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This article reports a full-scale structural simulation of flow-induced mechanical noise in a 5-stage centrifugal pump. An interior flow field is simulated by a LES-based CFD code individually, which can be found elsewhere. This paper focuses on data interface, and a structural vibration analysis. We developed a data interface tool to enable mesh match as well as data interpolation between fluid and structure meshes. The vibration of a structural portion is simulated using a parallel explicit dynamic FE code, providing the time series of fluctuating pressure on internal surface as force boundary conditions. The calculated vibration of outer surface of the structure agrees reasonably well with measured one. By Fourier transformation, the vibration modes at the blade passing frequencies were extracted and visualized. The simulation clarified the mechanisms of resonant noise generation and propagation.

The effects of inner rotating plate on the heat transfer in a differentially heated inclined enclosure were investigated experimentally. The aspect ratio of the enclosure height/width was 1 throughout the experiments. An acrylic plate was installed with horizontal axis at the center of the square enclosure, and was rotated at various speeds. The inclination angle of the enclosure was varied from -90° to 90°. Purified water was used for the working fluid. The flow pattern was sketched by a visualization experiment using aluminum powder. The heat transfer enhancement can be clearly seen for the inclined enclosure with hot wall of downward facing. The rotating plate used here is useful for the regulation of wide-ranging heat transfer rate.

The effects of inner rotating plate with horizontal axis on the heat transfer between vertical two wails in a rectangular enclosure with stratified fluid layers were investigated experimentally. The aspect ratio of the enclosure height/width was 1 throughout the experiments. An acrylic plate with small thermal conductivity was installed horizontally at the center of the square enclosure, and was rotated at various speeds for normal and reverse rotations by using the motor attached outside of the enclosure. Purified water and silicon oil were used for the working fluid and were stratified in the enclosure. It is clarified here that the heat transfer rate of the enclosure with stratified fluid layers differs largely from that of the enclosure with single fluid layer. Namely, the heat transfer rate increases exceedingly at low rotating speed range, and keeps almost constant value at high rotating speed range.

The effects of inner rotating plate with horizontal axis on the heat transfer in a differentially heated vertical enclosure were investigated experimentally. The aspect ratio of the enclosure height/width was 1 throughout the experiments. An acrylic plate with small thermal conductivity was installed horizontally at the center of the square enclosure, and was rotated at various speeds for normal and reverse rotations by using the motor attached outside of the enclosure. Purified water was used for the working fluid. The flow pattern was sketched by a visualization experiment using aluminum powder. The heat transfer results were also compared with those for previous paper of rotating cylinder. It is clarified here that the heat transfer rate of the enclosure depends largely on the parameter Grw/Re2w, and is characterized by three regions. The heat transfer rate of enclosure with rotating plate is fairly larger than that of rotating cylinder in the forced convection region. The rotating plate used here will be useful for regulation of wide-ranging heat transfer.

An experimental study was conducted on the behavior of the fuel spray and the nozzle needle in a multihole valve cut orifice (VCO) nozzle for diesel engines. The measurements of time lag for fuel discharge among individual holes and the photographic observation of fuel sprays at an arbitrary instant after the start of fuel discharge were carried out using a video camera and a microflash. The magnified image of the top portion of the nozzle needle illuminated by an argon laser and two He-Ne lasers was observed using a high-speed video camera through a window of diameter 0. 6 mm installed at the nozzle tip. The results showed that the fuel spray was classified into solid cone, hollow cone and mixed types, and that the radial displacement of the nozzle needle was straight and toward the opposite side of the hole from which the earliest fuel spray appeared among the five holes.