Heat and Mass Transfer of Impinging Jet Flow with Shower Head Flow on a Heated Disc in a Cylindrical Flow Channel

Abstract

The horizontal temperature measurement on the heated disc in the cylindrical hydrogen flow channel with impinging jet was performed to examine the effect of the non-dimensional distance between the gas inlet and the heated disc (HN*) and the nozzle Reynolds number (ReN) on the heat transfer in a chemical vapor deposition (CVD) reactor. Furthermore, two dimensional numerical simulation in heat and mass transfer on the heated disc was conducted to predict the growth rate distribution along the r-coordinate in the CVD reactor. The less HN* created, the lower the experimental temperature at r* = 0 mm because of the impinging jet flow. The calculation temperature along the r-coordinate agreed well with the experimental temperature except for HN* = 0.69 at r* = 0. When the non-dimensional surface reaction rate constant k* was 3.60×10-9 ≦ k*≦ 1.27×10-7 (k = 10-6 m/s), the predicted growth rate of the source material on the heated disc decreased exponentially with the r-direction because the film formation could proceed under the diffusion rate-determining condition along the radial direction. On the other hand, at the central region the influence of mass transfer due to forced convection discharged from the jet becomes stronger at 0.036 ≦ k*≦ 0.126 (k = 1 m/s) than that at 3.60×10-9 ≦ k* ≦ 1.27×10-7 (k = 10-6 m/s) and the film formation rate is greatly attenuated. The higher the distance from the nozzle to the heated disc HN got, the smaller the gradient of the growth rate in the r-direction at 0 ≦ r* ≦ 3.45 because the mass transfer could be controlled by the surface reaction if the HN* increased. The more the HN* and the less the reaction rate were constant, the smaller the coefficient of variation of the growth rate. In this study, the minimum coefficient of variation for the growth rate distribution was about 0.41. Therefore, it is suggested that the hybrid supply system of the raw material for chemical vapor deposition from not only impinging jet flow but also shower head flow could be suitable.