Estimation of Buoyancy Change of an NTE Capsule Using PCM

A new device which has negative thermal expansion behavior has been developed. One of the authors named it “NTE capsule” for short. The NTE capsule is expected to enhance the heat transfer moving up and down in a top-heated water tank. Recently the authors developed a new NTE capsule using Phase Change Material (PCM). The motion of it in a top-heated water tank has already been analyzed by numerical calculation and its motion has already been observed by operation experiment. In this study, the propriety of primitive design model was discussed. For this purpose, the buoyancy change of a NTE capsule using PCM was measured and compared to an estimated value by a primitive design model. As the result, the correction of the design model which gave the prediction of the more precise buoyancy change was shown.