Simulation of Turbomachinery Flows on 10-50 GFLOP Testbeds




Objective:

To permit overnight turnaround of multistage turbomachinery simulations
through the use of scalable parallel architectures in solving the
Average-Passage model.  The goal in computing these simulations is to yield
the overall performance map for a given machine on a daily basis.


Approach:

Develop a multi-level parallel version of APNASA, which implements the
Average-Passage flow model for multistage turbomachinery.  The code would
initially allow for overnight turnaround of a compressor operating point by
utilizing both coarse (inter blade row) and fine grain (intra blade row)
parallelism to process multistage simulations.  Continued software and
hardware improvements will lead to overnight turnaround of an overall
performance map.


Accomplishment:

The code has been used to simulate a wide variety of turbomachinery
hardware, including multistage compressors consisting of over a dozen
stages.  One design exercise involved the simulation of an advanced 11+1/2
stage compressor designed by Pratt and Whitney for their 4000 engine
series.  Another design effort with the Allison Gas Turbine Engine Company
simulated a 14+1/2 stage axial flow compressor.  In each case an operating
point was able to be simulated within 24 hours using the HPCCP IBM SP2
(babbage).


Status/Plans:

With an upper bound of 150 user accessible processors, a peak of 4.3 GFLOPS
has been achieved when running APNASA on the HPCCP IBM SP2 (babbage).
Future plans call for demonstrating 10+ GFLOP performance in under 8 hours
turnaround time when simulating a compressor operating point.  This could
be accomplished through the use of larger testbed systems, such as the 384+
node IBM SP2 system located at the Maui High Performance Computing Center.
With the ability to simulate multiple operating points within a several
hour time frame, an overall performance map can be realistically computed
overnight.


Richard Mulac,  NYMA, Inc.
NASA Lewis Research Center
MS 5-9, 21000 Brookpark Road
Cleveland, Ohio  44135
(216) 433-5936
mulac@lerc.nasa.gov