Multi-degree-of-freedom liner development: Concept to flight test

2021 ◽  
pp. 1475472X2110238
Author(s):  
Daniel L Sutliff ◽  
Douglas M Nark ◽  
Michael G Jones
Keyword(s):  
Fuel Efficiency ◽  
Evaluation Process ◽  
Flight Test ◽  
Experimental Models ◽  
Degree Of Freedom ◽  
Research Mission ◽  
Acoustic Signature ◽  
Acoustic Liner ◽  
Readiness Level ◽  
Optimization Methodology

The emphasis on increased turbofan fuel efficiency requires advanced turbofan designs that will integrate higher engine bypass ratios and shorter nacelles. The resulting acoustic signature of these designs will have a more broadband character as well as a smaller available area for liner installation. This two-fold impact compels a need for an improvement in the state of the art in liner technology. Increasing the acoustic absorption efficacy over a broader frequency range is a means to address this need. An acoustic liner development and optimization process was conceived and employed to achieve and demonstrate an improved broadband liner design concept. A series of increasing technology readiness level liner studies were conducted to enhance the optimization methodology while validating the concept. This progression spanned several NASA Aeronautics Research Mission Directorate programs/projects due to its relevance. This article reviews the development and evaluation process of the multi-degree-of-freedom liner technology concept from formation through simple experimental models to a flight test over an approximate 10-year period, focusing on the discrete tests comprising the development.

Investigations of three over-the-rotor liner concepts at various technology readiness levels

2021 ◽  
pp. 1475472X2110258
Author(s):  
Daniel L Sutliff ◽  
Richard F Bozak ◽  
Michael G Jones ◽  
Douglas M Nark
Keyword(s):  
Near Field ◽  
Fuel Efficiency ◽  
Engine Performance ◽  
Evaluation Process ◽  
Significant Advance ◽  
Technology Readiness ◽  
Acoustic Liners ◽  
Acoustic Signature ◽  
Readiness Level ◽  
Generation Mechanisms

The emphasis on increased turbofan fuel efficiency requires advanced turbofan designs that will integrate higher engine bypass ratios and shorter nacelles. The resulting acoustic signature of these designs will have a more broadband character as well as a smaller available area for liner installation. This two-fold impact compels a need for an improvement in the state of the art in liner technology. Increasing the acoustic absorption efficacy over a broader frequency range is a means to address this need. NASA investigated over-the-rotor acoustic liners for turbofan applications as a potential solution. This type of liner represents a significant advance over traditional liners due to placement in close proximity to the rotor. An advantage of placing treatment in this region is a modification of the acoustic near field, thereby inhibiting noise generation mechanisms. This can result in higher attenuation levels than could be achieved by the conventional sound absorption means. In addition, there is potential to integrate the liner with fan rub-strip and containment components, reducing engine components and thus weight, enabling a systematic enhancement in noise reduction and engine performance. This article reviews the development and evaluation process of three unique over-the-rotor concepts focusing on the discrete tests conducted across the Technology Readiness Level span.

An acoustic liner design methodology based on a statistical source model

2021 ◽  
pp. 1475472X2110238
Author(s):  
Douglas M Nark ◽  
Michael G Jones
Keyword(s):  
Design Methodology ◽  
Three Dimensional ◽  
Aircraft Engine ◽  
Flight Test ◽  
Source Model ◽  
Practical Implementation ◽  
Source Information ◽  
Fan Noise ◽  
Future Design ◽  
Acoustic Liner

The attenuation of fan tones remains an important aspect of fan noise reduction for high bypass ratio turbofan engines. However, as fan design considerations have evolved, the simultaneous reduction of broadband fan noise levels has gained interest. Advanced manufacturing techniques have also opened new possibilities for the practical implementation of broadband liner concepts. To effectively address these elements, practical acoustic liner design methodologies must provide the capability to efficiently predict the acoustic benefits of novel liner configurations. This paper describes such a methodology to design and evaluate multiple candidate liner configurations using realistic, three dimensional geometries for which minimal source information is available. The development of the design methodology has been guided by a series of studies culminating in the design and flight test of a low drag, broadband inlet liner. The excellent component and system noise benefits obtained in this test demonstrate the effectiveness of the broadband liner design process. They also illustrate the value of the approach in concurrently evaluating multiple liner designs and their application to various locations within the aircraft engine nacelle. Thus, the design methodology may be utilized with increased confidence to investigate novel liner configurations in future design studies.

