Design and Analysis of OTEC’s Cold Water Pipe

The Ocean Thermal Energy Conversion (OTEC) Program of the Department of Energy (DOE) is developing an engineering design manual for the OTEC Cold Water Pipe (CWP). Nominal dimensions of the pipes now under study have lengths to 1,000 meters, diameters of 9 meters and thicknesses ranging from 0.07 to 0.6 meters, depending on materials. Under the action of unsteady, three-dimensional hydrodynamic loads, as well as loads due to coupled surface platform motions, the CWP is subject to a combination of bending, torsional, and ovaling modes of oscillation. The CWP Engineering Design Manual will contain essential information and analytical models for CWP design and design assessment. This paper focuses on the problem of CWP structural analysis and describes CWP hydrodynamic loading forces and existing linear elastic beam CWP structural models. Sample calculations are presented which illustrate structural response predictions for the CWP in typical seas and demonstrate tentative agreement for a limited range of parameters between the three most widely used CWP structural models and the scant existing experimental data. 1980 OOE (Office of Ocean Engineering) Library Public Domain 1930