Counter-Rotating Type Tidal Stream Power Unit Boarded on Pillar(Performances and Flow Conditions of Tandem Propellers)

The authors have invented the unique counter-rotating type tidal stream power unit composed of the tandem propellers and the double rotational armature type peculiar generator without the traditional stator. The front and the rear propellers counter-drive the inner and the outer armatures of the peculiar generator, respectively. The unit has the fruitful advantages that not only the output is sufficiently higher without supplementary equipment such as a gearbox, but also the rotational moment hardly act on the pillar because the rotational torque of both propellers/armatures are counter-balanced in the unit. This paper discusses experimentally the performances of the power unit and the effects of the propeller rotation on the sea surface. The axial force acting on the pillar increases naturally with the increase of not only the stream velocity but also the drag of the tandem propellers. Besides, the force vertical to the stream also acts on the pillar, which is induced from the Karman vortex street and the dominant frequencies appear owing to the front and the rear propeller rotations. The propeller rotating in close to the sea surface brings the abnormal wave and the amplitude increases as the stream velocity is faster and/or the drag is stronger.

Acoustic Noise from Tandem Wind Rotors of Intelligent Wind Power Unit

The authors had invented the unique wind power unit composed of the large-sized front wind rotor,the small-sized rear wind rotor and the peculiar generator with the inner and the outer rotational armatures without the conventional stator.This unit is called "Intelligent Wind Power Unit" by the authors.The front and the rear wind rotors drive the inner and the outer armatures,respectively,while the rotational torque is counter-balanced between both armatures/wind rotors.This paper discusses experimentally the acoustic noise from the front and the rear wind rotors.The acoustic noise,in the counter-rotating operation,is induced mainly from the flow interaction between both rotors,and has the dominant power spectrum density at the frequency of the blade passing interaction.The noise is caused mainly from the turbulent fluctuation due to the flow separation on the blade,when the rear wind rotor stops or rotates in the same direction as the front wind rotor.

Turbo-pump with Isolated Two Stage Impellers for Future Rocket Engine (Trial to Drive Impellers Independently)

为了在 impellers 压制成穴并且做涡轮泵，更长生活， inducer 与主要 impeller 被分开，两 impellers 独立地被驾驶。在 impellers 附近的泵和流动条件的表演试验性地被调查，下列结果被获得。(1 ) 主要 impeller 贡献在 inducer 和主要 impeller 之间的流动相互作用。(2 ) 两 impellers 的旋转速度能独立地被控制以便同时总体上压制成穴不仅 impeller，而且在 inducer。