VariableZ0antenna technology: a new approach for IoT wireless

2014 ◽  
Vol 7 (2) ◽  
pp. 195-203 ◽  
Author(s):  
Richard A. Formato
Keyword(s):  
Internet Of Things ◽  
Degree Of Freedom ◽  
The Internet ◽  
Simple Design ◽  
Wireless Devices ◽  
Decision Space ◽  
New Approach ◽  
Optimization Methodology ◽  
The Internet Of Things

Variable Z0(VZ0) antenna technology is a new design or optimization methodology applicable to any antenna on any platform designed or optimized with any procedure. It should be particularly useful for wireless devices populating the Internet of Things. VZ0expands the design or decision space by adding another degree of freedom invariably leading to better antennas. A simple design example illustrates its effectiveness.

Design and flight test of a Kevlar acoustic liner

1984 ◽  
Vol 21 (7) ◽  
pp. 491-497 ◽  
Author(s):  
Harold C. Lester ◽  
John S. Preisser ◽  
Tony L. Parrott
Keyword(s):  
Flight Test ◽  
Acoustic Liner

scholarly journals Hexafly-INT Experimental Flight Test Vehicle (EFTV) Aero-Thermal Design

2017 ◽  
Author(s):  
Roberto Scigliano ◽  
Giuseppe Pezzella ◽  
Sara Di Benedetto ◽  
Marco Marini ◽  
Johan Steelant
Keyword(s):  
High Speed ◽  
Thermal Protection ◽  
Flight Test ◽  
Thermal Design ◽  
Test Vehicle ◽  
Aerodynamic Efficiency ◽  
Main Driver ◽  
Readiness Level ◽  
Manufacturing Assembly ◽  
Internal Volume

Over the last years, innovative concepts of civil high-speed transportation vehicles were proposed. In this framework, the Hexafly-INT project intends to test in free-flight conditions an innovative gliding vehicle with several breakthrough technologies on-board. This approach will help to gradually increase the readiness level of a consistent number of technologies suitable for hypervelocity flying systems. The vehicle design, manufacturing, assembly and verification is the main driver and challenge in this project. The prime objectives of this free-flying high-speed cruise vehicle shall aim at a conceptual design demonstrating a high aerodynamic efficiency in combination with high internal volume; controlled level flight at a cruise Mach number of 7 to 8;an optimal use of advanced high-temperature materials and structures. Present research describes the aero-thermal design process of the Experimental Flight Test Vehicle, namely EFTV. The glider aeroshape design makes maximum use of databases, expertise, technologies and materials elaborated in previously European community co-funded projects LAPCAT I & II [1][2], ATLLAS I & II [3][4] and HEXAFLY [5]. The paper presents results for both CFD and Finite Element aero-thermal analysis, performed in the most critical phase of the experimental flight leading to the selection of materials for the different components and to a suitable Thermal Protection System.

scholarly journals Design and Development of Hybrid-Electric Propulsion Model for Aeronautics

2019 ◽  
Vol 304 ◽  
pp. 03012
Author(s):  
Giuseppe Di Lorenzo ◽  
Emma Frosina ◽  
Luigi De Petrillo ◽  
Davide Lauria ◽  
Adolfo Senatore ◽  
...  
Keyword(s):  
Electric Propulsion ◽  
Combustion Engine ◽  
Fuel Efficiency ◽  
Electric Energy ◽  
General Aviation ◽  
Electric Energy Storage ◽  
Commercial Code ◽  
Readiness Level ◽  
Hybrid Electric ◽  
Discharge Profile

Nowadays, worldwide environmental issue, associated to reduction of pollutant and greenhouse emissions are gaining considerable attention. Aviation sector contribution to the whole CO2 released accounts to around 2%, but it is expected to grow in the next future due to increase of demand. Probably, combustion engine design and fuel efficiency have already reached their optimum technology level and only a breakthrough as hybrid-electric propulsion could be able to satisfy the new international more demanding requirements. However, an improvement of the technology readiness level of hybrid-electric propulsion is strongly necessary and many operational and safety challenges should be addressed. In the work here reported, a hybrid-electric model was designed and developed for general aviation aircrafts, by means of the Mathworks® Matlab – Simulink 1D/0D simulation environment. Both thermal and electric energy storage units, transmission systems and power management devices were considered and the overall performances were evaluated during cruise phase and a conventional training mission, characterized by several run(lap) “touch-and-go”. Furthermore, an innovative mathematical methodology was implemented for battery pack discharge profile interpolation. Finally, reliability and accuracy of the new proposed model were evaluated through comparison with the commercial code Simcenter AMESim® software and an average bias only equal to 5% was achieved.

