LF336 lift fan modification and acoustic test program

Investigating lift fan noise reduction by configuration modifications in LF336/

NASA/GE quiet engine C acoustic test results

The acoustic investigation and evaluation of the C propulsion turbofan engine are discussed. The engine was built as a part of the Quiet Engine Program. The objectives of the program are as follows: (1) to determine the noise levels produced turbofan bypass engines, (2) to demonstrate the technology and innovations which will reduce the production and radiation of noise in turbofan engines, and (3) to acquire experimental acoustic and aerodynamic data for high bypass turbofan engines to provide a better understanding of noise production mechanisms. The goals of the program called for a turbofan engine 15 to 20 PNdB quieter than currently available engines in the same thrust class

Single stage, low noise advanced technology fan. Volume 3: Acoustic design

The acoustic design for a half-scale fan vehicle, which would have application on an advanced transport aircraft, is described. The single stage advanced technology fan was designed to a pressure ratio of 1.8 at a tip speed of 503 m/sec (1,650 ft/sec). The two basic approaches taken in the acoustic design were: (1) minimization of noise at the source, and (2) suppression of the generated noise in the inlet and bypass exhaust duct. Suppression of the generated noise is accomplished in the inlet through use of the hybrid concept (wall acoustic treatment plus airflow acceleration suppression) and in the exhaust duct with extensive acoustic treatment including a splitter. The goal of the design was attainment of twenty effective perceived noise decibels (20 EPNdB) below current Federal Air Regulation noise standards for a full-scale fan at the takeoff, cutback, and approach conditions. Predicted unsuppressed and suppressed fore and aft maximum perceived noise levels indicate that the cutback condition is the most critical with respect to the goal, which is probably unattainable for that condition. This is also true for aft radiated noise in the approach condition

Acoustic and aerodynamic testing of a scale model variable pitch fan

A fully reversible pitch scale model fan with variable pitch rotor blades was tested to determine its aerodynamic and acoustic characteristics. The single-stage fan has a design tip speed of 1160 ft/sec (353.568 m/sec) at a bypass pressure ratio of 1.5. Three operating lines were investigated. Test results show that the blade pitch for minimum noise also resulted in the highest efficiency for all three operating lines at all thrust levels. The minimum perceived noise on a 200-ft (60.96 m) sideline was obtained with the nominal nozzle. At 44% of takeoff thrust, the PNL reduction between blade pitch and minimum noise blade pitch is 1.8 PNdB for the nominal nozzle and decreases with increasing thrust. The small nozzle (6% undersized) has the highest efficiency at all part thrust conditions for the minimum noise blade pitch setting; although, the noise is about 1.0 PNdB higher for the small nozzle at the minimum noise blade pitch position

The Arc of Liberalism and the Career of Harrison “Pete” Williams

The following address was delivered by Michael Kazin of Georgetown University at the opening of the spring 2009 exhibit, "Crossroads: Senator Harrison A. Williams Jr. and Great Society Liberalism, 1959-1981," at Rutgers –New Brunswick’s Alexander Library, January 27, 2009. The exhibition, which runs from January until August 1, 2009, commemorates the completion of a three-year effort to organize the papers of U.S. Senator Harrison Williams, Jr. of New Jersey. These papers are held in Rutgers University Libraries’ Special Collections and University Archives

An evaluation of a wheel speed change-gyro-compass utilizing a single-degree-of-freedom gyroscope

Massachusetts Institute of Technology. Dept. of Aeronautics and Astronautics. Thesis. 1967. M.S.MICROFICHE COPY ALSO AVAILABLE IN AERO LIBRARY.Includes bibliographical references.by Stuart C. Kazin.M.S

Why Doesn\u27t Worcester Vote?

This research presents findings from a study of voter turnout and registration in Worcester, Massachusetts and takes steps to examine possible reasons why turnout has been consistently low in municipal elections. Specifically, it assesses educational attainment, income, race and ethnicity, and types and function of municipal government as reasons for the minimal turnout. Drawing on literature, case studies throughout the United States, and census and city clerk data, this paper will discuss reasons for voters’ lack of involvement, a comparison of seven municipalities throughout Massachusetts, and recommendations for creating a more civically engaged community in Worcester

Acoustic testing of a 1.5 pressure ratio, low tip speed fan (QEP fan B scale model)

A scale model (0.484 scale factor) of a single stage fan designed for a 1.5 pressure ratio and 1160 ft/sec tip speed was tested to determine its noise characteristics. The fan had 26 blades and 60 outlet guide vanes, with vanes spaced two rotor blade aerodynamic chords from the blades. The effects of speed, exhaust nozzle area and fan frame acoustic treatment on the scale model's noise characteristics were investigated