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The phase-averaged flow characteristics around a forward-swept axial fan model were investigated using a two-frame PTV method. The velocity fields in the sagittal and axial planes show clearly the periodic variations of flow structure and periodic shedding of the tip and trailing vortices according to the fan blade phase.

A new cooling duct system was developed in order to increase the refrigerator performance in terms of uniform temperature distribution particle image velocimetry (PIV) and the commercial software FLUENT was used to compare the performance of the conventional cooling system with the new cooling system. The new cooling system effectively cooled the door basket region, thus increasing the uniformity of the temperature distribution in the refrigeration compartment.

The flow characteristics around a rotating axial fan were experimentally investigated using a phase-averaged PTV velocity field measurement technique. The axial fan has 5 forward-swept blades with a radius of 25 mm. Measurements were carried out at 4 axial planes and 4 radial planes perpendicular to the axis of rotation. For the axial plane measurements, one fan blade was divided into 4 different phases in order to analyze the flow structure according to blade phase. For each case, 500 instantaneous velocity fields were measured and ensemble averaged to obtain phase-averaged velocity vector fields and vorticity contours. In addition, measurements were carried out at two planes around the blade surface. Phase averaged velocity fields show periodic variations with respect to the blade phase. The periodic shedding of the tip vortex at the blade tip is also observed. The phase averaged velocity fields measured in the radial planes show periodic variations according to the fan phase and the distance from the fan. These experimental results can be used to validate numerical calculations and to understand the flow characteristics of forward-swept axial fans.

In the continuous hot-dip galvanizing process of steel strips, the snout has been installed at the entering region of feeding strip into the molten zinc (Zn) pot. However, evaporated Zn particles in the snout cause ash imperfection on the galvanized steel strip surface. In order to resolve this problem, the flow field inside the snout, both on the deoxidization gas flow above the free surface and the molten Zn flow in the Zn pot. has been investigated experientially. For a 1/10 scale water model, flow visualization and PIV (Particle Image Velocimetry) velocity field measurements were carried out at the strip speed V s =1.5 m/s Aluminum flakes (1 μm) and atomized olive oil (3 μm) were used as seeding particles to simulate the molten Zn flow and the deoxidization gas flow, respectively. As a result, the liquid flow in the Zn pot is dominantly influenced by the up-rising flow in diagonal direction caused by the rotating sink roll. For gas flow in front of the strip inside the snout, the large-scale vortex formed by the downward moving strip is dominant. In the rear side of the strip, a counter-clockwise vortex is formed and some of the flow following by the moving strip impinges on the free surface of molten Zn. The liquid flow in front of the strip is governed by the up-rising flow entering the snout, caused by the rotating sink roll. The moving strip affects dominantly the liquid flow behind the strip inside the snout and large amounts of liquid are entrained and followed the moving strip toward the sink roll. A thin boundary layer is formed on the front side due to the up-rising flow, however, a relatively thick boundary layer is formed in the rear side of the strip. Inside the snout, the deoxidization gas flow above the free surface is much faster than the liquid flow in the Zn pot. More ash imperfections are anticipated on the rear surface of the strip where larger influx flow moves toward the strip in the region near the free surface.

This paper presents the improvement of RF control system for PEFP (Proton Engineering Frontier Project). The upgrade design is based on the use of VME based MODBUS/TCP Multi-function board connected to the specific low level RF Controllers (LLRF) via distributed I/O modules and Serial communication modules. The control system was based on EPICS (Experimental Physics and Industrial Control System) from the end of 2004. Starting from release 3.14, it is possible to run the EPICS database on VMEBUS hardware with UNIX operating system. Installation and commissioning of the RF module is scheduled on 2005. Control system to integrated the RF System to the PEFP control system is implemented. Hardware, software and various applications are upgrade to support the operation of RF Control system [1]. In this paper, we describe control structure and scheme of the current RF Control System and upgraded one.