1. Mitsubishi Hitachi Power Systems, Ltd., Minatomirai 3-chome, Nishi-ku, Yokohama 220-8401, Japan
2. Mem. ASME Department of Mechanical Science Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan e-mail:
3. Department of Mechanical Science Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan