3-DIMENSIONAL TRANSIENT HEAT-TRANSFER FROM A BURIED PIPE .1. LAMINAR-FLOW

A model is presented for heat transfer from a fluid in laminar flow in side a buried horizontal pipe. The top surface of the soil in which th e pipe is buried is horizontal and flat and is kept at a temperature l ower than the soil and the fluid temperatures. The problem is modelled as a transient three-dimensional process in cylindrical geometry. The solution is obtained using a string-intersected-boundary formulation and a three-level alternating-direction implicit finite difference met hod. The resulting equations were solved on a CDC Cyber 205 supercompu ter. The validity of the numerical scheme has been verified by compari son with an analytical solution for a simplified problem.