The performance and detailed flow characteristics of a high pressure ratio mixed flow turbine has been investigated under steady and pulsating flow conditions. The rotor has been designed to have a nominal constant incidence (based on free vortex flow in the volute) and it is for use in an automotive high speed diesel turbocharger. The results indicated a departure from the quasi-steady analysis commonly used in turbocharger turbine design. The pulsations from the engine have been followed through the inlet pipe and around the volute; the pulse has been shown to propagate close to the speed of sound and not according to the bulk flow velocity as stated by some researchers. The flow entering and exiting the blades has been quantified by a laser Doppler velocimetry system. The measurements were performed at a plane 3.0 mm ahead of the rotor leading edge and 9.5 mm behind the rotor trailing edge. The turbine test conditions corresponded to the peak efficiency point at 29,400 and 41,300 rpm. The results were resolved in a blade-to-blade sense to examine in greater detail the nature of the flow at turbocharger representative conditions. A correlation between the combined effects of incidence and exit flow angle with the isentropic efficiency has been shown. The unsteady flow characteristics have been investigated at two flow pulse frequencies, corresponding to internal combustion engine speeds of 1600 and 2400 rpm. Four measurement planes have been investigated: one in the pipe feeding the volute, two in the volute (40 deg and 130 deg downstream of the tongue) and one at the exit of the turbine. The pulse propagation at these planes has been investigated; the effect of the different planes on the evaluation of the unsteady isentropic efficiency is shown to be significant. Overall, the unsteady performance efficiency results indicated a significant departure from the corresponding steady performance, in accordance with the inlet and exit flow measurements.

Issue Section:
Technical Papers
Keywords:
gas turbines, pulsatile flow, rotors, velocity measurement, laser Doppler anemometry, pipe flow, flow instability
Topics:
Flow (Dynamics), Rotors, Turbines, Blades, Design
1.
Arcoumanis, C., Hakeem, I., Khezzar, L., Martinez-Botas, R. F., and Baines, N. C., 1995, “Performance of a Mixed Flow Turbocharger Turbine Under Pulsating Flow Conditions,” ASME Paper No. 95-GT-210.
2.
Abidat
,
M.
,
Chen
,
H.
,
Baines
,
N. C.
, and
Firth
,
M. R.
,
1992
, “
Design of a Highly Loaded Mixed Flow Turbine
,”
Proc. Inst. Mech. Eng., J. Power Energy
,
206
, pp.
95
–
107
.
3.
Baines, N. C., Wallace, F. J., and Whitfield, A., 1978, “Computer Aided Design of Mixed Flow Turbines for Turbocharger,” ASME Paper No. 78-GT-191.
4.
Chen
,
H.
,
Hakeem
,
I.
, and
Martinez-Botas
,
R. F.
,
1996
, “
Modelling of a Turbocharger Turbine Under Pulsating Inlet Conditions
,”
Proc. Inst. Mech. Eng., Part A: J. Power Energy
,
210
, pp.
397
–
408
.
5.
Chou, C., and Gibbs, C. A., 1989, “The Design and Testing of a Mixed-Flow Turbine for Turbochargers,” SAE Paper No. 890644.
6.
Wallace, F. J., and Pasha, S. G. A., 1972, “Design, Construction and Testing of a Mixed-Flow Turbine,” The 2nd International JSME Symposium, Fluid Machinery and Fluids, Tokyo.
7.
Arcoumanis
,
C.
,
Martinez-Botas
,
R. F.
,
Nouri
,
J. M.
, and
Su
,
C. C.
,
1997
, “
Performance and Exit Flow Characteristics of Mixed Flow Turbines
,”
Int. J. Rotating Mach.
,
3
, No.
4
, pp.
277
–
293
.
8.
Benisek, E., 1998, “Experimental and Analytical Investigation of the Flow Field of a Turbocharger Turbine,” IMechE, Paper No. C554/027/98.
9.
Kreuz-Ilhi, T., Filsinger, D., Schulz, A., and Wittig, S., 1999, “Numerical and Experimental Study on the Unsteady Flow Field and Vibration of Radial Inflow Turbines,” ASME Paper No. 99-GT-341.
10.
Baines, N. C., and Yeo, J. H., 1991, “Flow in a Radial Turbine Under Equal and Partial Admission,” IMechE Paper No. C423/002.
11.
Winterbone, D. E., Nikpour, B., and Alexander, G. L., 1990, “Measurement of the Performance of a Radial Inflow Turbine in Conditional Steady and Unsteady Flow,” IMechE Paper No. C405/015.
12.
Karamanis, N., Martinez-Botas, R. F., and Su, C. C., 1999, “Detailed Flow Measurements at the Exit of a Mixed Flow Turbine,” ASME Paper No. 99-GT-342.
13.
Dale, A., and Watson, N., 1986, “Vaneless Radial Turbocharger Turbine Performance,” IMechE Paper C110/86.
14.
Murugan, D. M., Tabakoff, W., and Hamed, A., 1996, “Three-Dimensional Flow Field Measurements Using LDV in the Exit Region of a Radial Inflow Turbine,” Exp. Fluids, 20.
15.
Kosuge
,
H.
,
Yamanaka
,
N.
,
Ariga
,
I.
, and
Watanabe
,
I.
,
1976
, “
Performance of Radial Flow Turbines Under Pulsating Flow Conditions
,”
ASME J. Eng. Power
,
98
, pp.
53
–
59
.
16.
Dale, A., Watson, N., and Cole, A. C., 1988, “The Development of a Turbocharger Turbine Test Facility,” IMechE, Seminar on Experimental Methods in Engine Research and Development.
17.
Baines, N. C., Hajilouy-Benisi, A., and Yeo, J. H., 1994, “The Pulse Flow Performance and Modelling of Radial Inflow Turbines,” IMechE Paper No. C405/017.
18.
Mollenhauer, K., 1967, “Measurement of Instantaneous Gas Temperatures for Determination of the Exhaust Gas Energy of a Supercharged Diesel Engine,” SAE Paper No. 67929.
19.
Benson, R. S., 1974, “Non-Steady Flow in a Turbocharger Nozzleless Radial Gas Turbine,” SAE Paper No. 740739.
20.
Capobianco, M., Garambarotta, A., and Cipolla, G., 1989, “Influence of the Pulsating Flow Operation on the Turbine Characteristics of a Small Internal Combustion Engine Turbocharger,” IMechE Paper No. C372/019.
21.
Winterbone, D. E., Nikpour, B., and Frost, H., 1991, “A Contribution to the Understanding of Turbocharger Turbine Performance in Pulsating Flow,” IMechE Paper No. C433/011.
22.
Hajilouy-Benisi, A., and Baines, N. C., 1992, “Small High Speed Radial Inflow Turbine,” Int. Conf. Eng. Appl. Mech.
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