Download or read book Active Structural Acoustic Control of Interior Noise on a Raytheon 1900d written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-05-29 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt: An active structural acoustic control system has been demonstrated on a Raytheon Aircraft Company 1900D turboprop airliner. Both single frequency and multi-frequency control of the blade passage frequency and its harmonics was accomplished. The control algorithm was a variant of the popular filtered-x LMS implemented in the principal component domain. The control system consisted of 21 inertial actuators and 32 microphones. The actuators were mounted to the aircraft's ring frames. The microphones were distributed uniformly throughout the interior at head height, both seated and standing. Actuator locations were selected using a combinatorial search optimization algorithm. The control system achieved a 14 dB noise reduction of the blade passage frequency during single frequency tests. Multi-frequency control of the first 1st, 2nd and 3rd harmonics resulted in 10.2 dB, 3.3 dB and 1.6 dB noise reductions respectively. These results fall short of the predictions which were produced by the optimization algorithm (13.5 dB, 8.6 dB and 6.3 dB). The optimization was based on actuator transfer functions taken on the ground and it is postulated that cabin pressurization at flight altitude was a factor in this discrepancy.Palumbo, Dan and Cabell, Ran and Sullivan, Brenda and Cline, JohnLangley Research CenterACTIVE CONTROL; NOISE (SOUND); STRUCTURAL STABILITY; NOISE REDUCTION; OPTIMIZATION; COMBINATORIAL ANALYSIS; TRANSPORT AIRCRAFT; ALGORITHMS; FLIGHT ALTITUDE; TRANSFER FUNCTIONS; HARMONICS

Download or read book Active Structural Acoustic Control of Interior Noise on a Raytheon 1900D written by and published by . This book was released on 2000 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Active Structural Acoustic Control of Noise Transmission Through Double Panel Systems written by James P. Carneal and published by . This book was released on 1993 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Structural Acoustic Prediction and Interior Noise Control Technology written by and published by DIANE Publishing. This book was released on 2001 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Variational Analysis and Aerospace Engineering written by Giuseppe Buttazzo and published by Springer Science & Business Media. This book was released on 2009-08-21 with total page 527 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Variational Analysis and Aerospace Engineering conference held in Erice, Italy in September 2007 at International School of Mathematics, Guido Stampacchia provided a platform for aerospace engineers and mathematicians to discuss the problems requiring an extensive application of mathematics. This work contains papers presented at the workshop.

Download or read book Smart Structures and Materials written by and published by . This book was released on 2001 with total page 550 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Structural Acoustic Prediction and Interior Noise Control Technology Nasa written by United States. National Aeronautics and Space Administration and published by . This book was released on 2002* with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Langley Research Highlights 1999 Advanced Aerospace Technology Clouds That Help Create the Ozone Hole Capturing Comet Dust written by and published by . This book was released on 2000 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Active Structural Acoustic Control of Broad Band Sound Transmission Through a Panel written by D. K. Peterson and published by . This book was released on 1996 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Experimental and Numerical Analysis of Structural Acousticcontrol Interior Noise Reduction written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2018-09-19 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt: The research results contained in this technical report were performed under the NASA grant entitled "Experimental and Numerical Structural Acoustic Control for Interior Noise Reduction." The report is based essentially on partial progress of the Ph.D. dissertation prepared by Jeffrey S. Bevan under direct guidance of Dr. Chuh Mei. The document presents a finite element formulation and control of sound radiated from cylindrical panels embedded with piezoceramic actuators. The extended MIN6 shallow shell element is fully electrical-structural coupled. A piezoelectric modal actuator participation (PMAP) is defined which indicates the actuator performance to each of the offending modes. Genetic algorithm is also employed to validate the sensor and actuator locations determined by the PMAP criteria. The work was conducted at the Department of Aerospace Engineering, Old Dominion University. Mr. Travis L. Turner, Structural Acoustics Branch, NASA Langley Research Center is the technical monitor.Mei, Chuh and Bevan, Jeffrey S.Langley Research CenterNUMERICAL ANALYSIS; EXPERIMENTATION; NOISE REDUCTION; ACOUSTICS; ACTUATORS; RESEARCH; FINITE ELEMENT METHOD; SHALLOW SHELLS; POSITION (LOCATION); PIEZOELECTRICITY; PIEZOELECTRIC CERAMICS; PANELS; NUMERICAL CONTROL; NOISE (SOUND); CYLINDRICAL BODIES

