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A description of the development of a single cylinder test facility is presented, being based on a production 4-cylinder DI Diesel engine and designed to allow study of the emissions characteristics over a very wide range of operating conditions. The objective was to establish how engine out NO x emissions can be reduced to the estimated levels required by the next emissions target "Euro 6" and thus be able to apply the findings to the original 4-cylinder engine and minimise the requirement for currently immature NOx after treatment. It has been proposed that further reduction in compression ratio beyond current levels would be beneficial to engine out emissions and specific power, and could be facilitated by developments in cold start technology. The results of a study using this single cylinder facility to evaluate the effect of reducing compression ratio from 18.4 to 16.0 are presented. It was found that, although there was a small CO and HC penalty, either reducing the compression ratio or retarding the injection timing greatly reduced NOx and soot emissions when both premixed and diffusion-combustion phases were present. This effect was less significant when the combustion was solely premixed.

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This paper presents a family of methods for comparing compact heat transfer surface configurations. It is shown how measures for the relative values of required hydraulic diameter, frontal area, total volume, pumping power, and number of transfer units for different surfaces can be derived and displayed, when any two of the above five parameters are held constant. A wide range of comparisons that are independent of the particular duty can be simply made. A further development allowing comparisons, where three of the five parameters are fixed, yields very clear and compact indications of the relative merits of different surfaces.