TRANSIENT PROCESSES IN DEEP-SEA PIPELINES

Transient processes in a deep-sea pipeline occurring (luring its transfer from one equilibrium state to another are investigated. The pipeline is regarded as a flexible rod of annular cross-section subjected to the action of the internal flow of slurry (pulp) and the external flow of the ambient liquid (the flow is assumed to be irrotational). The pipeline is hinged at the upper point with a movable floating unit and at the lower point to a buffer unit (end mass). An asymptotic solution of nonlinear dynamic problems for deep-sea pipelines related, in general, to the class of nonlinear singularly perturbed boundary value problems with nonlinear boundary conditions is obtained by means of the method of matching asymptotic expansions. The numerical integration of the simplified equations of the system dynamics is performed by the method of lines.