AN ANALYSIS OF INITIAL STATIC PRESSURE PROBE MEASUREMENTS IN A LOW-DENSITY HYPERVELOCITY WIND TUNNEL

1963 ◽  
Author(s):  
David E. Boylan
Keyword(s):  
Wind Tunnel ◽  
Static Pressure ◽  
Pressure Probe ◽  
Low Density ◽  
Probe Measurements

scholarly journals Transonic Probe Blockage Effects in a Calibration Wind–Tunnel and Stator Blade Passage

1996 ◽  
Author(s):  
Frank Truckenmüller ◽  
Martin Renner ◽  
Heinz Stetter ◽  
Hans–Georg Hosenfeld
Keyword(s):  
Wind Tunnel ◽  
Static Pressure ◽  
Guide Vane ◽  
Calibration Procedure ◽  
Wind Tunnels ◽  
Pressure Probe ◽  
Blade Passage ◽  
Stator Blade ◽  
Flow Through ◽  
Transonic Turbine

Probe blockage effects are presented for transonic flow through a calibration wind–tunnel as well as through a guide vane row in a three–stage model turbine. Accurate experimental data from measurements in a transonic turbine are needed for the verification of CFD results. The accuracy of etatic pressure measurements in transonic turbine stages is severely affected by the pressure probe stem disturbing the surrounding flow–field. These disturbance effects are present during calibration procedures in wind–tunnels, as well as during measurements in–between turbomachinery blade rows. Therefore, the phenomenon associated with this blockage effect must be investigated for both procedures. The influence of the blockage ratios on the static pressure readings of the four–hole wedge probe during the calibration procedure is investigated for two different wind–tunnels. The aim is to measure the blockage effects on the blade passage flow which are produced by a pneumatic pressure probe immersed in the flow between two adjacent blade rows. In order to measure these effects, two stator blades are instrumented with static pressure taps along the blade chord, as well as along the blade span. During the investigations, the radial and circumferential positions of the probes relative to the blade channel are varied. Pressure probe readings of two four–hole wedge probes with different stem diameters are compared as well as correlated to the static pressure readings of the stator blade pressure taps. The apparent deviations of the different readings are discussed.

scholarly journals A preliminary study on static pressure probe mobile measurement method for flow field in transonic wind tunnel

2021 ◽  
Vol 39 (4) ◽  
pp. 786-793
Author(s):  
Haijun Deng ◽  
Bo Xiong ◽  
Xinfu Luo ◽  
Shaozun Hong ◽  
Qi Liu ◽  
...  
Keyword(s):  
Mach Number ◽  
Wind Tunnel ◽  
Flow Field ◽  
Static Pressure ◽  
Wind Tunnel Test ◽  
Flow Characteristics ◽  
Pressure Probe ◽  
Number Distribution ◽  
Mach Number Distribution ◽  
Transonic Wind Tunnel

The axial Mach number distribution of the core flow for model in a transonic wind tunnel is an important index to evaluate the performance of the flow field, which is usually measured by the centerline probe. In order to simulate the incoming flow characteristics without interference, the probe will extend from the support section to the shrinkage section, so the probe usually must has longer inches, more static pressure measuring points and smaller blockage requirements. In order to study the influence of the points of the centerline probe on the uniformity distribution of flow field, a new static pressure probe is designed, which is smaller and shorter than the centerline probe. On the basis of the stability of the flow field, the Mach number distribution of the flow field measured by the static pressure probe which is driven by the moving measuring mechanism. The characteristics of the measured values are studied by wind tunnel test. The results show that: when Ma ≤ 0.95, the overall distribution and value of Mach number obtained by the static pressure probe is basically the same as those obtained by the centerline probe, but some flow field details, which mainly shows that Mach number of the static pressure probe has smaller fluctuation, higher accuracy and better uniformity index.

Effect of an Axially Tilted Variable Stator Vane Platform on Penny Cavity and Main Flow

2021 ◽  
Author(s):  
Johannes Janssen ◽  
Daniel Pohl ◽  
Peter Jeschke ◽  
Alexander Halcoussis ◽  
Rainer Hain ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Flow Region ◽  
Cavity Flow ◽  
Main Flow ◽  
Pressure Probe ◽  
Stator Vane ◽  
Cfd Analyses ◽  
Annular Cascade ◽  
The Impact ◽  
Variable Stator

