Numerical Propulsion System Simulation: A Common Tool for Aerospace Propulsion Being Developed

The NASA Glenn Research Center is developing an advanced multidisciplinary analysis environment for aerospace propulsion systems called the Numerical Propulsion System Simulation (NPSS). This simulation is initially being used to support aeropropulsion in the analysis and design of aircraft engines. NPSS provides increased flexibility for the user, which reduces the total development time and cost. It is currently being extended to support the Aviation Safety Program and Advanced Space Transportation. NPSS focuses on the integration of multiple disciplines such as aerodynamics, structure, and heat transfer with numerical zooming on component codes. Zooming is the coupling of analyses at various levels of detail. NPSS development includes using the Common Object Request Broker Architecture (CORBA) in the NPSS Developer's Kit to facilitate collaborative engineering. The NPSS Developer's Kit will provide the tools to develop custom components and to use the CORBA capability for zooming to higher fidelity codes, coupling to multidiscipline codes, transmitting secure data, and distributing simulations across different platforms. These powerful capabilities will extend NPSS from a zero-dimensional simulation tool to a multifidelity, multidiscipline system-level simulation tool for the full life cycle of an engine

Object-oriented Technology for Compressor Simulation

An object-oriented basis for interdisciplinary compressor simulation can, in principle, overcome several barriers associated with the traditional structured (procedural) development approach. This paper presents the results of a research effort with the objective to explore the repercussions on design, analysis, and implementation of a compressor model in an object oriented (OO) language, and to examine the ability of the OO system design to accommodate computational fluid dynamics (CFD) code for compressor performance prediction. Three fundamental results are that: (1) the selection of the object oriented language is not the central issue; enhanced (interdisciplinary) analysis capability derives from a broader focus on object-oriented technology; (2) object-oriented designs will produce more effective and reusable computer programs when the technology is applied to issues involving complex system inter-relationships (more so than when addressing the complex physics of an isolated discipline); and (3) the concept of disposable prototypes is effective for exploratory research programs, but this requires organizations to have a commensurate long-term perspective. This work also suggests that interdisciplinary simulation can be effectively accomplished (over several levels of fidelity) with a mixed language treatment (i.e., FORTRAN-C++), reinforcing the notion the OO technology implementation into simulations is a 'journey' in which the syntax can, by design, continuously evolve

Common Analysis Tool Being Developed for Aeropropulsion: The National Cycle Program Within the Numerical Propulsion System Simulation Environment

The NASA Lewis Research Center is developing an environment for analyzing and designing aircraft engines-the Numerical Propulsion System Simulation (NPSS). NPSS will integrate multiple disciplines, such as aerodynamics, structure, and heat transfer, and will make use of numerical "zooming" on component codes. Zooming is the coupling of analyses at various levels of detail. NPSS uses the latest computing and communication technologies to capture complex physical processes in a timely, cost-effective manner. The vision of NPSS is to create a "numerical test cell" enabling full engine simulations overnight on cost-effective computing platforms. Through the NASA/Industry Cooperative Effort agreement, NASA Lewis and industry partners are developing a new engine simulation called the National Cycle Program (NCP). NCP, which is the first step toward NPSS and is its initial framework, supports the aerothermodynamic system simulation process for the full life cycle of an engine. U.S. aircraft and airframe companies recognize NCP as the future industry standard common analysis tool for aeropropulsion system modeling. The estimated potential payoff for NCP is a $50 million/yr savings to industry through improved engineering productivity

Design Space Exploration Study and Optimization of a Distributed Turbo-Electric Propulsion System for a Regional Passenger Aircraft

Electric propulsion systems are considered as one possibility to reach the ambitious goals of the European Union’s Flightpath 2050 with regards to greenhouse gas emissions and noise. It has been claimed in several publications that Distributed Electric Propulsion (DEP) offers significant improvement in aerodynamic efficiency and thus a reduction in structural weight of the wing and noise emissions as well as additional degrees of freedom concerning flight control. To not outweigh those advantages by heavier drivetrains, the components within the electric propulsion system have to be extremely lightweight, efficient and reliable at the same time. The German nationally funded project SynergIE evaluates DEP for a 70 PAX regional reference aircaft with two (SE-2), six (DEP-6) and twelve (DEP-12) propulsion units with a turbo-electric drivetrain layout. This study aims to quantify the effect on the specific block fuel consumption for the different numbers of propulsors based on Top Level Aircraft Requirements (TLARs). The approach contains a coupled electric drivetrain system model which is based on physically derived, analytical models for each component linking specific subdomains, e.g., electromagnetics, structural mechanics and thermal analysis. A genetic algorithm is applied to optimise the key performance indicators (KPIs) of the electric system, before the results are fed back to the aircraft sizing process. It has been identified that constraints such as installation space or architectural decisions such as the number of propulsors have significant influence on the drivetrain weight and efficiency and interact with the whole aircraft sizing process, esp. with reference to nacelleweight and drag and thus the block fuel consumption. The study shows that the DEP-6 and DEP-12 project aircraft both have a potential of reducing the specific block fuel consumption by approx. 4.2% and 5.8% respectively in case of direct driven propellers, while for a geared-drive scenario a total reduction of up to 7.6% in case of DEP-6 and 8.5% in case of DEP-12 is possible, all compared to the direct-driven baseline (BSL) aircraft SE-2