Two-dimensional transient flow analysis of a pipe-elbow loop by finite-differences

A two-dimensional mathematical model that describes the transient flow in an elbow of a circular cross-section in terms of the r and $theta$ coordinates and ignores the motion of the fluid normal to the r-$theta$ plane is considered to approximate the flow in an elbow of any angle. The equations developed are solved numerically using the finite-difference method as applied to the basic Implicit Continuous-Fluid Eulerian (ICE) technique. The elbow model is incorporated with the two-dimensional circular pipe model in one computer code that is capable of analyzing the transient compressible flow of fluids in a loop consisting of straight pipes and elbows of any angle connected in series and subject to two different pressure pulses P(t) at both ends. The pipe walls can be either rigid or elastic-plastic walls, while those of the elbows can only be rigid. 9 refs