抄録
The purpose of this research is to clarify the requirements for the length of the SMA belt for a SMA engine. In order to put the SMA engine in practical use, maximizing the output power density is most important from the viewpoint of economic efficiency. In the former paper we showed that the output power of the SMA engine highly depends on the diameter of the SMA belt , the radius of the high-temperature wheel and the radius of the low-temperature wheel. In this study we will change the diameter of the SMA belt and theoretically explain whether there is a relational expression between the diameter and the length. If the length of the SMA belt is determined, the height of the SMA engine is also determined. Since the output of the SMA engine can be calculated by the already derived theoretical formula, we can divide it by the volume of the SMA engine and thus, calculate the output power density of the SMA engine. As the result, changing the diameter of the SMA belt, we can calculate the most appropriate value, at which the output power density of the SMA engine is maximal.