Methods for Optimisation and Acceleration of an Explicit Navier-Stokes Code with Application to Shock/Boundary-Layer Interaction

The two parts of this paper discuss techniques for improving the programming efficiency of explicit algorithms on the CRAY-1 vector computer at the Fortran and Assembler levels respectively. The high degree of modularity was essential for both simplifying the application of the techniques of vectorisation and for calculating the maximal execution speed of the algorithm and achieving this speed using assembly language.At the Fortran level increasing vector lengths by reducing the dimension of arrays achieved a performance improvement of between 10 % and 50 %, the module coded in assembly language a-chieved a further improvement of 37 %. The FORTRAN coded program attained an average speed of 60 MFLOPS.