NASA Hybrid Wing Aircraft Aeroacoustic Test Documentation Report

This report summarizes results of the Hybrid Wing Body (HWB) N2A-EXTE model aeroacoustic test. The N2A-EXTE model was tested in the NASA Langley 14- by 22-Foot Subsonic Tunnel (14x22 Tunnel) from September 12, 2012 until January 28, 2013 and was designated as test T598. This document contains the following main sections: Section 1 - Introduction, Section 2 - Main Personnel, Section 3 - Test Equipment, Section 4 - Data Acquisition Systems, Section 5 - Instrumentation and Calibration, Section 6 - Test Matrix, Section 7 - Data Processing, and Section 8 - Summary. Due to the amount of material to be documented, this HWB test documentation report does not cover analysis of acquired data, which is to be presented separately by the principal investigators. Also, no attempt was made to include preliminary risk reduction tests (such as Broadband Engine Noise Simulator and Compact Jet Engine Simulator characterization tests, shielding measurement technique studies, and speaker calibration method studies), which were performed in support of this HWB test. Separate reports containing these preliminary tests are referenced where applicable

Hybrid Wing Body Aircraft Acoustic Test Preparations and Facility Upgrades

NASA is investigating the potential of acoustic shielding as a means to reduce the noise footprint at airport communities. A subsonic transport aircraft and Langley's 14- by 22-foot Subsonic Wind Tunnel were chosen to test the proposed "low noise" technology. The present experiment studies the basic components of propulsion-airframe shielding in a representative flow regime. To this end, a 5.8-percent scale hybrid wing body model was built with dual state-of-the-art engine noise simulators. The results will provide benchmark shielding data and key hybrid wing body aircraft noise data. The test matrix for the experiment contains both aerodynamic and acoustic test configurations, broadband turbomachinery and hot jet engine noise simulators, and various airframe configurations which include landing gear, cruise and drooped wing leading edges, trailing edge elevons and vertical tail options. To aid in this study, two major facility upgrades have occurred. First, a propane delivery system has been installed to provide the acoustic characteristics with realistic temperature conditions for a hot gas engine; and second, a traversing microphone array and side towers have been added to gain full spectral and directivity noise characteristics

Biogenesis of medium-chain-length polyhydroxyalkanoates

26 p.-3 fig.-2 tab.Medium-chain-length polyhydroxyalkanoates (mcl-PHA) are biotechnologically useful natural products found in many bacteria. This biopolymer functions as a carbon and energy storage reservoir in cells but has physical and mechanical properties that make it a promising bioplastic with applications ranging from adhesives to medical implants. Therefore, there is much interest in understanding the biology of mcl-PHA synthesis and metabolism. Increased knowledge of PHA biology serves as a foundation for the bioengineering of PHA and its eventual use as a biologically derived product. This chapter covers the state of knowledge on mcl-PHA, including its synthesis and its central role in cellular metabolism. Moreover, this chapter discusses methods for bioengineering mcl-PHA production in bacteria as well as synthetic biology methods for its study and production in the natural mcl-PHA producer, Pseudomonas putida.Research on polymer biotechnology in the laboratory of M. Auxiliadora Prieto is supported by funding from the European Union’s Horizon 2020 research and innovation program under grant agreements number 633962 and 679050. We also acknowledge support from the Community of Madrid (P2013/MIT2807) and the Spanish Ministry of Economy (BIO201344878R, BIO2014-61515-EXP).Peer reviewedPostprin