Numerical Analysis of a Centrifugal Fan for Improved Performance using Splitter Vanes
The flow field in a centrifugal fan is highly complex
with flow reversal taking place on the suction side of impeller and
diffuser vanes. Generally performance of the centrifugal fan could be
enhanced by judiciously introducing splitter vanes so as to improve
the diffusion process. An extensive numerical whole field analysis on
the effect of splitter vanes placed in discrete regions of suspected
separation points is possible using CFD. This paper examines the
effect of splitter vanes corresponding to various geometrical
locations on the impeller and diffuser. The analysis shows that the
splitter vanes located near the diffuser exit improves the static
pressure recovery across the diffusing domain to a larger extent. Also
it is found that splitter vanes located at the impeller trailing edge and
diffuser leading edge at the mid-span of the circumferential distance
between the blades show a marginal improvement in the static
pressure recovery across the fan. However, splitters provided near to
the suction side of the impeller trailing edge (25% of the
circumferential gap between the impeller blades towards the suction
side), adversely affect the static pressure recovery of the fan.
[1] Ogawa, T. & Gopalakrishnan, G., "Flow Calculation in a Centrifugal
Impeller by the Method of Singularities and its Experimental
Verification," Proc. Of the Seventh National Conference on Fluid Power
and Fluid Mechanics, 1977, Baroda, India.
[2] Ogawa, T. & Gopalakrishnan, G., "Use of Splitter Vanes in Centrifugal
Compressor Impellers," Proc. Of the Eighth Canadian Congress of
Applied Mechanics, 1981, Moncton, Canada
[3] Bhargava, R.K. & Gopalakrishnan, G., 1978, "Optimising Splitter Vane
Locations Using the Method of Singularities," Proc. Of the First
International Conference on Centrifugal Compressor Technology, 1978,
I. I. T. Madras, India
[4] Fabri, J., "Flow Distribution in a Radial Impeller with Splitter Vanes,"
Proc. Of the First International Conference on Centrifugal Compressor
Technology, 1978, I.I.T. Madras, India
[5] Millour, V., "3D Flow Computations in a Centrifugal Compressor with
Splitter Blade Including Viscous Effect Simulation," 16th Congress,
International Council of Aeronautical Societies, Volume 1, 1988, pp.
842 - 847
[6] Fradin, C., "Investigation of the Three Dimensional Flow near the Exit
of Two Backswept Transonic Centrifugal Impellers," Proc. of the Eighth
International Symposium in Air Breathing Engines, 1987, pp. 149 -155
[7] Gui, L., Gu, C., Chang, H., "Influences of Splitter Blades on the
Centrifugal Fan Performances," 1989, ASME paper 89-GT-33
[8] Kergourlay, G., Younsi, M., Bakir, F. and Rey, R., Influence of Splitter
Blades on the Flow Field of a Centrifugal Pump: Test-Analysis
Comparison, International Journal of Rotating Machinery, Volume 2007,
Article ID 85024, 13 pages.
[9] Teipel I. and Wiedermann, A. "Computation of Flowfields in
Centrifugal Compressor Diffusers with Splitter Vanes", The
International Gas Turbine Congress, 1987, (2) pp. II-311- II-317.
[10] Oana, M., Kawamoto, O., Ohtani, H., Yamamoto, Y., "Approach to
High Performance Transonic Centrifugal Compressor," AIAA paper
2002-3536
[11] J. McGlumphy "Numerical Investigation of Subsonic Axial-Flow
Tandem Airfoils for a Core Compressor Rotor", PhD Dissertation, 2008,
Mechanical Engineering Department Virginia Tech.
[12] Fatsis, A., Pierret, S. and Van den Braembussche, R., "Threedimensional
unsteady flow and forces in centrifugal impellers with
circumferential distortion of the outlet static pressure", Journal of
Turbomachinery, 1997, 119, pp 94-102.
[13] Sorokes, J. M., Borer, J.C. and Koch, J.M., 1998, "Investigation of the
circumferential static pressure non-uniformity caused by centrifugal
compressor discharge volute", 98 GT 326, International Gas Turbine &
Aeroengine Congress & Exhibition, Stockholm, 1998, Sweden.
[14] Hillewaert, K. and Van den Braembussche, R.A., "Numerical simulation
of impeller-volute interaction in centrifugal compressors", Journal of
Turbomachinery, 121, 1999, pp 603-608.
[15] Shi, F. and Tsukamoto, H., "Numerical Study of Pressure Fluctuations
Caused by Impeller-Diffuser Interaction in a Diffuser Pump Stage",
Transactions of the ASME, 9, Vol. 123, 2001, pp. 466 - 474.
[16] Meakhail, T. and Park, S.O., "A Study of Impeller-Diffuser-Volute
Interaction in a Centrifugal Fan", ASME Journal of Turbomachinery,
127, 2005, pp. 84 - 90.
[17] Fluent 6.3, Fluent Inc., 2006.
[18] Patankar, S.V., Numerical Heat Transfer and Fluid Flow, Tailor and
Francis, (1980), pp. 90-92.
[1] Ogawa, T. & Gopalakrishnan, G., "Flow Calculation in a Centrifugal
Impeller by the Method of Singularities and its Experimental
Verification," Proc. Of the Seventh National Conference on Fluid Power
and Fluid Mechanics, 1977, Baroda, India.
