Numerical Calculation of Three-Dimensional Interfacial Potential Flows Using the Point Vortex Method

A pre-fabricated welded tubular coupling particularly adapted for use in the construction of offshore platforms comprises a tubular elbow tangentially secured to a straight pipe segment solely along the line of intersection therebetween. A cutout or opening in the backwall of the elbow is configured to complementally receive a portion of the periphery of the pipe to enhance the integrity of the interconnection between the latter and the elbow. The opening has a marginal edge which defines a continuous line of contact with the pipe for welding of the components to form a unitary coupling. In preferred forms, the elbow presents a 90 DEG arc and is arranged such that each leg forms approximately a 45 DEG angle with the pipe. In another embodiment, the elbow extends through 135 DEG and is attached to the pipe in a manner to form approximately 90 DEG and 45 DEG angles between the respective legs and the pipe.