عنوان مقاله [English]
نویسندگان [English]چکیده [English]
Hydraulic performance in simple culverts, which have constant cross sectional shape and slope is known. The headwater level at the inlet to a culvert is determined by the position of the control point. In simple culverts, the control point is either at the inlet or outlet. In some countries, like England, in response to the needs of industrial and urban development, rivers and streams have been progressively roofed over or culverted, which have different slope and
"cross - sectional shape. There are many factors which made the culverts complex and their hydraulic performance is not readily determinable. An experimental study of the hydraulic behavior in a culvert model which comprised of two consecutive barrels of different cross - sectional shape led to the conclusion that performance is influenced by such change of "section when it causes a movement of the control point position or changes of the point of"
priming, which can be caused by some complexity features like change of section. This influence can not be easily predicted. Besides inlet and outlet control as in simple culverts, there may be another control inside the complex culverts. The flow can be quite complicated: some section may run full and other partially full; sections of gradually-varied flow may be separated by sections of rapidly varied flow; one or more hydraulic jump may occur.