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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 127 records · Page 7
All sourcesNASA NTRSDOE OSTI
NASA NTRS1990

Adaptation of electronically scanned pressure measurement technology at Langley Research Center

The use of pressure-measurement devices based on electronic scanning in wind-tunnel and other settings with harsh conditions is discussed in terms of adaptations required to protect the integrity of the devices and output data. The applications considered include thermal extremes, long cable lengths, very low pressure, high-line pressure, and variable-reference calibrations. Some of the adaptation techniques are thermal enclosures, remote power supplies, low-pressure standards, and biasing regulators.

Mitchell, Michael↗
NASA NTRS1978

Correlation of combustor acoustic power levels inferred from internal fluctuating pressure measurements

Combustion chamber acoustic power levels inferred from internal fluctuating pressure measurements are correlated with operating conditions and chamber geometries over a wide range. The variables include considerations of chamber design (can, annular, and reverse-flow annular) and size, number of fuel nozzles, burner staging and fuel split, airflow and heat release rates, and chamber inlet pressure and temperature levels. The correlated data include those obtained with combustion component development rigs as well as engines.

Vonglahn, U. H.↗
NASA NTRS1978

Correlation of combustor acoustic power levels inferred from internal fluctuating pressure measurements

Combustion chamber acoustic power levels inferred from internal fluctuating pressure measurements are correlated with operating conditions and chamber geometries over a wide range. The variables include considerations of chamber design (can, annular, and reverse-flow annular) and size, number of fuel nozzles, burner staging and fuel split, airflow and heat release rates, and chamber inlet pressure and temperature levels. The correlated data include those obtained with combustion component development rigs as well as engines.

Von Glahn, U. H.↗
NASA NTRS2004

Determination of Extrapolation Distance with Measured Pressure Signatures from Two Low-Boom Models

A study to determine a limiting distance to span ratio for the extrapolation of near-field pressure signatures is described and discussed. This study was to be done in two wind-tunnel facilities with two wind-tunnel models. At this time, only the first half had been completed, so the scope of this report is limited to the design of the models, and to an analysis of the first set of measured pressure signatures. The results from this analysis showed that the pressure signatures measured at separation distances of 2 to 5 span lengths did not show the desired low-boom shapes. However, there were indications that the pressure signature shapes were becoming 'flat-topped'. This trend toward a 'flat-top' pressure signatures shape was seen to be a gradual one at the distance ratios employed in this first series of wind-tunnel tests.

Mack, Robert J.↗
NASA NTRS1980

Spectral structure of pressure measurements made in a combustion duct

The spectral structure of pressure measurements made in a ducted combustion test facility are studied. Dispersion and attenuation of acoustic plane waves may occur in the duct at low frequencies due to combustor emissions and affect the spectral structure. A model that considers the propagation of plane waves through a cloud of particles in a flowing gas and which includes heat transfer between soot particles and the gas is discussed. Experimental results are compared with theory.

Miles, J. H.↗
NASA NTRS1996

Validation of UARS Microwave Limb Sounder Temperature and Pressure Measurements

The accuracy and precision of the Upper Atmosphere Research Satellite (UARS) Microwave Limb Sounder (MLS) atmospheric temperature and tangent-point pressure measurements are described. Temperatures and tangent-point pressure are retrieved from a 15-channel 63-GHz radiometer measuring O 2 microwave emissions from the stratosphere and mesosphere.

atmospheric↗
NASA NTRS1994

Experimental measurements and analytical analysis related to gas turbine heat transfer. Part 1: Time-averaged heat-flux and surface-pressure measurements on the vanes and blades of the SSME fuel-side turbine and comparison with prediction. Part 2: Phase-resolved surface-pressure and heat-flux measurements on the first blade of the SSME fuel-side turbine

Time averaged Stanton number and surface-pressure distributions are reported for the first-stage vane row, the first stage blade row, and the second stage vane row of the Rocketdyne Space Shuttle Main Engine two-stage fuel-side turbine. Unsteady pressure envelope measurements for the first blade are also reported. These measurements were made at 10 percent, 50 percent, and 90 percent span on both the pressure and suction surfaces of the first stage components. Additional Stanton number measurements were made on the first stage blade platform blade tip, and shroud, and at 50 percent span on the second vane. A shock tube was used as a short duration source of heated and pressurized air to which the turbine was subjected. Platinum thin-film heat flux gages were used to obtain the heat flux measurements, while miniature silicon-diaphragm flush-mounted pressure transducers were used to obtain the pressure measurements. The first stage vane Stanton number distributions are compared with predictions obtained using a version of STAN5 and a quasi-3D Navier-Stokes solution. This same quasi-3D N-S code was also used to obtain predictions for the first blade and the second vane.

Source record↗
NASA NTRS1959

Flow Characteristics About Two Thin Wings of Low Aspect Ratio Determined from Surface Pressure Measurements Obtained in Flight at Mach Numbers from 0.73 to 1.90

Surface pressure measurements were obtained at three chordwise stations on the wings of the X-3 and X-lE airplanes at Mach numbers from 0.73 to 1.13 for the X-3, and from 0.82 to 1.90 for the X-IE. Leading-edge separation is present on the X-3 wing at a Mach number of about 0.73 and an angle of attack of about 6 deg. However., when the Mach number is increased to 0.88, the trailing-edge separation dominates the pressure distribution and no leading-edge separation is visible although it is anticipated at the higher angles of attack shown. Conversely, the X-lE wing shows no indication of leading-edge separation within the scope of this investigation, but an overexpansion immediately behind the leading edge is present at a Mach number of approximately 0.82. Two separate normal shocks are present on the X-3 wing at a Mach number of about 0.88 and at a low angle of attack as an effect of wing geometry. These shocks merge to form a single shock when the angle of attack is increased to about 6 deg. At supersonic speeds the upper-surface expansion on the X-lE wing is limited by the approach of the pressure coefficients to the pressure coefficient for a vacuum.

Taillon, Norman V.↗
NASA NTRS1972

Rotating pressure measuring system for turbine cooling investigations

The development of a 10-channel rotating pressure measuring system capable of operation to speeds of 9000 rpm at transducer temperatures of about 320 K (120 F) is described. Variable-reluctance pressure transducers were mounted in the rotating system for sensing pressure. Rotating performance tests on a spin rig showed that the output data from 7 of the 10 transducers tested were within a desired system error of 3 percent. However, the error of the output data from three other transducers was as large as 8 percent of 9000 rpm. It was concluded from these test results that a rotating screening method was necessary to evaluate each pressure transducer channel within a system that will be used under rotating conditions.

Pollack, F. G.↗
NASA NTRS1974

Pressure measurements on the leading edge of a swept wing at Mach 2.2

Detailed pressure measurements were made on a flat semispan swept wing with a rounded leading edge at Mach number 2.2 through a range of Reynolds numbers. Pressure orifices were distributed in the streamwise direction at five spanwise stations on the leading edge and on the upper and lower surfaces. No significant amount of leading-edge suction was found, but the pressures and integrated normal forces on the upper and lower surfaces indicate the presence of a vortex lift.

Sorrells, R. B., III↗