Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781722313289
Category :
Languages : en
Pages : 86
Book Description
A computational jet noise study of a short conical plug-nozzle (CPN) is presented. The CPN has an exit diameter of 45 mm and the geometrical configuration closely approximates that of an ideal contoured plug-nozzle having shockless flow at pressure ratio xi(sub d) = 3.62. The gasdynamics of the jet flows have been predicted using the CFD code, NPARC with k-epsilon turbulence model; these data are then used for noise computations based on the modified GE/MGB code. The study covers a range of pressure ratio, 2.0 less than or equal to xi less than or equal to 5.0. The agreement of the computational results with the available experimental data is favorable. The results indicate consistent noise reduction effectiveness of the CPN as compared to equivalent convergent, convergent-divergent and ideal contoured plug nozzles at all pressure ratios. At design pressure ratio, codes predict noise levels within 4.0 dB of the measurements; and at off-design pressure ratios, in general, within 5.0 dB except at very high frequencies when deviations up to 10 dB are noted. The shock formation mechanism in the CPN jet is noted to be basically different from those in the convergent and CD nozzle jets. Das, Indu S. and Khavaran, Abbas and Das, A. P. Glenn Research Center...
Computational Noise Study of a Supersonic Short Conical Plug-Nozzle Jet
Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781722313289
Category :
Languages : en
Pages : 86
Book Description
A computational jet noise study of a short conical plug-nozzle (CPN) is presented. The CPN has an exit diameter of 45 mm and the geometrical configuration closely approximates that of an ideal contoured plug-nozzle having shockless flow at pressure ratio xi(sub d) = 3.62. The gasdynamics of the jet flows have been predicted using the CFD code, NPARC with k-epsilon turbulence model; these data are then used for noise computations based on the modified GE/MGB code. The study covers a range of pressure ratio, 2.0 less than or equal to xi less than or equal to 5.0. The agreement of the computational results with the available experimental data is favorable. The results indicate consistent noise reduction effectiveness of the CPN as compared to equivalent convergent, convergent-divergent and ideal contoured plug nozzles at all pressure ratios. At design pressure ratio, codes predict noise levels within 4.0 dB of the measurements; and at off-design pressure ratios, in general, within 5.0 dB except at very high frequencies when deviations up to 10 dB are noted. The shock formation mechanism in the CPN jet is noted to be basically different from those in the convergent and CD nozzle jets. Das, Indu S. and Khavaran, Abbas and Das, A. P. Glenn Research Center...
Publisher: Createspace Independent Publishing Platform
ISBN: 9781722313289
Category :
Languages : en
Pages : 86
Book Description
A computational jet noise study of a short conical plug-nozzle (CPN) is presented. The CPN has an exit diameter of 45 mm and the geometrical configuration closely approximates that of an ideal contoured plug-nozzle having shockless flow at pressure ratio xi(sub d) = 3.62. The gasdynamics of the jet flows have been predicted using the CFD code, NPARC with k-epsilon turbulence model; these data are then used for noise computations based on the modified GE/MGB code. The study covers a range of pressure ratio, 2.0 less than or equal to xi less than or equal to 5.0. The agreement of the computational results with the available experimental data is favorable. The results indicate consistent noise reduction effectiveness of the CPN as compared to equivalent convergent, convergent-divergent and ideal contoured plug nozzles at all pressure ratios. At design pressure ratio, codes predict noise levels within 4.0 dB of the measurements; and at off-design pressure ratios, in general, within 5.0 dB except at very high frequencies when deviations up to 10 dB are noted. The shock formation mechanism in the CPN jet is noted to be basically different from those in the convergent and CD nozzle jets. Das, Indu S. and Khavaran, Abbas and Das, A. P. Glenn Research Center...
