Onyx: An object-oriented framework for computational simulation of gas turbine systems.

摘要

Computational simulation, using advanced analysis techniques such as computational fluid dynamics and finite element analysis, is likely to become the principle tool for complete gas turbine engine design in the near future. This is primarily due to the flexibility it provides for rapid and relatively inexpensive evaluation of alternative designs, and because it can be used to integrate multidisciplinary analysis earlier in the design process. This potential, however, can only be fully realized by the development of a software simulation system capable of integrating advanced multidisciplinary and multifidelity analysis methods, dynamically constructing arbitrary simulation models, and distributing computationally complex tasks.; This dissertation describes the design and development of Onyx , a Java-based object-oriented domain framework for gas turbine engine simulation. The Onyx framework defines a common component object model which provides a consistent component interface for the construction of hierarchal object models. Because Onyx is a framework, component analysis models may be changed dynamically to adapt simulation behavior as required. A customizable visual interface provides high-level symbolic control of propulsion system construction and execution. For computationally-intensive analysis, components may be distributed across heterogeneous computing architectures and operating systems.; As a representative example, a turbofan engine is simulated. The engine system is decomposed to give a hierarchically structured set of engine component models. Component behavior is defined by conservative aero-thermodynamic laws, which are space-averaged to provide a lumped-parameter mathematical model for each component. For transient operation, the unsteady equations for fluid momentum in ducts, inertia in rotating components, and mass and energy storage in inter-component mixing volumes are included. Overall performance maps are used to provide accurate steadystate representations of compressor and turbine component operation. A execution strategy is defined, along with a set of implicit solvers to provide both steady-state and transient simulations.