2. Continuous liquid flow

2.1 Flow in long cylindrical pipes

In what follows, we shall neglect the compressibility of liquids and consider a fluid with constant density ρ. We will examine its flow in a pipe of any cross-section, but independent of the abscissa, or cylindrical pipe. The notion of a long pipe is linked to the establishment of a flow regime in the pipe; in practice, this requires a length exceeding several tens of times the cross-sectional dimensions.

2.1.1 Flow shape and flow regimes

Under the conditions...