Rotor wake characteristics of a transonic axial-flow fan

Hathaway, Michael D.; Gertz, J. B.; Strazisar, A. J.

doi:10.2514/3.9527

Cited by 28 publications

(6 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As previously mentioned, however, unresolved unsteadiness as defined herein includes any unsteadiness not correlated with the fundamental rotor rotational frequency. In the case of the present research fan, part of the unresolved unsteadiness is due to vortex shedding from the rotor trailing edge (14). This vortex shedding increases the magnitude of the UVC relative to that which would exist in the absence of the shedding.…”

Section: Correlations Of Unresolved Velocity Fluctuationsmentioning

confidence: 75%

Measurements of the Unsteady Flow Field Within the Stator Row of a Transonic Axial-Flow Fan: II — Results and Discussion

Hathaway

Okiishi

Suder

et al. 1987

Volume 1: Turbomachinery

Self Cite

View full text Add to dashboard Cite

Results of detailed unsteady velocity field measurements made within the stator row of a transonic axial-flow fan are presented. Measurements were obtained at midspan for two different stator blade rows using a laser anemometer. The first stator row consists of double-circular-arc airfoils with a solidity of 1.68. The second stator row features controlled-diffusion airfoils with a solidity of 0.85. Both stator configurations were tested at design-speed peak efficiency conditions. In addition, the controlled-diffusion stator was also tested at near-stall design-speed conditions. The procedures developed in Part I of this paper are used to identify the “rotor-wake-generated” and “unresolved” unsteadiness from the velocity measurements. (The term “rotor-wake-generated” unsteadiness refers to the unsteadiness generated by the rotor wake velocity deficit and the term “unresolved” unsteadiness refers to all of the remaining unsteadiness which contributes to the spread in the distribution of velocities such as vortex shedding, turbulence, etc.) Auto and cross correlations of these unsteady velocity fluctuations are presented in order to indicate their relative magnitude and spatial distributions. Amplification and attenuation of both rotor-wake-generated and unresolved unsteadiness are shown to occur within the stator blade passage.

show abstract

Section: Correlations Of Unresolved Velocity Fluctuationsmentioning

confidence: 75%

Measurements of the Unsteady Flow Field Within the Stator Row of a Transonic Axial-Flow Fan: II — Results and Discussion

Hathaway

Okiishi

Suder

et al. 1987

Volume 1: Turbomachinery

Self Cite

View full text Add to dashboard Cite

show abstract

“…As indicated, the flow turning angle 8 was underpredicted in all of the simulations, as was the loss coefficient C. The values of C obtained with transition suppressed until c 1<i0r4 are slightly lower, and therefore in worse agreement with the experimental result, than the values obtained without using the transition modification. Reduced skin friction on the suction surface upstream of the shock impingement point is the most likely cause of the lower Cr, It is possible that the high loss measured in the experiment was caused by vortex shedding, which can have a very significant effect [Currie, 1996] and has been observed in compressor rotors [Hathaway et al, 1985] and cascades [Paterson and Weingold, 19841, and/or unsteadiness of the passage shock. It should be mentioned that the flow was not separated, and the loss coefficient was only -0.075, when M, was reduced to 1.02 in the experiments.…”

Section: Dlr Tsg-9141( Compressor Cascadementioning

confidence: 96%

Comparison of ω-Based Turbulence Models for Simulating Separated Flows in Transonic Compressor Cascades

Currie

1998

Volume 1: Turbomachinery

View full text Add to dashboard Cite

Separated flows in the DLR transonic compressor cascades TSG-91-8K and TSG-89-5 are simulated with a quasi-3D Navier-Stokes code using the zonal k-ω/k-ϵ “Shear Stress Transport” two-equation turbulence model of Menter and the multiscale Reynolds stress model of Wilcox. Both of these models use the specific turbulent dissipation rate ω as the length scale variable. The models are also used to simulate the low speed, separated flow, adverse pressure gradient test case of Driver. While both models predict results which are in good agreement with experiment for the latter test case, they yield relatively poor results, particularly for losses, for the cascade test cases, especially TSG-89-5 where separation occurs from both the suction and pressure surfaces. It is known from the cascade test results that the separations are laminar, so some improvement in agreement is achieved by suppressing transition to the separation points in the simulations. The poor accuracy of the models is believed to be related to severe non-equilibrium of turbulence production and dissipation predicted after the shock-induced separations.

show abstract

“…7), one of these corresponding to a wake value and the other one to an "inviscid" flow value. This phenomenon may be explained by a non perfect axisymmetry of the blade row, or a possible vortex street structure in the rotor blade wake (15).…”

Section: E (%)mentioning

confidence: 99%

Laser Two-Focus Anemometry Investigation of the Flow Field Within a Supersonic Axial Compressor Rotor

Trébinjac

Vouillarmet

1990

Volume 5: Manufacturing Materials and Metallurgy; Ceramics; Structures and Dynamics; Controls, Diagnostics and Instrumentation;

View full text Add to dashboard Cite

Laser anemometer measurements have been performed within and downstream of a supersonic single-stage high-pressure compressor. At design point and with standard upstream conditions the maximum relative Mach number varies from 1.3 at the tip to 1.1 at the hub. The stage total pressure ratio is 1.84 and the specific mass flow 180 kg/s/m2. The laser two-focus anemometer has been completely designed in the Laboratory; its originality being the use of a counting technique instead of the classical multichannel analyzer one. The data acquisition and reduction procedures are presented here. A comprehensive evaluation of the global flow-field is in the scope of this paper. For that, the intra-blade flow field is described and the shock pattern is discussed. Furthermore, the experimental results are compared with both inviscid and viscous three-dimensional numerical simulations. The viscous computation is based on the Navier-Stokes solution using a mixing length turbulence model. The good agreement observed in this last case shows off the necessity of taking into account the viscous effects in a supersonic compressor flow calculation.

show abstract

Rotor wake characteristics of a transonic axial-flow fan

Cited by 28 publications

References 11 publications

Measurements of the Unsteady Flow Field Within the Stator Row of a Transonic Axial-Flow Fan: II — Results and Discussion

Measurements of the Unsteady Flow Field Within the Stator Row of a Transonic Axial-Flow Fan: II — Results and Discussion

Comparison of ω-Based Turbulence Models for Simulating Separated Flows in Transonic Compressor Cascades

Laser Two-Focus Anemometry Investigation of the Flow Field Within a Supersonic Axial Compressor Rotor

Contact Info

Product

Resources

About