Many aircraft need to operate efficiently at more than one flight regime; for example, certain airframes are expected to perform in relatively high-speed cruise modes, as well as slower loitering scenarios. Unfortunately, an engine operates most efficiently when the exit velocity closely matches the speed of the...

Innovators at the NASA Armstrong Flight Research Center have developed a compressor-generator-motor turbojet design concept that integrates the generator with the aerodynamic blade structures of the compression section of turbomachinery. This reduces weight and volume...

The current steady-state performance-based system studies are not adequate to evaluate certain advanced technologies for the challenges associated with meeting the transient performance requirements without better definition and control of component operating margins. Additional...

This technology exploits the capabilities of additive manufacturing to attenuate the fan noise within the inlet or aft duct of a turbofan engine. The approach may be expanded to include auxiliary power units, environmental control systems, or other...

One of the more critical constraints to the continued growth of air traffic is the related concern regarding aircraft noise. This concern has resulted in increasingly stringent noise restrictions for airports, both nationally and internationally. One of the major stretch goals for NASA is to...

The Commercial Modular Aero-Propulsion System Simulation 40k (C-MAPSS40k) software package is a nonlinear dynamic simulation of a 40,000-pound (≈178-kN) thrust class commercial turbofan engine, written in the MAT-LAB/Simulink environment. The model has been tuned to capture the behavior of...

The purpose of this innovation is to reduce aircraft noise in the communities surrounding airports by significantly attenuating the noise generated by the turbomachinery, and enhancing safety by providing a containment barrier for a blade failure. Acoustic liners are used in today’s turbofan engines...

The Commercial Modular Aero- Propulsion System Simulation (CMAPSS) is a computer program for simulating transient operation of a commercial turbofan engine that can generate as much as 90,000 lb (≈0.4 MN) of thrust. It includes a power-management system that enables simulation of open- or...

The Modular Aero-Propulsion System Simulation (MAPSS) is a graphical simulation environment designed for the development of advanced control algorithms and rapid testing of these algorithms on a generic computational model of a turbofan engine and its control system. MAPSS is a nonlinear, non-real- time...

A collection of computer programs has been developed that implements a procedure for predicting multiple- puretone (MPT) noise generated by fan blades of an aircraft engine (e.g., a turbofan engine). MPT noise arises when the fan is operating with supersonic relative tip Mach No. Under this flow...

Broadband Fan Noise Prediction System (BFaNS) is a computer program that, as its name indicates, predicts the broadband noise generated by the fan stage of a turbofan engine. This noise is the sum of (1) turbulent- inflow noise, which is caused by turbulence impinging on leading edges of the...

TFaNS is a computer program that predicts the tone noise that emanates from the fan stage of a turbofan engine. With the help of this program, engineers working to reduce fan tone noise can study the effects of proposed design changes and are thus more likely to be successful in their...

V072 is a computer program that predicts the noise generated by the interaction between the rotor-blade wake (fan wake) and the stator vanes of a turbofan engine. The program is a combination of subroutines from prior NASA programs, with many added features.

The ADPAC software is a computational fluid dynamics (CFD) code for analysis of flows in turbomachines. The outstanding feature of ADPAC is the ability to solve the Navier-Stokes equations for complex three-dimensional (3D) flow fields that include multiple flow paths, and the modeling of...