scholarly journals IMPLEMENTATION OF LONGITUDINAL WELDING STRESSES INTO STRUCTURAL CALCULATION OF STEEL STRUCTURES

2015 ◽  
Vol 22 (1) ◽  
pp. 47-55 ◽  
Author(s):  
Hartmut Pasternak ◽  
Gabriel Kubieniec
Keyword(s):  
Numerical Simulation ◽  
Residual Stress ◽  
Cross Sections ◽  
High Strength Steels ◽  
Evaluation Process ◽  
Steel Structures ◽  
High Strength ◽  
Experimental Models ◽  
Structural Calculation ◽  
The Difference

During welding of typical steel cross sections, like T or I- Profiles e.g., residual stress occurs and need to be considered during the design process. With knowledge of the stress state after welding, farther calculation with different models are carried out. The systematic study will show three steps of the Okerblom's model to consider in the evaluation process of the welding stresses. The results of the numerical simulation and experimental models are show and compared. With that, the difference between the buckling curve from EN 1993-1-1 (2006) and the study are shown for steel S235 and S460. Especially for the high strength steels, the nowadays design conditions are very conservative and further investigation is needed and recommended.

The design and flight test of an engine inlet bulk acoustic liner

1983 ◽  
Author(s):  
H. LESTER ◽  
J. PREISSER ◽  
T. PARROTT
Keyword(s):  
Flight Test ◽  
Acoustic Liner

Liner development at low technology readiness level utilizing the advanced noise control fan

2021 ◽  
pp. 1475472X2110238
Author(s):  
Daniel L Sutliff
Keyword(s):  
Noise Control ◽  
Risk Mitigation ◽  
Technology Readiness ◽  
Test Bed ◽  
Test And Evaluation ◽  
Ducted Fan ◽  
Technology Readiness Level ◽  
Acoustic Liner ◽  
Readiness Level ◽  
The University

The Advanced Noise Control Fan (ANCF) was utilized in the design, test, and evaluation for technical risk mitigation for many of the innovative ducted acoustic liner technologies developed by NASA over the past 20 years. The ANCF is a low-speed ducted fan test bed for measuring and understanding fan-generated aeroacoustics, duct propagation, and radiation to the farfield. It is considered a low Technology Readiness Level testbed. The international aeroacoustics research community employed the ANCF to facilitate advancement of liner concepts, liner measurement technologies, and for liner code validation. From 1994 to 2016, it was located in the NASA Glenn Research Center’s Applied Aero Propulsion Laboratory. In 2016 the ANCF was transferred to the University of Notre Dame where it is expected to continue to positively impact research in the liner area. This paper summarizes the capabilities and contributions of the ANCF to the field of liner development by documenting its history.

Design and Analysis of an Innovative Modular Extendable Manipulator

2014 ◽  
Author(s):  
Hak Yi ◽  
Reza Langari
Keyword(s):  
Design Strategy ◽  
Robotic Manipulator ◽  
Degree Of Freedom ◽  
Jet Propulsion ◽  
Reachable Workspace ◽  
Analysis Scheme ◽  
Constrained Environments ◽  
Simulation Results ◽  
Jet Propulsion Laboratory ◽  
Optimization Methodology

This study present a design and analysis scheme for the extend-able modular robotic manipulator with multi Degree of Freedom links that is capable of elongating by 15% of its nominal length. The intent is to facilitate the movement of the proposed robotic manipulator in constraint environments, such as rubble piles. In this context, the total number of links decided by optimization methodology can be a useful distinction in practice. In order to identify the benefits of the proposed design strategy, the reachable workspace of the proposed manipulator is compared with that of the Jet Propulsion Laboratory (JPL) serpentine robot. The simulation results show that the proposed manipulator has a relatively efficient reachable workspace to deal with a variety of constrained directions, needed in constrained environments. Also, the singularity of the designed manipulator is investigated.

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