This article presents application of an adjoint method to the aerodynamic shape optimization of deflector vanes installed in the fan nozzle of a turbofan engine. The purpose of the vanes is to reduce jet noise radiated towards the community, and the specific application of this study is for a supersonic turbofan engines with bypass ratio 2.7. The cost function used in the optimization includes ...

This paper presents a work availability perspective on the thermodynamic performance of the turbofan engine and contrasts this with the classic presentation, which describes performance based primarily on cycle efficiency. It is shown that the availability perspective leads to a more fundamental understanding of the basic problem, this being to maximize the conversion of work potential stored i...

In this paper we describe an application of a robust identification approach to a turbofan engine. The approach combines classical time-data system identification via prediction error models and the so-called model error model theory. The model error model approach provides guidelines for the characterization of the model uncertainty stemming from the nominal system identification and fits natu...

Experimental results are presented on a method that eliminatesMach waves from the exhaust of supersonic jets and,hence, that removes a strong component of supersonic jet noise. Eliminationis achievedby surrounding the jet with an annular stream at prescribed velocity and temperature so that all turbulent motions become intrinsically subsonic. No mechanical suppressors are used. Implementation o...

The paper describes the results of numerical study of flow in the exhaust jet of turbofan engine CFM 56-3. Influence of computational domain decomposition, grid refinement and flow model on the jet flow field is discussed. Special attention is payed to simulation of nucleation and condensation processes in the exhaust jet. Growth of water clusters in the jet and cluster distribution in size are...

Engine health monitoring has been an area of intensive research for more than three decades. Numerous methods have been developed with the goal of determining a faithful picture of the engine condition. It becomes largely admitted that a practical implementation of a monitoring tool will rely on an adequate fusion of some techniques. In this framework, the present contribution proposes an origi...

There are at least two challenges that the jet engine noise community is currently facing. One challenge is due to existing engines that are being extended to higher power ratings without increasing the passive noise control treatment area. The second challenge comes about with the increasing trend to go to ultra-high bypass engines. This increases the importance of the fan tone noise and at th...

This paper presents an application of the recently developed theory of language-measure-based discrete event supervisory (DES) control to aircraft propulsion systems. A two-layer hierarchical architecture is proposed to coordinate the operations of a twin-engine propulsion system. The two engines are individually controlled to achieve enhanced performance and reliability, as necessary for fulfi...