Most boosting systems in internal combustion engines utilize “pulse turbocharging” to maximize the energy extraction by the turbine. An internal combustion engine with more than four cylinders has a significant overlap between the exhaust pulses which, unless isolated, can decrease the overall pulse energy and increase the engine pumping loss. Thus, it is advantageous to isolate a set of cylinders and introduce the exhaust gases into two or more turbine entries separately. There are two main types of multiple entry turbines depending on the method of flow division: the twin-entry and the double-entry turbine. In the twin-entry design, each inlet feeds the entire circumference of the rotor leading edge regardless of inlet conditions. In contrast, the double-entry design introduces the flow from each gas inlet into the rotor leading edge through two distinct sectors of the nozzle. This paper compares the performance of a twin and double-entry mixed flow turbine. The turbines were tested at Imperial College for a range of steady-state flow conditions under equal and unequal admission conditions. The performance of the turbines was then evaluated and compared to one another. Based on experimental data, a method to calculate the mass flow under unequal admission from the full admission maps was also developed and validated against the test results.

References

References
1.
Pischinger
,
F.
, and
Wunsche
,
A.
,
1977
, “
The Characteristic Behaviour of Radial Turbines and its Influence on the Turbocharging Process
,”
Proceedings of the Institution of Mechanical Engineers, 12th International Congress on Combustion Engines
, Tokyo,
Vol.
A
,
pp
.
545
568
.
2.
Dale
,
A.
, and
Watson
,
N.
,
1986
, ”
Vaneless Radial Turbocharger Turbine Performance
,”
Proceedings of the Institution of Mechanical Engineers, 3rd International Conference on Turbocharging and Turbochargers
,
Paper No. C110/86
.
3.
Baines
,
N. C.
, and
Lavy
,
M.
,
1990
, “
Flows in Vaned and Vaneless Stators of Radial Inflow Turbocharger
,”
Proceedings of the Institution of Mechanical Engineers, 4th International Conference on Turbochargers and Turbocharging
,
Paper No. C405/005
.
4.
Baines
,
N. C.
,
Hajilouy-Benisi
,
A.
, and
Yeo
,
J. H.
,
1994
, “
The Pulse Flow Performance and Modelling of Radial Inflow Turbines
,”
Proceedings of the Institution of Mechanical Engineers, 5th International Conference on Turbocharging and Turbochargers
,
Paper No. C484/006/94
.
5.
Capobianco
,
O. M.
, and
Gambarotta
,
A.
,
1993
, “
Performance of a Twin-Entry Automotive Turbocharger Turbine
,”
Proceedings of the ASME Turbo Expo
,
Cincinnati, OH, May 24–27, ASME Paper No. 93-ICE-2
.
6.
Aghaali
,
H.
, and
Hajilouy-Benisi
,
A.
,
2007
, “
Experimental and Theoretical Investigation of Twin-Entry Radial Inflow Gas Turbine With Unsymmetrical Volute Under Full and Partial Admission Conditions
,” Proceedings of the ASME Turbo Expo, Montreal, Canada, May 14–17,
ASME
Paper No. GT2007-27807
.10.1115/GT2007-27807
7.
Ghasemi
,
S.
,
Shirani
,
E.
, and
Hajilouy-Benisi
,
A.
,
2005
, “
Performance Prediction of Twin-Entry Turbocharger Turbine
,”
Iranian J. Sci. Technol.
,
29
,
pp
.
145
155
.
8.
Hajilouy-Benisi
,
A.
,
Rad
,
M.
, and
Shahosseini
,
M. R.
,
2009
, “
Flow and Performance Characteristics of Twin-Entry Radial Turbine Under Full and Extreme Partial Admission Conditions
,”
ASME J. Turbomach.
,
79
,
pp
.
1127
1143
.10.1007/s00419-008-0295-5
9.
Mitzumachi
,
N.
,
Yoshiki
,
D.
