Study of Transit Bus Duty Cycle and its Influence on Fuel Economy and Emissions of Diesel-Electric Hybrids

A dynamic programming optimization algorithm has been applied on a transit bus model in MATLAB in order to assess the fuel economy improvement potential by implementing a hydraulic hybrid powertrain system. The numerical model parameters have been calibrated using experimental data obtained on a Belgrade?s public transport bus. This experiment also provided the representative driving cycle on which to conduct simulation analyses. Various functional parameters of a hydraulic hybrid system have been evaluated for obtaining the best possible fuel economy. Dynamic programming optimization runs have been completed for various hydraulic accumulator sizes, preload values and accumulator foam quantities. It has been shown that a fuel economy improvement of 28% can be achieved by implementing such a system.

Download Full-text

Transit Bus Fuel Economy and Performance Simulation

10.4271/841691 ◽

1984 ◽

Cited By ~ 2

Author(s):

Russell W. Zub

Keyword(s):

Fuel Economy ◽

Performance Simulation ◽

And Performance ◽

Transit Bus

Download Full-text

Correlation Analysis of Duty Cycle Effects on Exhaust Emissions and Fuel Economy

Journal of the Transportation Research Forum ◽

10.5399/osu/jtrf.52.1.4136 ◽

2013 ◽

Cited By ~ 1

Author(s):

Jun Tu ◽

W. Scott Wayne ◽

Mario G. Perhinschi

Keyword(s):

Regression Analysis ◽

Correlation Analysis ◽

Detailed Analysis ◽

Fuel Economy ◽

Duty Cycle ◽

Drive Cycle ◽

Average Speed ◽

Emissions Modeling ◽

Specific Emissions ◽

Linear Correlations

Correlation analysis was performed to investigate the effects of drive cycle characteristics on distance-specific emissions (g/mile) and fuel economy (mpg) and consequently determine the most influential cycle metrics for modeling. A detailed analysis of linear and non-linear correlations was performed among cycle metrics to avoid collinearity and reduce the number of variables. The order of importance of the selected cycle metrics was determined. Results show that average speed with idle, number of stops per mile, percentage idle, and kinetic intensity were the most important cycle metrics affecting emissions and fuel economy. Preliminary regression analysis reinforced their importance for emissions modeling purposes.

Download Full-text

Duty Cycle Operation as a Possibility to Enhance the Fuel Economy of an SI Engine at Part Load

10.4271/960229 ◽

1996 ◽

Cited By ~ 3

Author(s):

Martin Ender ◽

Philipp Dietrich

Keyword(s):

Fuel Economy ◽

Duty Cycle ◽

Si Engine ◽

Part Load

Download Full-text

Impact of Auxiliary Loads on Fuel Economy and Emissions in Transit Bus Applications

10.4271/2012-01-1028 ◽

2012 ◽

Cited By ~ 3

Author(s):

Rachel L. Muncrief ◽

Miguel Cruz ◽

Henry Ng ◽

Michael Harold

Keyword(s):

Fuel Economy ◽

In Transit ◽

Transit Bus

Download Full-text

Two-photon excitation microscopy in cellular biophysics

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100136684 ◽

1995 ◽

Vol 53 ◽

pp. 62-63

Author(s):

David W. Piston ◽

Brian D. Bennett ◽

Robert G. Summers

Keyword(s):

Confocal Microscopy ◽

Laser Beam ◽

Duty Cycle ◽

Excited Electronic State ◽

Input Power ◽

Two Photon ◽

Simultaneous Absorption ◽

Photon Excitation ◽

Very High ◽

Two Photon Excitation

Two-photon excitation microscopy (TPEM) provides attractive advantages over confocal microscopy for three-dimensionally resolved fluorescence imaging and photochemistry. Two-photon excitation arises from the simultaneous absorption of two photons in a single quantitized event whose probability is proportional to the square of the instantaneous intensity. For example, two red photons can cause the transition to an excited electronic state normally reached by absorption in the ultraviolet. In practice, two-photon excitation is made possible by the very high local instantaneous intensity provided by a combination of diffraction-limited focusing of a single laser beam in the microscope and the temporal concentration of 100 femtosecond pulses generated by a mode-locked laser. Resultant peak excitation intensities are 106 times greater than the CW intensities used in confocal microscopy, but the pulse duty cycle of 10-5 maintains the average input power on the order of 10 mW, only slightly greater than the power normally used in confocal microscopy.

Download Full-text