Ring wing tension vehicle Patent

Design of ring wing vehicle of high drag-to-weight ratio to withstand reentry stress into low density atmospher

Comparison of experimental vibration characteristics obtained from a 1/5-scale model and from a full-scale saturn sa-1

Vibrational testing of scale model and full scale Saturn I /SA-1/ launch vehicl

A theoretical investigation of noise reduction through the cylindrical fuselage of a twin-engine, propeller-driven aircraft

Interior noise in the fuselage of a twin-engine, propeller-driven aircraft with two propellers rotating in opposite directions is studied analytically. The fuselage was modeled as a stiffened cylindrical shell with simply supported ends, and the effects of stringers and frames were averaged over the shell surface. An approximate mathematical model of the propeller noise excitation was formulated which includes some of the propeller noise characteristics such as sweeping pressure waves around the sidewalls due to propeller rotation and the localized nature of the excitation with the highest levels near the propeller plane. Results are presented in the form of noise reduction, which is the difference between the levels of external and interior noise. The influence of propeller noise characteristics on the noise reduction was studied. The results indicate that the sweep velocity of the excitation around the fuselage sidewalls is critical to noise reduction

Acoustic fatigue: Overview of activities at NASA Langley

A number of aircraft and spacecraft configurations are being considered for future development. These include high-speed turboprop aircraft, advanced vertical take-off and landing fighter aircraft, and aerospace planes for hypersonic intercontinental cruise or flight to orbit and return. Review of the acoustic environment expected for these vehicles indicates levels high enough that acoustic fatigue must be considered. Unfortunately, the sonic fatique design technology used for current aircraft may not be adequate for these future vehicles. This has resulted in renewed emphasis on acoustic fatigue research at the NASA Langley Research Center. The overall objective of the Langley program is to develop methods and information for design of aerospace vehicles that will resist acoustic fatigue. The program includes definition of the acoustic loads acting on structures due to exhaust jets of boundary layers, and subsequent determination of the stresses within the structure due to these acoustic loads. Material fatigue associated with the high frequency structural stress reversal patterns resulting from acoustic loadings is considered to be an area requiring study, but no activity is currently underway

Interior Noise

The generation and control of flight vehicle interior noise is discussed. Emphasis is placed on the mechanisms of transmission through airborne and structure-borne paths and the control of cabin noise by path modification. Techniques for identifying the relative contributions of the various source-path combinations are also discussed along with methods for the prediction of aircraft interior noise such as those based on the general modal theory and statistical energy analysis

Consideration of some factors affecting low-frequency fuselage noise transmission for propeller aircraft

Possible reasons for disagreement between measured and predicted trends of sidewall noise transmission at low frequency are investigated using simplified analysis methods. An analytical model combining incident plane acoustic waves with an infinite flat panel is used to study the effects of sound incidence angle, plate structural properties, frequency, absorption, and the difference between noise reduction and transmission loss. Analysis shows that these factors have significant effects on noise transmission but they do not account for the differences between measured and predicted trends at low frequencies. An analytical model combining an infinite flat plate with a normally incident acoustic wave having exponentially decaying magnitude along one coordinate is used to study the effect of a localized source distribution such as is associated with propeller noise. Results show that the localization brings the predicted low-frequency trend of noise transmission into better agreement with measured propeller results. This effect is independent of low-frequency stiffness effects that have been previously reported to be associated with boundary conditions

Sources, control, and effects of noise from aircraft propellers and rotors

Source noise predictions are compared with measurements for conventional low-speed propellers, for new high speed propellers (propfans), and for a helicopter. Results from a light aircraft demonstration program are described, indicating that about 5-dB reduction of flyover noise can be obtained without significant performance penalty. Sidewall design studies are described for interior noise control in light general aviation aircraft and in large transports using propfan propulsion. The weight of the added acoustic treatment is estimated and tradeoffs between weight and noise reduction are discussed. A laboratory study of passenger response to combined broadband and tonal propeller like noise is described. Subject discomfort ratings of combined tone broadband noises are compared with ratings of broadband (boundary layer) noise alone, and the relative importance of the propeller tones is examined

Assessment of the toxicological effects of CNT-Ab in mice followed by microwave hyperthermia 14 days post treatment.

Serious side effects and treatment resistance are the main impediments to successful cancer therapy. A variety of nanoparticles have been used for localized, site-specific treatment that prevent or circumvent these impediments. Microwaves alone have been previously used for thermal ablation of various tumors, setting precedence for their successful use in live organisms. In cell culture studies, it has been observed that multiwall carbon nanotubes (MWCNTs) instantly and efficiently absorb microwaves, causing hyperthermia of cells in direct contact with them with unnoticed harm to other cells. It is hypothesized that a treatment can be developed based on a safe microwave heating schedule for the selective ablation of tumor cells in vivo using MWCNT-ab conjugates as a targeting medium and mice as animal models. This was accomplished by conjugating MWCNTs with anti-PSMA antibodies (ab) in order to induce the selective uptake of MWCNTs by PC3 cells, known to significantly over-express PSMA antigens in comparison to non-cancerous cells. This study sought to elucidate any toxicological effects by the characterization of MWCNT-ab distribution, clearance, and toxicology in mice following microwave hyperthermia. This was assessed through clinical chemistry and analyzing gene expression in the brain, liver, and kidney. Results seem to suggest that exposure to MWCNT-Ab cause injury to the liver and kidney in higher doses. Blood serum markers of AST and creatinine were significantly elevated in some of the treatment groups. Similarly, upregulation of IL6, NFkB, PTGS2, and TNF-α in brain, liver and kidney tissues was observed for some of the MWCNT-Ab exposed mice. The results are consistent with our initial assessment that MWCNT-Ab are safe at low doses and display increasing toxicity as the concentration of MWCNTs increase. In conclusion, exposure to MWCNT conjugated antibody and microwave may produce inflammatory response in the brain, liver and kidney of mice

Campus Commons: Lessons from an Outdoor Classroom

The author shares an experience that opened her mind to the transformative nature of her ropes course work with students and reminded her why she does it