Applications

The objective of this work is to develop a comprehensive heat transfer and thermal analysis methodology oriented specifically to the design requirements of insulated diesel engines. The methodology is to make possible a quantitative analysis of the low heat rejection (LHR) engine concept, including the determination of performance improvements, identification of design strategies for optimum engine insulation, and a detailed characterization of the thermal environment in which structural materials and lubricants have to exist.

Heat transfer is the controlling process in LHR and insulated engines, influencing engine performance; thermal loads; required material properties and application method; and lubrication, friction and wear. The engineering analysis of LHR engines must consider all of these interrelated effects to be truly applicable. The previous methods available are deficient in the physical description of the heat transfer processes, and moreover they cannot be used for a complete analysis of all of the above effects because they are not fully integrated to represent mutual interactions of all of the contributing engine processes.

In view of these technical issues, the ITI work has been structured to address the areas in which previous design analysis methods are deficient. It is to advance the state of the art so that significant design issues related to performance, materials and tribology can be addressed and resolved. To achieve these objectives, a number of closely related program elements or task areas were carried out:

• development of spatially and temporally resolved convection and radiation heat transfer submodels,

• analysis of engine structural heat transfer under steady-state conditions,

• analysis of structural heat transfer during cyclic thermal transients and during rapid engine transients (thermal shock),

• baseline cooled engine experiments and calibration of heat transfer models,

• insulated engine experiments and validation of model predictions,

• analysis of insulated engine issues.

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