Unsteady Velocity Measurements in the Nasa Research Low Speed Axial Compressor PDF Download
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Author: Jan Lepicovsky
Publisher: BiblioGov
ISBN: 9781289237158
Category :
Languages : en
Pages : 118
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Book Description
The report is a collection of experimental unsteady data acquired in the first stage of the NASA Low Speed Axial Compressor in configuration with smooth (solid) wall treatment over the first rotor. The aim of the report is to present a reliable experimental data base that can be used for analysis of the compressor flow behavior, and hopefully help with further improvements of compressor CFD codes. All data analysis is strictly restricted to verification of reliability of the experimental data reported. The report is divided into six main sections. First two sections cover the low speed axial compressor, the basic instrumentation, and the in-house developed methodology of unsteady velocity measurements using a thermo-anemometric split-fiber probe. The next two sections contain experimental data presented as averaged radial distributions for three compressor operation conditions, including the distribution of the total temperature rise over the first rotor, and ensemble averages of unsteady flow data based on a rotor blade passage period. Ensemble averages based on the rotor revolution period, and spectral analysis of unsteady flow parameters are presented in the last two sections. The report is completed with two appendices where performance and dynamic response of thermo-anemometric probes is discussed.
Author: Jan Lepicovsky
Publisher: BiblioGov
ISBN: 9781289237158
Category :
Languages : en
Pages : 118
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Book Description
The report is a collection of experimental unsteady data acquired in the first stage of the NASA Low Speed Axial Compressor in configuration with smooth (solid) wall treatment over the first rotor. The aim of the report is to present a reliable experimental data base that can be used for analysis of the compressor flow behavior, and hopefully help with further improvements of compressor CFD codes. All data analysis is strictly restricted to verification of reliability of the experimental data reported. The report is divided into six main sections. First two sections cover the low speed axial compressor, the basic instrumentation, and the in-house developed methodology of unsteady velocity measurements using a thermo-anemometric split-fiber probe. The next two sections contain experimental data presented as averaged radial distributions for three compressor operation conditions, including the distribution of the total temperature rise over the first rotor, and ensemble averages of unsteady flow data based on a rotor blade passage period. Ensemble averages based on the rotor revolution period, and spectral analysis of unsteady flow parameters are presented in the last two sections. The report is completed with two appendices where performance and dynamic response of thermo-anemometric probes is discussed.
Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781721584000
Category :
Languages : en
Pages : 30
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Book Description
A split-fiber probe was used to acquire unsteady data in a research compressor. The probe has two thin films deposited on a quartz cylinder 200 microns in diameter. A split-fiber probe allows simultaneous measurement of velocity magnitude and direction in a plane that is perpendicular to the sensing cylinder, because it has its circumference divided into two independent parts. Local heat transfer considerations indicated that the probe direction characteristic is linear in the range of flow incidence angles of +/- 35. Calibration tests confirmed this assumption. Of course, the velocity characteristic is nonlinear as is typical in thermal anemometry. The probe was used extensively in the NASA Glenn Research Center (GRC) low-speed, multistage axial compressor, and worked reliably during a test program of several months duration. The velocity and direction characteristics of the probe showed only minute changes during the entire test program. An algorithm was developed to decompose the probe signals into velocity magnitude and velocity direction. The averaged unsteady data were compared with data acquired by pneumatic probes. An overall excellent agreement between the averaged data acquired by a split-fiber probe and a pneumatic probe boosts confidence in the reliability of the unsteady content of the split-fiber probe data. To investigate the features of unsteady data, two methods were used: ensemble averaging and frequency analysis. The velocity distribution in a rotor blade passage was retrieved using the ensemble averaging method. Frequencies of excitation forces that may contribute to high cycle fatigue problems were identified by applying a fast Fourier transform to the absolute velocity data. Lepicovsky, Jan Glenn Research Center NASA/CR-2003-212489, NAS 1.26:212489, E-14034, FEDSM2003-45607
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Publisher:
ISBN:
Category :
Languages : en
Pages : 18
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Author: Charles A. Wasserbauer
Publisher:
ISBN:
Category : Aerodynamics
Languages : en
Pages : 24
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Book Description
Author: Michael D. Hathaway
Publisher:
ISBN:
Category : Compressors
Languages : en
Pages : 304
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Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781721650446
Category :
Languages : en
Pages : 32
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Book Description
A split-fiber probe was used to acquire unsteady data in a research compressor. A calibration method was devised for a split-fiber probe, and a new algorithm was developed to decompose split-fiber probe signals into velocity magnitude and direction. The algorithm is based on the minimum value of a merit function that is built over the entire range of flow velocities for which the probe was calibrated. The split-fiber probe performance and signal decomposition was first verified in a free-jet facility by comparing the data from three thermo-anemometric probes, namely a single-wire, a single-fiber, and the split-fiber probe. All three probes performed extremely well as far as the velocity magnitude was concerned. However, there are differences in the peak values of measured velocity unsteadiness in the jet shear layer. The single-wire probe indicates the highest unsteadiness level, followed closely by the split-fiber probe. The single-fiber probe indicates a noticeably lower level of velocity unsteadiness. Experiments in the NASA Low Speed Axial Compressor facility revealed similar results. The mean velocities agreed well, and differences in the velocity unsteadiness are similar to the case of a free jet. A reason for these discrepancies is in the different frequency response characteristics of probes used. It follows that the single-fiber probe has the slowest frequency response. In summary, the split-fiber probe worked reliably during the entire program. The acquired data averaged in time followed closely data acquired by conventional pneumatic probes. Lepicovsky, Jan Glenn Research Center NASA/CR-2004-213065, GT-2004-53954, E-14531
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Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 488
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Book Description
Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
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ISBN:
Category : Fluid dynamics
Languages : en
Pages : 776
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Author: Getu Hailu
Publisher: BoD – Books on Demand
ISBN: 1789840252
Category : Technology & Engineering
Languages : en
Pages : 118
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Book Description
Rotating machinery or turbomachinery is a machine with a rotating component that transfers energy to a fluid or vice versa. Rotating machines are one of the most widely used machines. They are used in everyday life, at least once a day. We find a turbomachine (fan) in a hair dryer and in a computer. We find a turbomachine (pump) in a refrigerator. Other commonly used household machines are clothes washers and dish washers. These machines need to drain the dirty water and replace with clean water. To do so an important component of these machines is a pump that is used to remove the dirty water. A water pump (hydrodynamic pump) is also essential to our car?s operation by maintaining an optimum operating temperature of the engine. The pump ensures that the coolant keeps circulating through the engine block, hoses and radiator, and maintains an optimum operating temperature. Turbomachines are also key machines used in power generation, fluid transportation, the processing industry and energy conversion. This book presents recent developments in improving the aero-thermal performance and the efficiencies of rotating machines.
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ISBN:
Category : Aeronautics
Languages : en
Pages : 538
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