Momentum and thermal boundary-layer thickness in a stagnation flow chemical vapor deposition reactor
نویسنده
چکیده
Explicit expressions have been derived for momentum and thermal boundary-layer thickness of the laminar, uniform stagnation flows characteristic of highly convective chemical vapor deposition pedestal reactors. Expressions for the velocity and temperature profiles within the boundary layers have also been obtained. The results indicate that, to leading order, the momentum boundary-layer thickness is inversely proportional to the square root of the Reynolds number, while the thermal boundary-layer thickness is inversely proportional to the square root of the Peclet number. Values computed using the approximate expressions are compared directly with numerical solutions of the equations of motion and thermal energy equation, for a specific set of conditions typical of diamond chemical vapor deposition. Because values of the Lewis number do not vary significantly from unity for many different chemical vapor deposition systems, the expression derived here for thermal boundary-layer thickness may be used directly as an approximate concentration boundary-layer thickness.
منابع مشابه
Stagnation-point flow of a viscous fluid towards a stretching surface with variable thickness and thermal radiation
In the present analysis, we study the boundary layer flow of an incompressible viscous fluid near the two-dimensional stagnation-point flow over a stretching surface. The effects of variable thickness and radiation are also taken into account and assumed that the sheet is non-flat. Using suitable transformations, the governing partial differential equations are first converted to ordin...
متن کاملA simplified analytical model of diamond growth in direct current arcjet reactors
A simplified model of a direct current arcjet-assisted diamond chemical vapor deposition reactor is presented. The model is based upon detailed theoretical analysis of the transport and chemical processes occurring during diamond deposition, and is formulated to yield closed-form solutions for diamond growth rate, defect density, and heat flux to the substrate. In a direct current arcjet reacto...
متن کاملSpectral Quasi-linearization for MHD Nanofluid Stagnation Boundary Layer Flow due to a Stretching/Shrinking Surface
This article concentrates on the effect of MHD heat mass transfer on the stagnation point nanofluid flow over a stretching or shrinking sheet with homogeneous-heterogeneous reactions. The flow analysis is disclosed in the neighborhood of stagnation point. Features of heat transport are characterized with Newtonian heating. The homogeneous-heterogeneous chemical reaction between the fluid and di...
متن کاملTwo-phase Boundary Layer Flow, Heat and Mass Transfer of a Dusty Liquid past a Stretching Sheet with Thermal Radiation
The problem of two-phase MHD boundary layer flow, heat and mass transfer over a stretching sheet with fluid-particle suspension and thermal radiation has been studied. The effect of mass transfer in dusty fluid over a stretching sheet is considered for the first time. The governing equations are reduced to a set of non-linear ordinary differential equations under suitable similarity transforma...
متن کاملOptimized Conditions for Catalytic Chemical Vapor Deposition of Vertically Aligned Carbon Nanotubes
Here, we have synthesized vertically aligned carbon nanotubes (VA-CNTs), using chemical vapor deposition (CVD) method. Cobalt and ethanol are used as the catalyst and the carbon source, respectively. The effects of ethanol flow rate, thickness of Co catalyst film, and growth time on the properties of the carbon nanotube growth are investigated. The results show that the flow rate of ethanol and...
متن کامل