Numerical Flow Analysis in a Subsonic Vaned Radial Diffuser With Leading Edge Redesign

Casartelli, Ernesto; Saxer, A. P.; Gyarmathy, G.

doi:10.1115/1.2841219

Cited by 14 publications

(13 citation statements)

References 8 publications

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“…In Casartelli et al (1997) the redesign procedure was presented. The CFD results were validated by comparing the pressure rise (Dp) vs. flow coefficient (9) characteristic for the standard and a redesigned geometry, showing that the measured tendencies were properly captured numerically.…”

Section: Comparison With Experimental Datamentioning

confidence: 99%

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Performance Analysis in a Subsonic Radial Diffuser

Casartelli¹,

Saxer²,

Gyarmathy³

1998

Volume 1: Turbomachinery

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Steady-state numerical investigations in a subsonic vaned radial diffuser are presented. The 3D flow field has been computed with a commercial Navier-Stokes code (TASCflow), using two different types of axially variable but circumferentially uniform inlet flow conditions, one based on realistic (measured) time-averaged impeller outflow, the other on an idealized distribution. Two different vane leading-edge shapes were investigated. The leading edge redesign is based on the 2D analysis and inverse-design software package MISES. For a complete operating speed line a detailed analysis of the flow structure and loss distribution within the diffuser is presented and the results obtained for the different inlet flow conditions and geometries are critically compared. The performance of the diffuser and its subcomponents is evaluated in terms of dimensionless quantities such as blockage, total-pressure-loss and pressure-recovery coefficients. Based on the comparisons and the cross performance analysis of the various effects due to leading edge redesign and different inlet velocity profiles, several design guidelines are postulated.

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Section: Comparison With Experimental Datamentioning

confidence: 99%

“…In Casartelli et al (1997) a strategy has been presented for the redesign of the leading edge domain of vaned diffusers. It was based on the 2D analysis/ inverse design software MISES by Drela a al.…”

Section: Introductionmentioning

confidence: 99%

Performance Analysis in a Subsonic Radial Diffuser

Casartelli¹,

Saxer²,

Gyarmathy³

1998

Volume 1: Turbomachinery

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“…For example, Yoshinaga et al [8] experimentally studied the effect of diffuser inlet on the stage efficiency of a model compressor rig, and the results showed that the leading edge shape of vanes had considerable influence on the performance. Casartelli et al [9] modified the vane leading edge geometry in a subsonic radial diffuser. Their numerical results showed that the stage performance could be improved.…”

Section: Introductionmentioning

confidence: 99%

The influence of the geometry of the leading edge of diffuser vanes on the noise generated by a centrifugal fan

Zhang

Gong

2010

Proceedings of the Institution of Mechanical Engineers, Part A:

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An experimental study is described to investigate the influence of diffuser vane leading edge on the noise behaviour of a centrifugal fan. The geometric shapes of the diffuser vane leading edge refer to the diffuser inlet radius, and the broken and inclined leading edges. The sound pressure level and pressure rise of the centrifugal fan were measured in a semianechoic chamber. The rotational speed of the test fan varied from 20 000 to 35 000 r/min; the flow coefficient was in the range of 0.02-0.14. The results show that: (a) by using the inclined leading edge vaned diffuser (ILEVD) with proper inclined angle, the overall fan noise is reduced by 3.6 dB(A), and the fan performance is improved; (b) when the diffuser leading edge radius R 3 /R 2 increases from 1.03 to 1.07, the tones are reduced whereas the broadband noise is almost unchanged; and (c) the influence of the broken leading edge diffuser on the overall fan noise and performance is negligible, although the tonal noise is reduced by 4 dB(A). In order to better understand the behaviour of the ILEVDs, a numerical simulation has been carried out on steady three-dimensional flows. The results indicate that the flow condition improves by the application of the ILEVD.

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“…The latter is specially designed for the visualisation of large-scale flow phenomena like rotating stall (Gyarmathy (1996), File et al (1997)). Furthermore CFD calculations are performed with the TascFlow code (Casartelli et al (1997(Casartelli et al ( , 1998). Of special interest for experiments and CFD calculations is the flow field in the diffuser, because this part is mainly responsible for limiting the stable operating range.…”

Section: Introductionmentioning

confidence: 99%

Investigations of Turbulent Flow in a Centrifugal Compressor Vaned Diffuser by 3-Component Laser Velocimetry

Stahlecker¹,

Gyarmathy²

1998

Volume 1: Turbomachinery

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The unsteady 3D impeller exit and vaned diffuser flow of a high-subsonic centrifugal compressor has been investigated with an LDV system. Time-resolved 3D velocity measurements were taken along a streampath at 8 positions from impeller exit downwards through the vaned diffuser and at 18 positions from hub to casing at each station. The compressor was operated at its best point at a rim Mach number of Mu = 0.75. Time-resolved (phase averaged) angle and velocity profiles are presented for 2 positions along the streampath. The time-averaged velocity, deterministic fluctuation intensity, turbulence intensity, and in-plane Reynolds sheer stress profiles, presented for all stations, show the evolution of flow and permit comparisons to in-house CFD calculations to be made. The flow leaving the impeller enters the diffuser with an asymmetric and distorted velocity profile. It is shown that the deterministic fluctuations caused by the jet/wake are quickly damped along the streampath. The results illustrate the deceleration of the flow arriving near the hub in the diffuser channel. The deceleration is accompanied by a sharp increase of turbulence. Near the casing, where the approach velocity is low, no deceleration occurs and the Reynolds stresses are high. Turbulence in the in-plane flow can be regarded as isotropic whereas the axial fluctuations clearly show a high amount of anisotropicity. The narrow diffuser passage required special optical measures for permitting close-to-wall LDV measurements. The experiences are described.

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Numerical Flow Analysis in a Subsonic Vaned Radial Diffuser With Leading Edge Redesign

Cited by 14 publications

References 8 publications

Performance Analysis in a Subsonic Radial Diffuser

Performance Analysis in a Subsonic Radial Diffuser

The influence of the geometry of the leading edge of diffuser vanes on the noise generated by a centrifugal fan

Investigations of Turbulent Flow in a Centrifugal Compressor Vaned Diffuser by 3-Component Laser Velocimetry

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