HPCCP/Numerical Propulsion System Simulation 
Steady State Cycle Deck Launcher

Objective: To rduce the time and cost of generating aerothermal numerical representations of engines called customer decks that are delivered to the airframe companies by various US engine companies. These customer decks numerically characterize the engines performance as defined and needed by the US airframe manufacturers. Until recently, all numerical models have been provided with a Fortran compatible interface which is defined in SAE document AS681F. Data Communication has been previously performed via a standard, labeled common structure per AS681F. The SAE committee has begun to develop a new standard: AS681G. AS681G addresses multiple language requirements for customer decks along with alternative data communication techniques.

Approach: The Numerical Propulsion system Simulation (NPSS) Steady State Cycle Deck (SSCD) project team with the SAE committee has developed a standard Application Program Interface (API) supported through a graphical user interface. This work will result in Aerospace Recommended Practice 4868 (ARP4868). The SSCD work will be validated against the Energy Efficient Engine (EEE) customer deck which is publicly available. The EEE wrapper is used not only to validate ARP4868 but also to demonstrate how to wrap an existing customer deck. The graphical user interface for the SSCD is used to facilitate the use of the new standard and to ease the ability to design and analyze a customer deck. The software will be developed following I. Jacobson's Object-Oriented Design methodology and implemented in C++.

Significance: The AS681G standard will establish a generic interface common amongst the US engine companies and airframe manufacturers. The benefit of this will lead to more accurate cycle models, quicker model generation and faster validation to specifications. The standard will facilitate teaming within Industry and NASA.

Accomplishments: The Numerical Propulsion System Simulation Steady State Cycle Deck team released a batch version in March 1996. Version 1.0 was released in June 1996.

Status/Plans: During FY1997, NPSS will accept enhancements and modifications to the Steady State Cycle Deck launcher. Consistent with NPSS' commercialization plan, these modifications will be done by a third party software vendor positioned for long term software support.

Contact: Don VanDrei
         NASA Lewis Research Center
         dvandrei@lerc.nasa.gov
         (216)433-9089