[2] Ogawa, T. & Gopalakrishnan, G., "Use of Splitter Vanes in Centrifugal
Compressor Impellers," Proc. Of the Eighth Canadian Congress of
Applied Mechanics, 1981, Moncton, Canada
[3] Bhargava, R.K. & Gopalakrishnan, G., 1978, "Optimising Splitter Vane
Locations Using the Method of Singularities," Proc. Of the First
International Conference on Centrifugal Compressor Technology, 1978,
I. I. T. Madras, India
[4] Fabri, J., "Flow Distribution in a Radial Impeller with Splitter Vanes,"
Proc. Of the First International Conference on Centrifugal Compressor
Technology, 1978, I.I.T. Madras, India
[5] Millour, V., "3D Flow Computations in a Centrifugal Compressor with
Splitter Blade Including Viscous Effect Simulation," 16th Congress,
International Council of Aeronautical Societies, Volume 1, 1988, pp.
842 - 847
[6] Fradin, C., "Investigation of the Three Dimensional Flow near the Exit
of Two Backswept Transonic Centrifugal Impellers," Proc. of the Eighth
International Symposium in Air Breathing Engines, 1987, pp. 149 -155
[7] Gui, L., Gu, C., Chang, H., "Influences of Splitter Blades on the
Centrifugal Fan Performances," 1989, ASME paper 89-GT-33
[8] Kergourlay, G., Younsi, M., Bakir, F. and Rey, R., Influence of Splitter
Blades on the Flow Field of a Centrifugal Pump: Test-Analysis
Comparison, International Journal of Rotating Machinery, Volume 2007,
Article ID 85024, 13 pages.
[9] Teipel I. and Wiedermann, A. "Computation of Flowfields in
Centrifugal Compressor Diffusers with Splitter Vanes", The
International Gas Turbine Congress, 1987, (2) pp. II-311- II-317.
[10] Oana, M., Kawamoto, O., Ohtani, H., Yamamoto, Y., "Approach to
High Performance Transonic Centrifugal Compressor," AIAA paper
2002-3536
[11] J. McGlumphy "Numerical Investigation of Subsonic Axial-Flow
Tandem Airfoils for a Core Compressor Rotor", PhD Dissertation, 2008,
Mechanical Engineering Department Virginia Tech.
[12] Fatsis, A., Pierret, S. and Van den Braembussche, R., "Threedimensional
unsteady flow and forces in centrifugal impellers with
circumferential distortion of the outlet static pressure", Journal of
Turbomachinery, 1997, 119, pp 94-102.
[13] Sorokes, J. M., Borer, J.C. and Koch, J.M., 1998, "Investigation of the
circumferential static pressure non-uniformity caused by centrifugal
compressor discharge volute", 98 GT 326, International Gas Turbine &
Aeroengine Congress & Exhibition, Stockholm, 1998, Sweden.
[14] Hillewaert, K. and Van den Braembussche, R.A., "Numerical simulation
of impeller-volute interaction in centrifugal compressors", Journal of
Turbomachinery, 121, 1999, pp 603-608.
[15] Shi, F. and Tsukamoto, H., "Numerical Study of Pressure Fluctuations
Caused by Impeller-Diffuser Interaction in a Diffuser Pump Stage",
Transactions of the ASME, 9, Vol. 123, 2001, pp. 466 - 474.
[16] Meakhail, T. and Park, S.O., "A Study of Impeller-Diffuser-Volute
Interaction in a Centrifugal Fan", ASME Journal of Turbomachinery,
127, 2005, pp. 84 - 90.
[17] Fluent 6.3, Fluent Inc., 2006.
[18] Patankar, S.V., Numerical Heat Transfer and Fluid Flow, Tailor and
Francis, (1980), pp. 90-92.
@article{"International Journal of Mechanical, Industrial and Aerospace Sciences:50562", author = "N. Yagnesh Sharma and K. Vasudeva Karanth", title = "Numerical Analysis of a Centrifugal Fan for Improved Performance using Splitter Vanes", abstract = "The flow field in a centrifugal fan is highly complex
with flow reversal taking place on the suction side of impeller and
diffuser vanes. Generally performance of the centrifugal fan could be
enhanced by judiciously introducing splitter vanes so as to improve
the diffusion process. An extensive numerical whole field analysis on
the effect of splitter vanes placed in discrete regions of suspected
separation points is possible using CFD. This paper examines the
effect of splitter vanes corresponding to various geometrical
locations on the impeller and diffuser. The analysis shows that the
splitter vanes located near the diffuser exit improves the static
pressure recovery across the diffusing domain to a larger extent. Also
it is found that splitter vanes located at the impeller trailing edge and
diffuser leading edge at the mid-span of the circumferential distance
between the blades show a marginal improvement in the static
pressure recovery across the fan. However, splitters provided near to
the suction side of the impeller trailing edge (25% of the
circumferential gap between the impeller blades towards the suction
side), adversely affect the static pressure recovery of the fan.", keywords = "Splitter vanes, Flow separation, Sliding mesh,Unsteady analysis, Recirculation zone, Jets and wakes.", volume = "3", number = "12", pages = "1449-7", }
