Department of Mechanical Engineering, Yazd University, Yazd, IRAN
The derivation and solution of the two and three dimensional dynamic equations for a small pipeline inspection gauge (Pig) through a liquid pipeline is the main aim of this work. These equations can be used for synthesis of speed controller of a pig by using a bypass port in Pig. Momentum and energy equations are employed to study the influence of flow field on the Pig’s trajectory. The pig is assumed to be a small rigid body with a bypass hole in its body. The variation of the diameter of the bypass port, which is controlled by a valve, is considered in this formulation. The path of the pig or geometry of the pipeline is assumed to be 2D and 3D curve. 2D and 3D simulations of the pig motion are performed individually and a case has been solved and discussed for each of them. The simulation results show that the derived equations are valid and effective for online estimating of the position, velocity and forces acting on the pig at any time of its motion.