The Influence of Incidence Angle on the Discharge Coefficient for Rotating Radial Orifices

Idris, Mohd Azree; Pullen, Keith; Read, R. B.

doi:10.1115/gt2004-53237

Cited by 13 publications

(9 citation statements)

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“…Considering the similarity of the flow structures of the rotating orifice and the tube entrance, the pressure drop at the tube entrance is analyzed in the way applied in the rotating orifice problem (Idris, Pullen, & Read, 2004). Figure 10 shows the velocity triangle of air at the tube entrance under a rotating coordinate system.…”

Section: The Pressure Drop At the Tube Entrancementioning

confidence: 99%

A mathematical model for predicting the pressure drop in a rotating cavity with a tubed vortex reducer

Song

Yan

Mao

et al. 2019

Engineering Applications of Computational Fluid Mechanics

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The flow characteristics of a tubed vortex reducer, which was used to reduce the pressure drop in an aeroengine air bleed system, were studied in this paper. Accurate prediction of the pressure drop in a rotating cavity with tubed vortex reducer installed is important, but the complex flow structure results in complicated local loss characteristic at the tube entrance, which is difficult to estimate. In this paper, a mathematical model for predicting the pressure drop in a rotating cavity with a tubed vortex reducer was established. For the first time, the effect of the local loss at the tube entrance under rotating conditions was considered, and a method of introducing the local loss factor was established based on a research method applied in traditional rotating orifices. Furthermore, the flow characteristics and the distribution of the static pressure in the tubed vortex reducer cavity were studied by the CFD method and experimental tests, and the pressure information inside the tubed vortex reducer was obtained by detailed experimental testing. This study reveals that the local loss characteristics at the tube entrance are mainly influenced by the incident angle; the closer the incident angle is to 0, the greater the speed coefficient is. The pressure drop at the tube entrance is important and represents approximately 10% of the total pressure drop. The mathematical model shows good accuracy for calculating the pressure drop, with an average error of approximately 2% compared to the experimental data.

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Section: The Pressure Drop At the Tube Entrancementioning

confidence: 99%

A mathematical model for predicting the pressure drop in a rotating cavity with a tubed vortex reducer

Song

Yan

Mao

et al. 2019

Engineering Applications of Computational Fluid Mechanics

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show abstract

“…However, the effect of rotation was not considered in their study. Idris et al [19,20] confirmed that the discharge coefficient is strongly influenced by the rotation with both numerical and experimental methods. They investigated the effect of the circumferential inclination angle on the discharge coefficient of rotating orifices for the first time.…”

Section: Introductionmentioning

confidence: 94%

An Investigation into the Flow of Rotating Orifices with Euler Angle and the Calculation Model of Discharge Coefficient Considering the Effect of Comprehensive Incidence Angle

et al. 2022

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As a typical flow element in an aero-engines, orifices play a vital role in the distribution and control of the mass flow rate within the secondary air system. In particular, rotating orifices with complex geometry (Euler angles) may significantly vary the discharge coefficients. Understanding the discharge coefficients of these orifices may guarantee a more reasonable distribution of the internal flow within the air system. This contributes to the safety, reliability, and structural integrity of the aero-engine under the all-inclusive line. In this paper, the flow state within the orifice and the discharge coefficient have been studied under the condition of different Euler angles (α0=0–30° and β0=0–30°) and rotational speeds (0–10,000 r/min). The comprehensive incidence angle is proposed to describe the combined effect of Euler angles and rotation. The correlation between the discharge coefficient and the comprehensive incidence angle is also given. At the same time, a general calculation model of the orifices is established considering the effect of the comprehensive incidence angle. The results indicate that the effects of the circumferential inclination angle, radial inclination angle, and rotation may be more clearly expressed by the comprehensive incidence angle. The larger discharge coefficient is obtained when the comprehensive incidence angle is close to 0, and under the fixed rotational speed and flow condition, the maximum discharge coefficient can be obtained by arranging the appropriate Euler angle for the orifice. Compared with the experimental results in the published literature, the calculation results of the model have an overall error of less than 6%. The calculation accuracy is high enough for the one-dimensional simulation of the secondary air system.

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“…Comparison of tested orifice geometries with the literature data. 2,4,[6][7][8]10 The core of the rig (Figure 3) consists of four machined aluminium (AlMgSi1) parts, which form the main square section flow channel with dimensions of 20 Â 20 mm 2 . This channel is sealed by round cord.…”

Section: Test Setup Test Rigmentioning

confidence: 99%

“…Idris et al [7][8][9] performed tests and CFD calculations for rotating axial and radial orifices. They assessed orifices with inclinations up to 30 in and against approaching inlet cross-flow.…”

Section: Introductionmentioning

confidence: 99%

Discharge coefficient measurements of round, inclined orifices with inlet cross-flow in and against direction of inclination

Hüning

2012

Proceedings of the Institution of Mechanical Engineers, Part C:

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In an effort to improve the validated understanding of aerodynamic losses across orifices, this publication describes discharge coefficient measurements, derived from a specially designed test rig. This rig contains a straight, square section main channel (20 Â 20 mm 2 ) with exchangeable orifice plates at one side wall with 7 mm hole diameters. The channel was supplied with compressed air at between about zero velocity and nearly the speed of sound. Static pressure ratios across orifices were varied between 1.05 and 2 in addition. Test orifices had inclinations of 0 , 30 and 60 in and against inlet cross-flow. Further, orifice length-to-diameter ratios were varied to 0.5, 1 and 2. Orifice inlet and outlet corners were sharp. The main channel velocity was determined using a pitot tube, a thermocouple and flush-mounted static pressure off-takes. Orifice downstream pressure was measured by a flush mounted static pressure off-take. Orifice through flow was determined by a calibrated hot film measurement device with constant temperature difference control, equipped with an additional thermocouple to determine fluid properties.

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The Influence of Incidence Angle on the Discharge Coefficient for Rotating Radial Orifices

Cited by 13 publications

References 0 publications

A mathematical model for predicting the pressure drop in a rotating cavity with a tubed vortex reducer

A mathematical model for predicting the pressure drop in a rotating cavity with a tubed vortex reducer

An Investigation into the Flow of Rotating Orifices with Euler Angle and the Calculation Model of Discharge Coefficient Considering the Effect of Comprehensive Incidence Angle

Discharge coefficient measurements of round, inclined orifices with inlet cross-flow in and against direction of inclination

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