Abstract: A rotor is rotatably supported in a gantry housing having a substantially sealed structure. An X-ray tube is provided in the rotor. A cooler is provided in the rotor and cools a refrigerant within the X-ray tube. An X-ray detector is provided in the rotor. A reconstruction unit reconstructs an image on the basis of an output of the X-ray detector. A radiator is fixed inside the gantry housing at a position opposite to an exhaust opening of the cooler when the rotor is stationary.

Abstract: According to the invention, an X-ray CT apparatus includes: an annular rotator including: an X-ray tube; an X-ray detector disposed oppositely to the X-ray tube; a radiator disposed in the vicinity of the X-ray tube and dissipating heat from the X-ray tube; an air outlet provided in the vicinity of the radiator; and an air inlet provided at a position oppositely to the air outlet, a gantry cover covering peripheral of the annular rotator and having an upper air vent and a plurality of lower air vents; a plurality of fans discharging to the outside air exist in a gap between the gantry cover and the annular rotator from the air outlet; and a baffle plate provided in the gap in the vicinity of the lower air vents and controlling an air flow passing through internal space of the annular rotator and an airflow passing through the gap.

Abstract: The numerical analysis system of the invention analyzes the dynamical state of the compressible fluid employing Hybrid Grid Adaptation Method by Finite Volume Method. The initial grid data are created by way of free combination of tetrahedral cells, hexahedral cells and pentahedral cells. The divide-delete index is calculated according to the density of the fluid in each cell. A triangular face of the cell is divided into triangular faces and the quadrilateral face is divided into quadrilateral faces when the cell is divided. The cell is divided only when three conditions are satisfied. The first condition is that the volume of the cell is greater than the minimum volume. The second is that the dividing level of the cell is not the maximum level. The third is that the divide-delete index is greater than the dividing threshold.

Abstract: The numerical analysis system of the invention analyzes the dynamical state of the compressible fluid employing Hybrid Grid Adaptation Method by Finite Volume Method. The initial grid data are created by way of free combination of tetrahedral cells, hexahedral cells and pentahedral cells. The divide-delete index is calculated according to the density of the fluid in each cell. A triangular face of the cell is divided into triangular faces and the quadrilateral face is divided into quadrilateral faces when the cell is divided. The cell is divided only when three conditions are satisfied. The first condition is that the volume of the cell is greater than the minimum volume. The second is that the dividing level of the cell is not the maximum level. The third is that the divide-delete index is greater than the dividing threshold.