Scientific and Technical Aerospace Reports Volume 38 July 28, 2000

GE. The simulations make use of the multiblock capabilities of APG and APNASA, allowing treatment of multiple flow regions,
such as the core flow, bypass flow, and bleed flows. The grid generator and flow solver have been run at GE on a networked system
of workstations. The flow solver is also commonly run on the NASA Origin system at NASA Ames. Performance of the flow
solver on the two systems will be compared. Additional information is contained in the original.
Author
Compressors; Computational Fluid Dynamics; Grid Generation (Mathematics); Parallel Processing (Computers); Turbofans;
Computerized Simulation
20000064598 General Electric Co., Aircraft Engines, Cincinnati, OH USA
Integrated Multidisciplinary Design
Bailey, Michael W., General Electric Co., USA; Irani, Rohinton K., General Electric Co., USA; Finnigan, Peter M., General Electric
Co., USA; Rohl, Peter J., General Electric Co., USA; Badhrinath, Krishnakumar, General Electric Co., USA; Welcome to the
NASA High Performance Computing and Communications Computational Aerosciences (CAS) Workshop 2000; February 2000;
In English; See also 20000064579; No Copyright; Abstract Only; Available from CASI only as part of the entire parent document
An integrated multidisciplinary approach to system design of aircraft engines has been the goal for many years. Frequently
referred to as concurrent engineering, this has been a predominantly manual process since the computer structure to support it has
been unavailable. Historically the approach has been to achieve this multidisciplinary integration by linking aerodynamic and
structural code inputs and outputs and typically generating geometry in the form of an IGES files as required. This approach does
not provide a seamless flow of information from Conceptual through to Preliminary, Detail Design and manufacturing. Simplification
at the Concept and Preliminary Design phases when commitments are made to the customer are often invalidated at the
Detail Design phase. This results in rework, sub-optimal designs and potentially low customer satisfaction. Master Model or Common
Geometry is a geometric centric approach that provides a linked associative environment from concept to manufactured product.
Here the intent is to create 3-Dimensional solid geometry at engine concept which would flow seamlessly into detail design,
digital engine mockup and manufacturing. This paper describes the move towards a more integrated CAD/CAM/CAE approach
based on the concept of a common geometric representation of the product being the design integrator. Everyone is familiar with
the concept of building up a system from its constituent parts. Less well understood is how the system level constraints and requirements
flow down to these parts with resultant feedback to the system. This has traditionally been the goal of concurrent engineering
but the degree of concurrency necessary to provide optimization at the system level has never been achieved. The ultimate goal
is an infrastructure that will support concurrent design by analysis. This will be complimented by robust design techniques which
use a probabilistic approach to account for the uncertainty associated with a design. GEAE is currently implementing a Common
Geometry infrastructure that will support the product from creation to manufacturing and ultimately engine services. This infrastructure
will also support the move from deterministic to probabilistic design. Several pilot projects have been successfully completed
paving the way to a successful initial implementation. An integral part of this whole process is CAD Integration with
Analysis where analytical models are created by applying boundary conditions to the same geometry using context models or
views of geometry. Manufacturing also uses the same geometry combined with context models to create in-process models. A
prerequisite in this is the creation of 3-Dimensional parametric feature based models. The goal is to significantly shorten the design
cycle not only by automation but by creating a degree of concurrency previously unachievable. Results from these pilots, the initial
implementation and the productivity gains demonstrated will be discussed. GEAE initiated the Common Geometry project two
years ago. The ground rules were that the system would be Unigraphics based and be implemented in commercial software wherever
possible. The Common Geometry environment should support the product creation from concept to manufacturing and ultimately
services. An integral part of the system would be a Product Data Management System (PDMS) which would support the
storage and retrieval of both data related directly to geometry and other metadata. This PDMS would permit the different activities
to function concurrently and permit updates to flow down to all aspects of the design activity. This paper will build on the approach
described in another publication. In every design there exists a performance floor and cost ceiling between which multiple solutions
exist. The purpose of a design is to create a product that will provide customer satisfaction in terms of expectations and technical
requirements. In the military world this is the ability to complete a specific mission and in the commercial world this is the
ability to produce a revenue stream. The challenge is to translate these customer Critical to Quality requirements into hardware
that will comprise a system. Consequently an understanding of the flowdown of the customer CTQ’s to individual parts is essential
if customer satisfaction is to be achieved. This represents the challenge in GEAE’s Design For Six Sigma Initiative and is driving
the shift from deterministic to probabilistic design methodologies. Common Geometry is a key enabling technology to achieving
these goals. Shortening the design cycle by designing by analysis and minimizing testing will significantly reduce engine develop-
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