Heavy Vehicle Technologies Research Articles

Strategic transport fleet analysis of heavy goods vehicle technology for net-zero targets

This paper addresses the decarbonisation of the heavy-duty transport sector and develops a strategy towards net-zero greenhouse gas (GHG) emissions in heavy-goods vehicles (HGVs) by 2040. By conducting a literature review and a case study on the vehicle fleet of a large UK food and consumer goods retailer, the feasibilities of four alternative vehicle technologies are evaluated from environmental, economic, and technical perspectives. Socio-political factors and commercial readiness are also examined to capture non-technical criteria that influences decision-makers. Strategic analysis frameworks such as PEST-SWOT models were developed for liquefied natural gas, biomethane, electricity and hydrogen to allow a holistic comparison and identify their long-term deployment potential. Technology innovation is needed to address range and payload limitations of electric trucks, whereas government and industry support are essential for a material deployment of hydrogen in the 2030s. Given the UK government's plan to phase out new diesel HGVs by 2040, fleet operators should commence new vehicle trials by 2025 and replace a considerable amount of their lighter diesel trucks with zero-emission vehicles by 2030, and the remaining heavier truck fleet by 2035.

The Development of a “Pin-on-Twin” Scuffing Test to Evaluate Materials for Heavy-Duty Diesel Fuel Injectors*

In order to meet stricter emissions requirements, advanced heavy-duty diesel fuel injection systems will be required to operate at higher pressures and temperatures and in fuels that have poorer lubricity. Scuffing, as a mode of failure, severely limits injector life, and new materials and processes are required to resist scuffing in these more stringent operating conditions. Consequently, there is a need to test the ability of candidate fuel system materials to resist scuffing in fuel-lubricated environments. This paper describes a pin-on-twin reciprocating wear test in which a cylindrical specimen slides, under load, across two fixed, parallel cylindrical specimens that are perpendicular to the axis of the upper sliding specimen. Cylinders of annealed AISI 52100 were tested dry and lubricated by Jet A fuel and on-highway #2 diesel fuel. The friction force was found to give a reliable real-time determination of the onset of scuffing as verified by the morphology of the wear scar. The scar width and surface roughness profiles either did not reliably detect the onset or were difficult to carry out with this geometry. *Research sponsored by the U.S. Department of Energy, Assistant Secretary for Energy Efficiency and Renewable Energy, Office of Office of Freedom CAR and Heavy Vehicle Technologies, under contract DE-AC05-00OR22725 with UT-Battelle LLC. Review led by Roger Melley

Small-Channel Flow Boiling of One-Component Fluids and an Ethylene Glycol/Water Mixture*

Boiling heat transfer experiments were performed in a 2.98-mm inside-diameter horizontal tube with a two-component mixture of 50/50 ethylene glycol and water. The data were compared with existing results from three single-component fluids under similar boiling conditions. Boiling heat transfer in small channels with the single-component fluids exhibited a nucleation dominant region that is considerably more extensive than found in larger diameter tubes. Data for the 50/50 ethylene glycol/water mixture were similar in this regard to the single-component fluids; differences occurred with respect to heat transfer rates, extent of transition boiling, critical heat flux, and flow stability. Based on these data comparisons, we developed a concept for dividing flow boiling into its three regions. Using this division, we developed a new general correlation for the nucleation-dominant region based on Boiling and Weber numbers. The correlation is specific to nucleation-dominant flow boiling in small channels, and it provides good predictions of the data from all four fluids: Refrigerants 12 and 134a, water, and 50/50 ethylene glycol/water mixture. *Work supported by the U.S. Department of Energy, Offices of Heavy Vehicle Technologies and Ad vanced Automotive Technologies, under Contract W-31-109-Eng-38.

Bulk mean temperature in porous medium analysis

This work was supported by the post-doctoral fellowship program of Korea Science & Engineering Foundation (KOSEF) and partially supported by the U.S. Department of Energy, Office of Science-Division of Materials Science and Engineering and Office of Transportation Technologies-Office of Heavy Vehicle Technologies (W-31-109-Eng-38).

CAFE compliance by light trucks: economic impacts of clean diesel engine

With the popularity of light trucks increasing in the United States, their share of the US light vehicle market had doubled between 1980 and 1996, climbing from 20 to 40%. By 1996, annual energy consumption for light trucks had risen to 5.97×10 15 Btu [5.97 quadrillion Btu, or “quad,” or 6.30×10 18 joule (J)], compared to 7.94 quad (8.38×10 18 J) for cars. In recent years (since 1995), the fuel economy of US - manufactured light trucks (almost 99% of which use gasoline engines) has been below the Corporate Average Fuel Economy (CAFE) standards. This paper analyzes a strategy to reduce the CAFE shortfalls by adopting the new, highly energy-efficient clean diesel engine. Research on such engines has been funded by the US Department of Energy, Office of Heavy Vehicle Technologies, under its Light Truck Clean Diesel Engine Program. A clean diesel engine market penetration trajectory is developed, representing an industry response to meet the CAFE standards. Whether the engine will be produced inside the country or imported remains uncertain, so two cases are defined. Values of exports/imports of clean diesel engines/trucks under these cases are estimated. The macroeconomic benefits are estimated by using a model of the US economy developed by Standard & Poor's Data Resources, Inc. On the basis of gains in the gross domestic product projected under the alternative cases, domestic production of the clean diesel engine is favored over importing it.