact that deposition is often diffusion limited, much can be learned from these calculations; however, the effects of thermal diffusion, the change in physical properties with composition, and the incorporation of surface reaction mechanisms are not included in this model, nor can transitions to three-dimensional flows be detected [8].…”

Convective heat transfer and flow stability in rotating disk CVD reactors

“…In the current study, Rei, is not an independent parameter because we consider only cases where the inlet velocity is set equal to the asymptotic velocity for an infinite rotating disk: Ei, = C m , which gives ui, = C, where C is a function of the inlet temperature, Ti,, the disk temperature Td and the gas (Evans and Greif, 1987). Thus in this study, Rei, = BAG'=, and the dimensionless reactor wall…”

The influence of convective heat transfer on flow stability in rotating disk chemical vapor deposition reactors

“…In the current study, Rei, is not an independent parameter because we consider only cases where the inlet velocity is set equal to the asymptotic velocity for an infinite rotating disk Tiin = C m , which gives ui, = C, where C is a function of the inlet temperature, Ti,,, the disk temperature T d and the gas (see e.g. [3]). Thus in this study, Rei, = 2 A C G , and the dimensionless reactor wall temperature is…”