local news

INTRODUCTION

PREFACE A natural phenomenon that we all for sure can imagine is that when a coloured wind stream moves in parallel straight to the front of a pinwheel, that wind stream will become turbulent behind the pinwheel. The wind no longer moves in parallel as it does in front of the pinwheel (this can be easily tested with a smoke stream). The operation of the pinwheel is similar to that of a wind

Xem tiếp »