Computational Noise Study of a Supersonic Short Conical Plug-nozzle Jet
Author: Indu S. Das
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
Computational Study of a Contoured Plug-nozzle as a Supersonic Jet Noise Suppressor
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 84
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 84
Book Description
Computational Study of a Contoured Plug-Nozzle As a Supersonic Jet Noise Suppressor
Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781722313494
Category :
Languages : en
Pages : 84
Book Description
The report summarizes a computational jet noise study of an ideal contoured plug-nozzle (CPN). The gasdynamics of the jet flows have been predicted using the CFD code, NPARC with k-epsilon turbulence model; these data are then used as inputs to perform the noise computations based on the modified version of General Electric MGB code. The study covers a range of operating pressure ratio, 2.0 less than xi less than 5.0 (shockless flow at design pressure ratio, xi(d) = 3.62). The agreement of the computational aeroacoustics results with the available experimental data may be considered to be favorable. The computational results indicate consistent noise reduction effectiveness of the CPN at all operating pressure ratios. At the design pressure ratio (shockless), the codes predict overall sound pressure levels within +3.O dB of the experimental data. But at the off-design pressure ratios (flaws with shocks), the agreement is rather mixed. The theory overpredicts the OASPL's at all pressure ratios except at lower angles to the jet axis in overexpanded mode (xi less than xi(d)), the deviations being within 4.5 dB. The mechanism of shock formations in the CPN jet flows is noted to be basically different from those in the convergent-divergent nozzle jet flows. Khavaran, A. and Das, A. P. and Das, I.S. Glenn Research Center...
Publisher: Createspace Independent Publishing Platform
ISBN: 9781722313494
Category :
Languages : en
Pages : 84
Book Description
The report summarizes a computational jet noise study of an ideal contoured plug-nozzle (CPN). The gasdynamics of the jet flows have been predicted using the CFD code, NPARC with k-epsilon turbulence model; these data are then used as inputs to perform the noise computations based on the modified version of General Electric MGB code. The study covers a range of operating pressure ratio, 2.0 less than xi less than 5.0 (shockless flow at design pressure ratio, xi(d) = 3.62). The agreement of the computational aeroacoustics results with the available experimental data may be considered to be favorable. The computational results indicate consistent noise reduction effectiveness of the CPN at all operating pressure ratios. At the design pressure ratio (shockless), the codes predict overall sound pressure levels within +3.O dB of the experimental data. But at the off-design pressure ratios (flaws with shocks), the agreement is rather mixed. The theory overpredicts the OASPL's at all pressure ratios except at lower angles to the jet axis in overexpanded mode (xi less than xi(d)), the deviations being within 4.5 dB. The mechanism of shock formations in the CPN jet flows is noted to be basically different from those in the convergent-divergent nozzle jet flows. Khavaran, A. and Das, A. P. and Das, I.S. Glenn Research Center...
The Generation and Radiation of Supersonic Jet Noise
Author: Lockheed-Georgia Company
Publisher:
ISBN:
Category : Jet planes
Languages : en
Pages : 270
Book Description
Publisher:
ISBN:
Category : Jet planes
Languages : en
Pages : 270
Book Description
Aeroacoustics of Supersonic Jet Flows from Contoured and Solid/porous Conical Plug-nozzles
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 192
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 192
Book Description
Aeroacoustics of Contoured and Solid Porous Conical Plug Nozzle Supersonic Jet Flows
Author:
Publisher:
ISBN:
Category : Jets
Languages : en
Pages :
Book Description
Publisher:
ISBN:
Category : Jets
Languages : en
Pages :
Book Description
Experimental Investigation of a 10 Deg Conical Turbojet Plug Nozzle with Translating Primary and Secondary Shrouds at Mach Numbers from 0 to 2.0
Author: Donald L. Bresnahan
Publisher:
ISBN:
Category :
Languages : en
Pages : 46
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 46
Book Description
Monthly Catalog of United States Government Publications
Author:
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 1154
Book Description
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 1154
Book Description
Initial Results of a Porous Plug Nozzle for Supersonic Jet Noise Suppression
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 26
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 26
Book Description