Easy Explicit Coupling Between Two Large Codes Using CRAY UNICOS

Abstract

As in other areas of study, researchers on nuclear reactors often run into the need for coupling different types of scientific software to handle related problems in, say, neutronics, thermalhydraulics and mechanical engineering. Unfortunately, unless the software has a built-in link capability, the sheer size of it generally makes coupling difficult. This paper sets out a simple method for explicit software coupling using the facilities of the UNIX operating system. The coupled softwares run simultaneously and remain independent, exchanging data via "pipe" files. The only restriction to this method concerns the type of computer needed : this must operate under a UNIX operating system and be powerful enough to accommodate both of the software modules at the same time, This requirement is met by Electricite de France's CRAY-MCOS machine. Our first application involved coupling three-dimensional neutronics and thermalhydraulics calcu1ations using the COCCINELLE and THYC software, In view of the favorable results obtained, this method is considered suitable for routine use in this particular application and apt for extension to other applications.