A novel method for extending the calibration range of five-hole probe for highly three-dimensional flows
TL;DR: In this paper, a method to extend this range by avoiding singularity is developed allowing calibration of a five-hole probe up to much larger angles of pitch and yaw, which can be successfully extended to angles of up to ±75°.
About: This article is published in Flow Measurement and Instrumentation.The article was published on 2002-03-01. It has received 80 citations till now. The article focuses on the topics: Wind tunnel & Calibration.
Citations
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TL;DR: In this paper, the suitability of numerical approach in modelling various features of a ventilator flow was explored using the standard k-ɛ turbulence model with multiple reference frame (MRF) meshing technique.
54 citations
TL;DR: In this article, a study on an 80mm diameter sphere with localised synthetic jet orifices was conducted in an 18in×18-in open circuit closed test-section wind tunnel at a Reynolds number of 5×104.
53 citations
TL;DR: A review of existing and emerging wind power technologies in light of the evident trends of the industry, and describes the challenges these technologies will face if wind turbines were to become a significant and reliable source of clean energy of the future is presented in this paper.
Abstract: This paper presents a review of existing and emerging wind power technologies in light of the evident trends of the industry, and describes the challenges these technologies will face if wind turbines were to become a significant and reliable source of clean energy of the future. Apart from withstanding both the cost pressures against other forms of renewable and non-renewable technologies and the technical and design challenges for efficient and enhanced performance under all weather conditions, a major hurdle that must be overcome is to make the wind farms acceptable to the general public. Although there is now a greater awareness amongst world population about the perils of climate change, the issue of wind turbine generated noise, land use, fauna deaths and visual impacts have to be adequately addressed to ensure continued political and public support for the technology to flourish. These are the viewpoints against which emerging technologies are reviewed and the capacity of some of them to address these issues explored.
44 citations
TL;DR: In this paper, the authors investigated the effect of the inclination of the inclined roof on the performance of a turbine ventilator on a simulated rooftop and found that the effect is minimal in extracting air from a building at low wind speed.
42 citations
TL;DR: In this paper, a functional relationship is developed, based on theoretical considerations, that relates the port pressure directly to the flow properties and details a procedure that enables flow properties to be determined from the measured pressures of the multihole probe.
Abstract: It is common in the calibration of multihole probes to curve-fit the calibration data in order to determine a relationship between measured port pressures and flow properties. The parameters used in these techniques typically lack a theoretical background. In this article, a functional relationship is developed, based on theoretical considerations, that relates the port pressure directly to the flow properties and details a procedure that enables flow properties to be determined from the measured pressures of the multihole probe. The method is simple, easy to implement and provides a better understanding of the multihole probe operation in a three-dimensional flow.
41 citations
Cites methods or result from "A novel method for extending the ca..."
...For low angles in pitch and yaw, it can be seen that the ‘‘goodness of fit’’, in the values of R 2 are comparable to those obtained by Morrison et al. (1998), who used curve-fit coefficients that have been demonstrated to have the potential to cause problems ( Pisasale and Ahmed 2002a, 2002b )....
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...The probe was placed in the flow through the use of an apparatus, mounted on the wind tunnel roof, that could vary the pitch and yaw angle of the probe in relation to the freestream flow ( Pisasale and Ahmed 2002a ), as shown in Fig. 2. A Pitot-static tube was also placed in the flow in order to record the total and static pressure of the freestream....
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...In our recent works ( Pisasale and Ahmed 2002a, 2002b ) we demonstrated that this method encounters singularity and so is limited to low flow angularity....
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...In our solution ( Pisasale and Ahmed 2002a ) we correct for the singularity so that the graphical technique of Treaster and Yocum (1971) could be extended to large flow angles....
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...However, these methods are based on calibration coefficients similar to those of Treaster and Yocum (1979) that have the demonstrated potential to be singular ( Pisasale and Ahmed 2002a, 2002b )....
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References
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18 Jan 1978
Abstract: : In many complex flow fields such as those encountered in turbomachines, the experimental determination of the steady-state, three-dimensional characteristics of the flow field are frequently required. If space limitations or other considerations make nulling techniques impractical, five- hole probles in a non-nulling mode can be employed. However, this application requires complete three-dimensional calibration data which are not usually supplied by commercial vendors. Presented in this paper are the results of programs to calibrate and employ five-hole probes of both angle-tube and prismatic geometries. Included are descriptions of the calibration technique, typical calibration data, and an accompanying discussion of the application or interpolation procedure. Also documented are the variations in the calibration data due to Reynolds number and wall proximity effects. Typical measured data are included and, where applicable, these data are validated by comparison with data obtained using other types of velocity measuring instrumentation.
178 citations
01 Jan 1978
TL;DR: In this article, the results of programs to calibrate and employ five-hole probes of both angle-tube and prismatic geometries are presented, along with typical calibration data, and an accompanying discussion of the application or interpolation procedure.
Abstract: : In many complex flow fields such as those encountered in turbomachines, the experimental determination of the steady-state, three-dimensional characteristics of the flow field are frequently required. If space limitations or other considerations make nulling techniques impractical, five- hole probles in a non-nulling mode can be employed. However, this application requires complete three-dimensional calibration data which are not usually supplied by commercial vendors. Presented in this paper are the results of programs to calibrate and employ five-hole probes of both angle-tube and prismatic geometries. Included are descriptions of the calibration technique, typical calibration data, and an accompanying discussion of the application or interpolation procedure. Also documented are the variations in the calibration data due to Reynolds number and wall proximity effects. Typical measured data are included and, where applicable, these data are validated by comparison with data obtained using other types of velocity measuring instrumentation.
92 citations
TL;DR: In this paper, a refined calibration technique for five-hole pressure probes operating in the non-nulling mode is presented, where the shape of the 3D surfaces are used to determine if a probe should not be used due to any machining abnormality or damage a probe has sustained.
65 citations
TL;DR: In this paper, a miniature five-hole pressure probe was developed to measure three mean velocity components using a non-nulling procedure at individual locations in a curved channel where differential pressures are low, flow is three-dimensional and laminar, and spatial resolution and flow blockage effects are important considerations.
Abstract: A miniature five-hole pressure probe is described which has a probe tip diameter of 122 mm The probe was developed to measure three mean velocity components using a non-nulling procedure at individual locations in a curved channel where differential pressures are low, flow is three-dimensional and laminar, and spatial resolution and flow blockage effects are important considerations Calibration coefficients are presented for Reynolds numbers based on probe tip diameter ranging from 80 to 400 Coefficients for yaw angle, pitch angle, total pressure and total minus static pressure are independent of Reynolds number within experimental uncertainties Experimental details unique to the use of the miniature probe are also given along with distributions of mean velocity and mean vorticity over a portion of the 127 mm*5080 mm cross section of a curved channel At a Dean number of 119 (mean streamwise velocity approximately 12 m s-1), structural characteristics of Dean vortices are evident from contours of the streamwise velocity, the total pressure and the streamwise component of mean vorticity determined from secondary flow vectors
62 citations
TL;DR: In this paper, a calibration method for a five-hole spherical Pitot probe by which the direction of a velocity vector is fixed by two Cartesian angles, one lying in the horizontal equatorial plane and the other in a vertical meridian plane containing the velocity vector, is described.
Abstract: A calibration method is described for a five-hole spherical Pitot probe by which the direction of a velocity vector is fixed by two Cartesian angles, one lying in the horizontal equatorial plane and the other in a vertical meridian plane containing the velocity vector Measurements are found to be possible within the range of up to 65° half cone angle from the probe axes
28 citations