ループ管方式熱音響冷却システムの実用化に向けた検討: 管の断面積が管内音場に与える影響

摘要

In this report, the experimental investigation of the inner diameter in the loop tube was carried out to confirm the effect for energy conversion efficiency. We carry out an experiment by using the loop tube with 3 type inner diameter (24 mm, 42 mm, 100 mm) for our purpose. As resuMIDs, a sound intensity, a sound pressure, a particle velocity and a phase difference between sound pressure and particle velocity was varied. In addition, it was confirmed that energy conversion efficiency in the loop tube changed with the variety of inner diameter on the loop tube. Energy conversion efficiency was improved most when we used the loop tube with inner diameter 100 mm. Furthermore, the temperature at the top part of a prime mover was 160℃ under the stationary state in this condition. We founded that the loop tube with 100 mm inner diameter can drive at low temperature. It was estimated that factor of improvement of energy conversion efficiency was the phase difference between the sound pressure and the particle velocity and heat exchange area formed in the prime mover stack.%本報告では，ループ管の内径がエネルギー変換効率に与える影響を確認するため，全長を一定にし，管の内径を24m，42mm，100mmの3種類を用い，実験を行った．測定の結果，管内に発生する音響インテンシティ，音圧，粒子速度，音圧と粒子速度の位相差が変化した．また，内径の変化に伴いエネルギー変換効率が変化したことを確認した．内径100mmのループ管において，エネルギー変換効率は最も向上した．更に内径100mのループ管はプライムムーバスタック上端の定常状態における温度は160℃となり，低温度での駆動に成功した．エネルギー変換効率の向上は，管内に形成される音圧と粒子速度の位相差分布やプライムムーバスタック内に形成される熱交換面積が関係していると推測された．