Abstract This paper presents the impact of an axially tilted variable stator vane platform on penny cavity flow and passage flow, with the aid of both optical and pneumatic measurements in an annular cascade wind tunnel as well as steady CFD analyses. Variable stator vanes (VSVs) in axial compressors require a clearance from the endwalls. This means that penny cavities around the vane platform are inevitable. Production and assembly deviations can result in a vane platform which is tilted about the circumferential axis. Due to this deformation, backward facing steps occur on the platform edge. Penny cavity and main flow in geometries with and without platform tilting were compared in an annular cascade wind tunnel, which comprises a single row of 30 VSVs. Detailed particle image velocimetry (PIV) measurements were conducted inside the penny cavity and in the vane passage. Steady pressure and velocity data was obtained by two-dimensional multi-hole pressure probe traverses in the inflow and the outflow. Furthermore, pneumatic measurements were carried out using pressure taps inside the penny cavity. Additionally, oil flow visualization was conducted on the airfoil, hub, and penny cavity surfaces. Steady CFD simulations with boundary conditions, according to the measurements, have been benchmarked against experimental data. The results show that tilting the VSV platform reduces the mass flow into and out of the penny cavity. By decreasing penny cavity leakage, platform tilting also affects the passage flow where it leads to a reduced turbulence level and total pressure loss in the leakage flow region. In summary, the paper demonstrates the influence of penny platform tilting on cavity flow and passage flow and provides new insights into the mechanisms of penny cavity-associated losses.

Fast pressure probe measurements of a high-velocity plasma plume

2009 ◽  
Vol 16 (6) ◽  
pp. 064502 ◽  
Author(s):  
S. Messer ◽  
A. Case ◽  
R. Bomgardner ◽  
M. Phillips ◽  
F. D. Witherspoon
Keyword(s):  
High Velocity ◽  
Plasma Plume ◽  
Pressure Probe ◽  
Probe Measurements

The Development of Extremely-Compact Static Pressure Probe for the Simultaneous Measurement of Pressure and Velocity in the Turbulent Flows

2011 ◽  
Author(s):  
Kazuhiro Onishi ◽  
Osamu Terashima ◽  
Yasuhiko Sakai ◽  
Kouji Nagata
Keyword(s):  
Turbulent Flows ◽  
Simultaneous Measurement ◽  
Measurement Accuracy ◽  
Static Pressure ◽  
Pressure Tube ◽  
Pressure Probe ◽  
External Diameter ◽  
Space Resolution ◽  
Mems Microphone ◽  
Yaw Angle

A new static pressure probe was developed to improve the space resolution and the measurement accuracy of the combined probe for the simultaneous measurement of the static pressure and the velocity in turbulent flows. The external diameter of the static pressure tube is 0.3 mm and its internal diameter is 0.2 mm. There are 8 static pressure holes on the wall of the static pressure tube and their diameters are 0.1 mm. The MEMS microphone is used as the pressure sensor and embedded inside the flare of the static pressure tube. The diameter of the MEMS microphone is 2.54 mm and has the wide range flat frequency response. The measurement results by the new static pressure probe in the two-dimensional turbulent jet show that the measurement accuracy of the static pressure probe is sufficient and the seven-thirds power law is clearly observed in the power spectra of the fluctuating pressure measured at the position of a half width of the mean velocity distribution in the cross-streamwise direction apart from the jet center line. In addition, the yaw angle characteristics of this new pressure probe shows that the measurement accuracy of the static pressure has less dependency on the yaw angle of the probe to the flow direction than the one of the previous static pressure tube (its external diameter is 0.5 mm). From these results, it is found that the new static pressure probe is effective for the measurement of static pressure in turbulent flows and useful to improve the space resolution and the measurement accuracy of the combined probe for the simultaneous measurement of the velocity and the static pressure. By using this static pressure tube, the space resolution of the combined probe is reduced approximately 40%. Further, by combing two X-type hot-wire probes with the new pressure probe, the simultaneous measurement of three velocity components and static pressure is realized.

scholarly journals The Effect of Tip Clearance Gap Size and Wall Rotation on the Performance of a High-Speed Annular Compressor Cascade

1998 ◽  
Author(s):  
A. Doukelis ◽  
K. Mathioudakis ◽  
K. Papailiou
Keyword(s):  
High Speed ◽  
Static Pressure ◽  
Tip Clearance ◽  
Performance Characteristics ◽  
Compressor Cascade ◽  
Tip Clearance Flow ◽  
Pressure Distributions ◽  
Clearance Flow ◽  
Overall Performance ◽  
Probe Measurements

The performance of a high speed annular compressor cascade for different clearance gap sizes, with stationary or rotating hub wall is investigated. Five hole probe measurements, conducted at the inlet and outlet of the cascade, are used to derive blade performance characteristics, in the form of loss and turning distributions. Characteristics are presented in the form of circumferentially mass averaged profiles, while distributions on the exit plane provide information useful to interpret the performance of the blading. Static pressure distributions on the surface of the blades as well as inside the tip clearance gap have also been measured. A set of four clearance gap sizes, in addition to zero clearance data for the stationary wall, gives the possibility to observe the dependence of performance characteristics on clearance size, and establish the influence of rotating the hub. Overall performance is related to features of the tip clearance flow. Increasing the clearance size is found to increase losses in the clearance region, while it affects the flow in the entire passage. Wall rotation is found to improve the performance of the cascade.

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