ABSTRACT
This chapter discusses several forms of jets including plunging jets, submerged jets, horizontal and vertical jets, and two-dimensional and three-dimensional jets. Till date, however, there is no universal scour formula that is capable of handling the different flows downstream of hydraulic structures. The scour associated with hydraulic structures may be caused by different types of jets, including plunging jets that impinge on an erodible bed and horizontal jets eroding bed material immediately downstream of structures. In addition, a distinction can be made between plane and circular jets and between submerged and unsubmerged jets. Downstream of hydropower turbines, for example, the flow a bed protection generally consists of a supercritical part upstream, a hydraulic jump, and a subcritical part downstream.
