The turbocharger and turbocharging have been the
inherent component of diesel engines, so that critical parameters of
such engines, as BSFC (Brake Specific Fuel Consumption) or
thermal efficiency, fuel consumption, BMEP (Brake Mean Effective
Pressure), the power density output and emission level have been
improved extensively. In general, the turbocharger can be considered
as the most complex component of diesel engines, because it has
closely interrelated turbomachinery concepts of the turbines and the
compressors to thermodynamic fundamentals of internal combustion
engines and stress analysis of all components.
In this paper, a waste gate for a conventional single stage radial
turbine is investigated by consideration of turbochargers operation
constrains and engine operation conditions, without any detail
designs in the turbine and the compressor. Amount of opening waste
gate which extended between the ranges of full opened and closed
valve, is demonstrated by limiting compressor boost pressure ratio.
Obtaining of an optimum point by regard above mentioned items is
surveyed by three linked meanline modeling programs together
which consist of Turbomatch®, Compal®, Rital® madules in concepts
 H. Sun, et al. “Challenges and Opportunities in Turbocharger
Technology for Future Diesel LTC” GPC2009 Global Powertrain
Congress, Troy, MI, 2009.
 S. Arnold, “Single Sequential Turbocharger: A New Boosting Concept
for Ultra-Low Emission Diesel Engines” Int. J. Engines 1(1):232-239,
 N. C. Baines “Radial and mixed flow turbine options for high boost
turbochargers” 7th International Conference on Turbochargers and
Turbocharging, London, UK, 2002.
 D. Japikse, Cenrtifugal Compressor Design and Performance, Concepts
ETI, Inc., Wilder, VT, 1996, Ch. 6.
 H. Moustapha, M. F. Zelesky, N. C. Baines, and D. Japikse, Axial and
Radial Turbines, Concepts ETI, Wilder, Vermont, Inc. 2003, Ch. 9.
 N. C. Baines, “The Turbocharging Challenge”, 2006, Concepts NREC,
Wilder, VT, USA.
 N. C. Baines, Fundamental of Turbocharging, Concepts NREC, Wilder,
VT. 2005, Ch. 1 and 5.