Particle image velocimetry measurement of jet impingement in a cylindrical chamber with a heated rotating disk

We studied the flow field of a jet impingement on a rotating heated disk to simulate the flow field surrounding the rotating disk of a chemical vapor deposition (CVD) reactor, which is widely used for large-scale production of thin-films and semiconductor materials. The flow field influences the growth rate and deposition uniformity, and is subject to the combined effects of buoyancy, centrifugal, and flow inertia forces that occur during the deposition process. The study investigated various flow-cell sizes and locations, such as the inlet flow-rate (1-10 slpm), jet-to-disk temperature difference (40-80 degrees C), and disk rotational speeds (0-500 rpm). Particle image velocimetry (PIV) was used to measure the flow-velocity field and flow-streamlines in the test chamber. The time-averaged axial and radial velocity profiles near the disk were used to determine the variations in flow velocity resulting from rotation and heating. Upward buoyancy forces, caused by the heated disk, produce flow cells and break the flow uniformity above the disk. When the rotational Reynolds number increases, the rotational effect eventually dominates the flow field that increases the flow velocity and generates flow cells near the chamber wall. Flow regime maps of these flow patterns were constructed, based on the Grashof number and rotational Reynolds number. (c) 2013 Elsevier Ltd. All rights reserved.