Engine Thermal Control for Improving the Engine Thermal Efficiency and Anti-Knocking Quality

In recent years, improving the engine fuel economy has been strongly required. To enhance engine thermal efficiency, it is important to improve the engine anti-knock quality and to decrease the engine cooling heat loss. To keep the compatibility with improving the anti-knock quality and reducing the cooling heat loss, it is important to analyze the thermal flow in the engine. This paper describes the thermal flow in the engine by using CAE and a single cylinder engine. It is shown that CAE can simulate engine thermal flow quantitatively. CAE can also demonstrate that cooling the upper part of the liner on exhaust side gives large effect on improving the anti-knock quality. This result is certified by conducting some tests with a single cylinder engine. 熱効率向上を目的としてｴﾝｼﾞﾝの熱エネルギー活用が求められている．本研究では，CAE(気流燃焼計算と構造熱計算)と実験を組み合わせることで，単気筒エンジンでの燃焼室周りの熱流れの解明を行った．その結果，性能と燃費が両立するﾉｯｷﾝｸﾞの改善手法は，ﾗｲﾅの排気側上部の冷却強化であることを明らかにした．