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The paper presents results of an organized and extensive wind tunnel test-program, complemented by flow visualization and full-scale road tests, aimed at assessing the effectiveness of a boundary-layer control procedure for the drag reduction of a cube-van. Wind tunnel results, obtained using 1/6 scale model, at a subcritical Reynolds number of 105, suggest that tripping of the boundary-layer using fences reduce the pressure drag coefficient. The entirely passive character of the procedure is quite attractive from the economic consideration as well as the ease of implementation. The road tests with a full-size cube-van substantiated the trends indicated by the fence data; although the actual drag reduction observed was lower (yet quite significant, 16.6%) than that predicted by the wind tunnel tests. This may be attribute to a wide variety of factors including the differences in the geometry and test conditions. Fuel consumption results also substantiated the drag reduction trend.

Heavy-duty diesel trucking is responsible for 25%-30% of the road transportation CO2 emissions in North America. Retrofitting class-8 trucks with a complementary hydrogen fuelling system makes it possible to co-combust hydrogen and diesel in the existing internal combustion engine (ICE), thus minimizing the costs associated with switching to non-ICE platforms and reducing the barrier for the implementation of low-carbon gaseous fuels such as hydrogen. This retrofitting approach is evaluated based on the exhaust emissions of a converted truck with several thousand kilometres of road data. The heavy-duty truck used here was retrofitted with an air-intake hydrogen injection system, onboard hydrogen storage tanks, and a proprietary hydrogen controller enabling it to operate in hydrogen-diesel co-combustion (HDC) mode.