1. Renewable Energy Utilization Research Unit, Kyushu University Platform of Inter/Transdisciplinary Energy Research, 6-1 Kasuga-Koen, Kasuga 816-8580, Japan e-mail:
2. Professor Winder Engineering Division, Research Institute for Applied Mechanics, Kyushu University, 6-1 Kasuga-Koen, Kasuga 816-8580, Japan e-mail: