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CHAPTER 5 Power Efficiencies and Measurement

Published by the American Society of Agricultural and Biological Engineers, St. Joseph, Michigan www.asabe.org

Citation:  Chapter 5, Pages 75-110 (doi:10.13031/2013.24140) in Chapter 5 in Engine and Tractor Power, 4th edition. St. Joseph, Michigan: ASAE. . Copyright 2015 American Society of Agricultural and Biological Engineers, St. Joseph, Mich.
Authors:   Carroll E. Goering and Alan C. Hansen
Keywords:   Torque and Power, Power Adjectives, Mean Effective Pressures, Power Efficiencies, Specific Fuel Consumption, Volumetric Efficiency, Engine Governors and Governed Engine Performance, Engine Performance Simulator, Dynamometers for Measuring Engine Power, Standardized Tractor Tests

Engines are designed to convert fuel energy into useful mechanical power, but typical engines convert less than half of the fuel energy. The remainder is lost in the conversion processes. Various efficiency terms have developed as aids for comparing energy-converting abilities of different engines. Learning these terms will help you to compare and discuss engines intelligently. To give an intelligent discussion of the performance of a tractor engine, you must also know and understand the terms high idle, governor's maximum, governor control, load control, governor regulation, and torque reserve. These terms will be explained in Section 5.8 of this chapter. The measurement of power efficiencies can be accomplished with a number of devices and techniques, as described in Section 5.10 of this chapter. You will learn to interpret and use a tractor test report in Section 5.11.

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