Fundamental performance of triple magnetic circuit type cylindrical thermomagnetic engine

The engine essentially consists of a rotor made of temperature-sensitive magnetic material and permanent magnets. When an object made of this material has a temperature distribution in the magnetic field, the force is generated in the direction from the low-temperature side to the high-temperature side by magnetic pressure. This paper describes the fundamental performance of the triple magnetic circuit type thermomagnetic engine. A triple magnetic circuit type engine with water-cooling system has ben designed. The performance characteristics such as power, resistance loss, and the relation between the temperature of the rotor and the rotation speed have been measured, and compared with the characteristics of a single magnetic circuit type engine. The net power is a maximum value of 3.7 W at a rotation speed of 0.4 rps. The power of the triple magnetic circuit type engine per unit magnetic circuit is about 4 times larger than that of the single magnetic circuit type engine. The resistance loss is 1.7 W at the maximum power point. The total power is 5.4 W. Electromagnetic braking loss is about 25% of the total power. The rate of electromagnetic braking loss to the total power increases with the rotation speed. The disk type rotor with small electromagnetic braking loss has been analyzed . Electromagnetic braking loss of the disk type engine becomes about 95% smaller than that of the cylinder type engine. (c) 2006 Wiley Periodicals, Inc.