Acceleration of the FINE/Turbo CFD solver in a heterogeneous environment with OpenACC directives

Adapting legacy applications for use in a modern heterogeneous environment is a serious challenge for an industrial software vendor (ISV). The adaptation of the NUMECA FINE/Turbo computational fluid dynamics (CFD) solver for accelerated CPU/GPU execution is presented. An incremental instrumentation with OpenACC directives has been used to obtain a global solver acceleration greater than 2X on the OLCF Titan supercomputer. The implementation principals and procedures presented in this paper constitute one successful path towards obtaining meaningful heterogeneous performance with a legacy application. The presented approach minimizes risk and developer-hour cost, making it particularly attractive for ISVs.