Orr-Sommerfeld Computation and Database Package Last update: 2 Aug 04 Mark Drela, MIT Aero & Astro ============================================================================= Execute the following commands to enable OS-database lookup table routine. Start in the directory containing this README file. % pwd % cd src % edit osmap.f 1) Find the following line in osmap.f (roughly line 100) : DATA OSFILE / '/var/local/codes/orrs/osmap.dat' / Take the absolute directory string which is generated by the pwd command above, paste it in front of the osmap.dat filename, e.g. DATA OSFILE / '/usr/whatever/orrs/osmap.dat' / This statement will tell SUBROUTINE OSMAP where to find this table data file. 2) Find the following line in osmap.f (roughly line 75): REAL*4 RLSP, WLSP, HLSP, & RINCR, WINCR, RL, WL, HL, & A, AR, AW, AH, ARW, ARH, AWH, ARWH If you choose to use single-precision for the OS data file (should be adequate), leave this line as is. If you wish to do everything in double precision, change the REAL*4 to REAL. % cd ../bin % edit Makefile Change the compiler flags to match the Fortran compiler on your system. Use Makefile_DP for double-precision OS database file. % make osgen OR make -f Makefile_DP osgen % make osmap.o % cd .. % bin/osgen osmaps_ns.lst (creates binary file osmap.dat) SUBROUTINE OSMAP is now enabled. Programs which call it must be linked with the object file bin/osmap.o ============================================================================= Brief description of relevant files. osm.0220 osm.0230 osm.0240 osm.0250 osm.0260 osm.0270 osm.0280 osm.0300 osm.0320 osm.0350 osm.0400 osm_ns.0500 osm_ns.0600 osm_ns.0800 osm_ns.1000 osm_ns.1200 osm_ns.1500 osm_ns.2000 These contain the data defining the alpha(H,Re,w) function, in ascii format. Program osgen reads and collates this data into one binary file osmap.dat . Each file contains data from a constant-H "slice" through the (H,Re,w) space. The suffix indicates the H value: osm.0220 is for H=2.20 osm.0230 is for H=2.30, etc The mean-flow U(y) and dU/dy profiles which were used by the OS solver to generate each slice is contained in each osm.xxxx file near the top. SUBROUTINE READOS (src/io.f) can be used to extract these mean-flow profiles. The profiles in osm.0220 through osm.0400 are the Falkner-Skan similarity profiles for attached flow. The profiles in osm_ns.0500 through osm_ns.2000 are non-similar separated-flow profiles, which have smaller reverse flow velocities than the alternative Falkner-Skan profiles with the same H. The non-similar profiles are a better match to actual profiles found in typical separation bubbles. ============================================================================= Other useful routines. fs.f Generates Falkner-Skan profiles orrs.f Solves Orr-Sommerfeld spatial or temporal-stability problem