Scientific and Technical Aerospace Reports Volume 38 July 28, 2000

performance required for a proposed mission. A three-dimensional CAD geometry was produced from the two-dimensional flowpath
for aerodynamic analysis, structural design, and packaging. The aerodynamics, engine performance, and mass properties arc
inputs to the vehicle performance tool to determine if the mission goals were met. If the mission goals were not met, then a flowpath
and vehicle redesign would begin. This design process might have to be performed several times to produce a ”closed” vehicle.
This paper will describe an attempt to design a hypersonic cruise vehicle propulsion flowpath using a Design of’ Experiments
method to reduce the resources necessary to produce a conceptual design with fewer iterations of the design cycle. These methods
also allow for more flexible mission analysis and incorporation of additional design constraints at any point. A design system was
developed using an object-based software package that would quickly generate each flowpath in the study given the values of the
geometric independent variables. These flowpath geometries were put into a hypersonic propulsion code and the engine performance
was generated. The propulsion results were loaded into statistical software to produce regression equations that were combined
with an aerodynamic database to optimize the flowpath at the vehicle performance level. For this example, the design
process was executed twice. The first pass was a cursory look at the independent variables selected to determine which variables
are the most important and to test all of the inputs to the optimization process. The second cycle is a more in-depth study with
more cases and higher order equations representing the design space.
Author
Fabrication; Air Breathing Engines; Applications Programs (Computers); Computer Aided Design; Design Analysis; Experiment
Design; Structural Design
20000063377 NASA Glenn Research Center, Cleveland, OH USA
The Numerical Propulsion System Simulation: An Overview
Lytle, John K., NASA Glenn Research Center, USA; June 2000; 14p; In English; Computational Aerosciences, 15-17 Feb. 2000,
Moffett Field, CA, USA; Sponsored by NASA Ames Research Center, USA
Contract(s)/Grant(s): RTOP 509-10-11
Report No.(s): NASA/TM-2000-209915; E-12152; NAS 1.15:209915; No Copyright; Avail: CASI; A03, Hardcopy; A01, Microfiche
Advances in computational technology and in physics-based modeling are making large-scale, detailed simulations of complex
systems possible within the design environment. For example, the integration of computing, communications, and aerodynamics
has reduced the time required to analyze major propulsion system components from days and weeks to minutes and hours.
This breakthrough has enabled the detailed simulation of major propulsion system components to become a routine part of designing
systems, providing the designer with critical information about the components early in the design process. This paper
describes the development of the numerical propulsion system simulation (NPSS), a modular and extensible framework for the
integration of multicomponent and multidisciplinary analysis tools using geographically distributed resources such as computing
platforms, data bases, and people. The analysis is currently focused on large-scale modeling of complete aircraft engines. This
will provide the product developer with a ”virtual wind tunnel” that will reduce the number of hardware builds and tests required
during the development of advanced aerospace propulsion systems.
Author
Propulsion System Performance; Propulsion System Configurations; Complex Systems; Mathematical Models; Simulation
20000064592 General Electric Co., Aircraft Engines, Cincinnati, OH USA
High Bypass Turbofan Compressions System Simulations Using 3D, Parallel, Multistage CFD
Dailey, Lyle D., General Electric Co., USA; Turner, Mark G., General Electric Co., USA; February 2000; In English; See also
20000064579; No Copyright; Abstract Only; Available from CASI only as part of the entire parent document
A parallelized set of analysis tools for turbofan system components is being used to simulate the aerodynamics through a GE
high bypass turbofan compression system. The compression system has been analyzed in multiple components to improve the
understanding of each individual component, as well as the interactions between components. These components include isolated
blade rows, isolated stages, the fan, the low pressure compressor (or booster), and blocks of the high pressure compressor (HPC).
Simulations are also planned to couple various components, such as the fan and booster and all blocks of the HPC, and to couple
the entire system, comprised of fan, booster, and HPC. The individual component simulations were validated by running at respective
rig conditions and comparing to rig test data. The full system simulation, which will be run at engine takeoff operating conditions,
will be validated with limited test data from static turbofan tests, and by comparing the computed shaft horsepower to the
engine cycle. These large-scale simulations have been made possible by utilizing parallel computing in the pre-processing and
flow solver tools. The grid generation tool used for these simulations, developed at NASA Glenn Research Center, is called APG.
by running APG in parallel, the grids for any component can be completed in about 20 minutes by using multiple processors. The
flow solver was originally developed by John Adamcyzk’s team at NASA Glenn, and later parallelized and made multiblock by
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