| Summary: | 博士 === 國立臺灣大學 === 應用力學研究所 === 84 === A joint numerical and experimental study of a uniform incoming
flow past a hill or twin hills has been invetigated. The finite
difference method is used in the numerical study. The
experimental work are conducted in a towing tank and an
unsteady wind tunnel. This study mainly includes three topics:
1.A homogeneous and stratified flow past a two dimensional
hill. 2.A homogeneous and stratified flow past two dimensional
twin hills. 3.A homogeneous and stratified flow past a three
dimensional hill. The second topic of three topics opens the
study of airflow past a group of hills. The present study for
flows past a group of hills is more toward to the practical
application because a group of hills and a basin topography
exist everywhere in nature. Due to the disturbance of the
topography, the flow are very complicated in windward, leeward
and vally regions when the incoming flow encounters a hill-
shaped obstacle. The numerical simulation is mainly used to
analyze the complicated flow and to investigate the important
differences between homogeneous and stratified flows. The
experimental results in homogeneous flows can be used not only
to analyze qualitatively the flow phenomena but also to
validate the numerical simulation. In addition, the connection
between the flow structures and drag forces exerted on the hill
are also revealed by numerical simulation. Furthermore, the two
dimensional numerical simulation are also examined by another
numerical method.
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