A multielement probe for coincident temperature and pressure measurements
Small, multielement probes are described which measure total pressure and temperature coincidentally at one or several points in gas stream.
Engineering topics
Publications and source records attributed to Krause, L. N..
Small, multielement probes are described which measure total pressure and temperature coincidentally at one or several points in gas stream.
A number of total-pressure tubes were tested in a nonsteady flow generator in which the fraction of period that pressure is a maximum is approximately 0.8, thereby simulating turbomachine-type flow conditions. Most of the tubes indicated a pressure which was higher than the true average. Organ-pipe resonance which further increased the indicated pressure was encountered with the tubes at discrete frequencies. There was no obvious combination of tube diameter, length, and/or geometry variation used in the tests which resulted in negligible averaging error. A pneumatic-type probe was found to measure true average pressure and is suggested as a comparison instrument to determine whether nonlinear averaging effects are serious in unknown pulsation profiles.
Nonsteady flow probe uses miniature pressure transducers mounted within probe support very close to tube inlets. Response speed depends on internal volume between tube inlet and pressure transducer location.
Design features and characteristics of a means for measuring total temperature and total pressure at a single point in a gas stream are presented. A rake that provides five such combination measurements is described. Experimental data are included for the aerodynamic recovery and time response of the temperature sensor and for the flow-angle sensitivity of both the temperature and pressure sensors. Data were obtained over a subsonic Mach number range of 0.3 to 0.9 as well as at a Mach number of 1.4.
A number of total-pressure tubes were tested in a non-steady flow generator in which the fraction of period that pressure is a maximum is approximately 0.8, thereby simulating turbomachine-type flow conditions. Most of the tubes indicated a pressure which was higher than the true average. Organ-pipe resonance which further increased the indicated pressure was encountered within the tubes at discrete frequencies. There was no obvious combination of tube diameter, length, and/or geometry variation used in the tests which resulted in negligible averaging error. A pneumatic-type probe was found to measure true average pressure, and is suggested as a comparison instrument to determine whether nonlinear averaging effects are serious in unknown pulsation profiles. The experiments were performed at a pressure level of 1 bar, for Mach number up to near 1, and frequencies up to 3 kHz.
Inlet nozzle geometry effects on subsonic flow characteristics of miniature total pressure tubes including pitot tube static and dynamic pressure and flow velocity measurements
Supersonic mass flux probe description, discussing inlet geometry, angle of attack and Reynolds and Mach numbers effects on performance
Flow direction generator for testing sensitivity of flowmeter to unsteady pressure
Mass-flux probe as useful diagnostic tool in high Mach number and high enthalpy flows
Nonsteady air flow direction generation and measurement, comparing three-tube probe with hot- wire anemometer data
Temperature, pressure and flow direction probe in rotating fluid machines analysis
Fixed-position probes for determination of flow direction in one and two planes are tested over a wide range of Reynolds numbers and Mach numbers. The work is limited to tests of a single probe design for two dimensional flow and a single design for three dimensional flow.
Performance of mass flux probe in Mach 3 stream
Flow direction measurement with fixed-position probes
Fixed position pressure probe for measuring subsonic flow direction over range of Reynolds number, Mach number and flow angle
Multiple function combination probe design for compressor and turbine air flow research
Venturi meter with separable diffuser and radial outward step at transition from throat to diffuser, noting effect of step on efficiency
Probe consists essentially of a tube with a supersonic inlet pointed into the gas stream. The mass flow rate through the tube is determined at a flow measuring station.