, and
Endoh
,
T. A.
,
1979
, “
A Study on Performance of Radial Turbine Under Unsteady Flow Conditions
,”
Rep. Inst. Ind. Sci.
,
28
,
pp
.
122
130
.
10.
Benson
,
R. S.
, and
Scrimshaw
,
K. H.
,
1965
, “
An Experimental Investigation of Non-Steady Flow In a Radial Turbine
,”
Proceedings of the Institution of Mechanical Engineers
,
180
, Part 3J,
Paper 23
.
11.
Wallace
,
F. J.
, and
Blair
,
G. P.
,
1965
, “
The Pulsating-Flow Performance of Inward Radial-Flow Turbines
,”
Proceedings of the ASME Turbo Expo
, Washington DC, February 28–March 4,
ASME Paper No. 65-GT-21
.
12.
Copeland
,
C.
,
Seiler
,
M.
, and
Martinez-Botas
,
R. F.
,
2011
, “
Comparison Between Steady and Unsteady Double-Entry Turbine Performance Using the Quasi-Steady Assumption
,”
ASME J. Turbomach.
,
133
, p.
031001
.10.1115/1.4000580
13.
Copeland
,
C.
,
2010
, “
The Evaluation of Steady and Pulsating Flow Performance of a Double-Entry Turbocharger Turbine
,”
Ph.D. thesis
,
Imperial College of Science, Technology, and Medicine, University of London
,
London, UK
.
14.
Copeland
,
C.
,
Martinez-Botas
,
R. M.
, and
Seiler
,
M.
2008
Unsteady Performance of a Double-Entry Turbocharger Turbine With Comparison to Steady-Flow Conditions
,” Proceedings of the ASME Turbo Expo, Berlin, Germany, June 9–13,
ASME
Paper No. GT2008-50827
10.1115/GT2008-50827.
15.
Copeland
,
C.
,
Newton
,
P.
,
Martinez-Botas
,
R. M.
, and
Seiler
,
M.
,
2010
, “
The Effect of Unequal Admission on the Performance and Loss Generation in a Double-Entry Turbocharger Turbine
,” Proceedings of the ASME Turbo Expo, Glasgow, Scotland, June 14–18,
ASME
Paper No. GT2010-22212
.10.1115/GT2010-22212
16.
Romagnoli
,
A.
,
2010
, “
Aerodynamic and Thermal Characterization of Turbocharger Turbines: Experimental and Computational Evaluation
,”
Ph.D. thesis
,
Imperial College of Science, Technology, and Medicine, University of London
,
London, UK
.
17.
Szymko
,
S.
,
McGlashan
,
N. R.
,
Martinez-Botas
,
R. F.
, and
Pullen
,
K. R.
,
2007
, “
The Development of a Dynamometer for Torque Measurement of Automotive Turbocharger Turbines
,”
Proc. Inst. Mech. Eng.
,
221
,
pp
.
225
239
.10.1243/09544070JAUTO401
18.
Szymko
,
S.
,
2006
, “
The Development of an Eddy Current Dynamometer for Evaluation of Steady and Pulsating Turbocharger Turbine Performance
,”
Ph.D. thesis
,
Imperial College of Science, Technology, and Medicine, University of London
,
London, UK
.
19.
Romagnoli
,
A.
,
Rajoo
,
S.
, and
Martinez-Botas
,
R. F.
,
2010
,
Turbine Performance Studies for Automotive Turbochargers Part One: Steady Analysis
,”
9th International Conference on Turbochargers and Turbocharging
,
London, May 19–20
.
20.
Rajoo
,
S.
,
2007
, “
Steady and Pulsating Performance of a Variable Geometry Mixed Flow Turbocharger Turbine
,”
Ph.D. thesis
,
Imperial College of Science, Technology, and Medicine, University of London
,
London, UK
.
21.
Abidat
,
M.
,
1991
, “
Design and Testing of a Highly Loaded Mixed Flow Turbine
,”
Ph.D. thesis
,
Imperial College of Science, Technology, and Medicine, University of London
,
London, UK
.
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