Download or read book Radiation Modal Expansion for Active Structural Acoustic Control written by Gary P. Gibbs and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Numerical Comparison of Active Acoustic and Structural Noise Control in a Stiffened Doubla Wall Cylinder written by Ferdinand W. Grosveld and published by . This book was released on 1996 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Active Structural Acoustic Control of Double Panel Systems Including Hierarchical Control Approaches written by James P. Carneal and published by . This book was released on 1996* with total page 452 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Future of Air Power in the Aftermath of the Gulf War written by Robert L. Pfaltzgraff and published by DIANE Publishing. This book was released on 1992 with total page 387 pages. Available in PDF, EPUB and Kindle. Book excerpt: This collection of essays reflects the proceedings of a 1991 conference on "The United States Air Force: Aerospace Challenges and Missions in the 1990s," sponsored by the USAF and Tufts University. The 20 contributors comment on the pivotal role of airpower in the war with Iraq and address issues and choices facing the USAF, such as the factors that are reshaping strategies and missions, the future role and structure of airpower as an element of US power projection, and the aerospace industry's views on what the Air Force of the future will set as its acquisition priorities and strategies. The authors agree that aerospace forces will be an essential and formidable tool in US security policies into the next century. The contributors include academics, high-level military leaders, government officials, journalists, and top executives from aerospace and defense contractors.

Download or read book The Turbine Pilot s Flight Manual written by Gregory N. Brown and published by Wiley-Blackwell. This book was released on 2001-10-25 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt: Highly illustrated and clearly written, The Turbine Pilot's Flight Manual is a must have for all pilots. It offers a complete description of turbine aircraft engines and systems including turboprops and jets. Additional chapters on high-speed aerodynamics, multipilot crew co-ordination, wake turbulence and high altitude weather are discussed at length. The book is perfect for not only those involved in pure jet operations; but for those involved in turboprop, multipilot operations, and transition training. It is a key tool for a successful turbine aviation career.

Download or read book Acoustic Absorbers and Diffusers written by Trevor J. Cox and published by CRC Press. This book was released on 2009-01-26 with total page 495 pages. Available in PDF, EPUB and Kindle. Book excerpt: Absorbers and diffusers are two of the main design tools for altering the acoustic conditions of rooms, semi-enclosed spaces and the outdoor environment. Their correct use is important for delivering high quality acoustics. Unique and authoritative, this book decribes how to effectively measure, model, design and apply diffusers and absorbers. It is a resource for new and experienced acousticians, seeking an understanding of the evolution, characteristics and application of modern diffusers. Absorption is a more established technology and so the book blends traditional designs with modern developments. The book covers practical and theoretical aspects of absorbers and diffusers and is well illustrated with examples of installations and case studies. This new edition brings Acoustic Absorbers and Diffusers up-to-date with current research, practice and standards. New developments in measurement, materials, theory and practice since the first edition (published in 2004) are included. The sections on absorbers are extended to include more about noise control.

Download or read book Economic Security Neglected Dimension of National Security written by National Defense University (U S ) and published by Government Printing Office. This book was released on 2011-12-27 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt: On August 24-25, 2010, the National Defense University held a conference titled “Economic Security: Neglected Dimension of National Security?” to explore the economic element of national power. This special collection of selected papers from the conference represents the view of several keynote speakers and participants in six panel discussions. It explores the complexity surrounding this subject and examines the major elements that, interacting as a system, define the economic component of national security.