|
|
 |
 |
|
|
|
Selected Navigations:
Author >
[x]
|
Sort results by:
|
|
|
There are a total of 29 record(s) matching your query.
Sorted by: Date Added To NTRS in Descending order
|
Ultra-high bypass research
Author(s): Miller, Christopher J.; Dittmar, James H.; Jeracki, Robert J.
Abstract: An overview of the ultra-high bypass research at the NASA Lewis Research Center is presented. Over the past decade, the program was focused on unducted rotors and precipitated several development efforts in industry. In this ...
NASA Center: Glenn Research Center
Publication Year: 1991
Added to NTRS: 2008-05-31
Accession Number: 91N20117; Document ID: 19910010804
Noise trends of a 0.5 m (20 in.) diameter supersonic throughflow fan as measured in an unmodified compressor aerodynamic test facility
Author(s): Dittmar, James H.; Hall, David G.; Moore, Royce D.
Abstract: The tone noise levels of a supersonic throughflow fan were measured at subsonic and supersonic axial duct Mach numbers. The noise in the inlet plenum showed no blade passing and harmonic tones at subsonic or supersonic axial ...
NASA Center: Glenn Research Center
Publication Year: 1993
Added to NTRS: 2007-12-14
Accession Number: 93X10800; Document ID: 19930076155; Report Number: E-7618, NAS 1.15:106041, NASA-TM-106041
An evaluation of some alternative approaches for reducing fan tone noise
Author(s): Dittmar, James H.; Woodward, Richard P.
Abstract: The potential of two alternative approaches for reducing fan ton noise was investigated in this study. One of these approaches increases the number of rotor blades to shift the tone noise to higher frequencies that are not ...
NASA Center: Glenn Research Center
Publication Year: 1992
Added to NTRS: 2007-03-30
Accession Number: 92N18282; Document ID: 19920009040; Report Number: E-6730, NAS 1.15:105356, NASA-TM-105356
An estimate of the noise shielding on the fuselage resulting from installing a short duct around an advanced propeller
Author(s): Dittmar, James H.
Abstract: A simple barrier shielding model was used to estimate the amount of noise shielding on the fuselage that could result from installing a short duct around a wing-mounted advanced propeller. With the propeller located ...
NASA Center: Glenn Research Center
Publication Year: 1988
Added to NTRS: 2005-10-13
Accession Number: 88N18379; Document ID: 19880008995; Report Number: E-3891, NAS 1.15:100262, NASA-TM-100262
Noise reduction for model counterrotation propeller at cruise by reducing aft-propeller diameter
Author(s): Dittmar, James H.; Stang, David B.
Abstract: The forward propeller of a model counterrotation propeller was tested with its original aft propeller and with a reduced diameter aft propeller. Noise reductions with the reduced diameter aft propeller were measured at ...
NASA Center: Glenn Research Center
Publication Year: 1987
Added to NTRS: 2005-10-13
Accession Number: 87N19057; Document ID: 19870009624; Report Number: E-3378, NAS 1.15:88936, NASA-TM-88936
Cruise noise of the 2/9th scale model of the Large-scale Advanced Propfan (LAP) propeller, SR-7A
Author(s): Dittmar, James H.; Stang, David B.
Abstract: Noise data on the Large-scale Advanced Propfan (LAP) propeller model SR-7A were taken in the NASA Lewis Research Center 8 x 6 foot Wind Tunnel. The maximum blade passing tone noise first rises with increasing helical tip ...
NASA Center: Glenn Research Center
Publication Year: 1987
Added to NTRS: 2005-10-13
Accession Number: 87N28398; Document ID: 19870018965; Report Number: E-3746, NAS 1.15:100175, NASA-TM-100175
The effect of front-to-rear propeller spacing on the interaction noise of a model counterrotation propeller at cruise conditions
Author(s): Dittmar, James H.
Abstract: The effect of front-to-rear propeller spacing on the interaction noise of a counterrotation propeller model was measured at cruise conditions. The data taken at an axial Mach number of 0.80 behaved as expected: interaction ...
NASA Center: Glenn Research Center
Publication Year: 1987
Added to NTRS: 2005-10-13
Accession Number: 87N28396; Document ID: 19870018963; Report Number: E-3667, NAS 1.15:100121, NASA-TM-100121
Comparison of propeller cruise noise data taken in the NASA Lewis 8- by 6-foot wind tunnel with other tunnel and flight data
Author(s): Dittmar, James H.
Abstract: The noise of advanced high speed propeller models measured in the NASA 8- by 6-foot wind tunnel has been compared with model propeller noise measured in another tunnel and with full-scale propeller noise measured in flight. ...
NASA Center: Glenn Research Center
Publication Year: 1989
Added to NTRS: 2005-08-25
Accession Number: 89N21628; Document ID: 19890012257; Report Number: AIAA PAPER 89-1059, E-4676, NAS 1.15:101976, NASA-TM-101976
Cruise noise measurements of a scale model advanced ducted propulsor
Author(s): Dittmar, James H.; Hughes, Christopher E.; Bock, Lawrence A.; Hall, David G.
Abstract: A scale model Advanced Ducted Propulsor (ADP) was tested in NASA Lewis Research Center's 8- by 6-Foot Wind Tunnel to obtain acoustic data at cruise conditions. The model, designed and manufactured by Pratt & Whitney Division ...
NASA Center: Glenn Research Center
Publication Year: 1993
Added to NTRS: 2005-08-25
Accession Number: 94N15115; Document ID: 19940010642; Report Number: AIAA PAPER 93-4400, E-8042, NAS 1.15:105808, NASA-TM-105808
Predicted and measured boundary layer refraction for advanced turboprop propeller noise
Author(s): Dittmar, James H.; Krejsa, Eugene A.
Abstract: Currently, boundary layer refraction presents a limitation to the measurement of forward arc propeller noise measured on an acoustic plate in the NASA Lewis 8- by 6-Foot Supersonic Wind Tunnel. The use of a validated ...
NASA Center: Glenn Research Center
Publication Year: 1990
Added to NTRS: 2005-08-25
Accession Number: 90N17413; Document ID: 19900008097; Report Number: E-5081, NAS 1.15:102365, NASA-TM-102365
|
|
|
|
|
