本研究は，多角形眼を伴っていた台風Songda (2004) の現実事例について，NCAR (National Center for Atmospheric Research)/ NCEP (National Centers for Environmental Prediction)において開発された領域気象モデルWRFを用いて再現し，壁雲周辺の力学的不安定の量を定量的に知るためにエネルギー解析を行った。その結果，対流圏下層ではメソ渦に起因するエネルギーのやり取り，中・上層では局所的な非断熱加熱に起因するエネルギーのやり取りが示唆された。また，下層のエネルギー変換率量と眼の壁雲の波数との間に密接な関係性があるという結果が得られた。 ; In this study, we simulate Typhoon Songda(2004) which had a polygonal eyewall with a regional atmospheric model to elucidate the spatial distribution of each energy and energy conversion around its eyewall under a realistic meteorological setting. The simulated results indicate that there were energy exchange produced by mesovortices in the lower layer of the troposphere and by diabatic heating in the middle and the upper layer. We conclude that there is a close relationship between the energy conversion and the wavenumber of typhoon eyewall in the lower layer of the troposphere. ; 本研究は，多角形眼を伴っていた台風Songda (2004) の現実事例について，NCAR (National Center for Atmospheric Research) / NCEP (National Centers for Environmental Prediction)において開発された領域気象モデルWRFを用いて再現し，壁雲周辺の力学的不安定の量を定量的に知るためにエネルギー解析を行った。その結果，対流圏下層ではメソ渦に起因するエネルギーのやり取り，中・上層では局所的な非断熱加熱に起因するエネルギーのやり取りが示唆された。また，下層のエネルギー変換率量と眼の壁雲の波数との間に密接な関係性があるという結果が得られた。 ; In this study, we simulate Typhoon Songda(2004) which had a polygonal eyewall with a regional atmospheric model to elucidate the spatial distribution of each energy and energy conversion around its eyewall under a realistic meteorological setting. The simulated results indicate that there were energy exchange produced by mesovortices in the lower layer of the troposphere and by diabatic heating in the middle and the upper layer. We conclude that there is a close relationship between the energy conversion and the wavenumber of typhoon eyewall in the lower layer of the troposphere.