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To gain high efficiencies and long lifetimes, polymer electrolyte membrane fuel cell systems require precise control of the relative humidity of the cathode supply air. This is usually accomplished with membrane humidifiers. These are passive components that use the humidity of the cathode exhaust air to humidify the supply air. Due to the passive design, controllability is achieved via a bypass. To avoid the use of humidity sensors, map-based control strategies are possible. Such map-based control requires deep insights into the humidifier behavior in all possible thermodynamic operating states, including various water loads. This paper focuses on typical operating conditions of heavy-duty application at high load, specifically on the occurrence of liquid water in the cathode exhaust stream, which has not been sufficiently investigated in the literature yet. In order to simulate these conditions, we built a test rig with an optically accessible single-channel set-up.

The objective of the project was to evaluate the energy efficiency of a hybrid electric tractor-semi-trailer combination prototype. The prototype was developed for log hauling application by integrating an existing tractor with an electric semi-trailer to improve fuel consumption and reduce greenhouse gas emissions. One of the conventional axles of the quad axle semi-trailer was replaced with a drive axle powered by an electric motor. Tests were conducted on a 105 km test route with a maximum difference in elevation of 355 m, including a hilly section with a length of 89 km. The results indicated fuel savings ranging from 10.5% to 14% per test run, with an average fuel savings of 12% when the electric drive axle was engaged. The hybrid electric tractor semi-trailer consumed 17.5% less fuel up-hill and 9.4% less down-hill. Throughout each test run, the battery’s state of charge fluctuated, averaging between 88% at the start and 52% at the end.

Abstract Engine brakes are more effective in braking a heavy-duty vehicle during deceleration compared to the traditional clutch-brake system. Therefore, commercial vehicle OEM’s along with regulations, demand the acclimatizing of engine brake (EB) system. To achieve this, it is equally important to adopt to variable valve actuation dynamic valvetrain (VT) system. To help develop these systems, Model Based Product Development approach is used primarily at Eaton. In current work, the effect of valve lash sensitivity on EB performance and VT dynamics is studied using multi physics GT-SUITE models. This helps to understand the impact of lash on valve lift opening, lift loss and overall VT system compliance. In addition to above VT dynamics, its effect on EB power is also studied. This is done using a medium duty 6-cylinder GT-POWER engine model developed from Fast Response Model (FRM) database.

A power steering system is a component that helps the heavy-duty operator to move easily the vehicle by the hydraulic pump providing the fluid pressure and facilitating adequate operation. Some failures in the power steering system are due to external and internal factors that can reduce its life. The external factor could be identified by ocular inspection but normally to internal failures is necessary to use a hydraulic pressure flow meter. However, with this device is impossible to detect failures by the lubricant selected. This work aims to investigate the causes of power steering system seizure by using the tribological wear examination process and the lubricant characterization under some actual operation conditions.

Vehicle electrification has emerged as a pivotal area of research across diverse industries. When applied to heavy-duty vehicles (i.e., school buses), it presents a unique opportunity for the automotive sector to lead sustainability efforts. Beyond energy savings, the electrification of school buses offers advantages such as improved children's health, reduced greenhouse gas emissions, and enhanced green vehicle routing, inspiring broader adoption of eco-friendly practices. This study primarily aims to analyze the energy-saving effects and economic viability resulting from the electrification of existing school bus routes. Specifically, the research examines the drive cycles of operational bus routes and evaluates the energy demand and cost implications associated with transitioning from conventional buses (diesel buses) to electric buses or other alternative powertrains for fleet operations.

Transit agencies globally have been investing in more battery electric buses (BEB) in an effort to combat growing negative externalities stemming from the use of traditional petrochemicals fuels in combustion vehicles. These buses use new battery technologies to cut carbon pollution and promote cleaner, faster, and safer rides. As new electrification technologies continue to penetrate the bus transit market, there is a continuous need to evaluate the safety and performance of these battery systems. To meet the need of ensuring the safety and performance of battery technologies in transit buses, regulations and standards have been established and are continuously refined to prescribe best testing and industry practices. In a joint research effort between The Ohio State University and the Federal Transit Administration (FTA), this paper details the current state of battery standards and regulations and how these standards and regulations tie back to battery failure modes and effects.

Combustion in conventional and advanced diesel engines is an intricate process that encompasses interaction among fuel injection, fuel-air mixing, combustion, heat transfer, and engine geometry. Manipulation of fuel injection strategies has been recognized as a promising approach for optimizing diesel engine combustion. Although numerous studies have investigated this topic, the underlying physics behind flame interactions from multiple fuel injections, spray-flame-wall interaction and their effects on reaction zones, and NOx/soot emissions are still not well understood. To this end, a computational fluid dynamics (CFD) study is performed to investigate the effects of pilot and post injections on in-cylinder combustion process and emissions (NOx and soot) formation in a heavy-duty (HD) diesel engine.

Catalyst heating operation in compression-ignition engines is critical to ensure rapid light-off of exhaust catalysts during cold-start. This is typically achieved by using late post injections for increased exhaust enthalpy, which retardability is constrained by acceptable CO and unburned hydrocarbons emissions, since they are directly emitted through the tailpipe due to the inactivity of the oxidation catalyst at these conditions. Post-injection retardability has shown to be affected by the cetane number of the fuel [SAE 2022-01-0483], but it is unclear how other fuel properties may affect the ability to retard the combustion. This study aims to understand the impact of the distillation characteristics of the fuel on the performance of catalyst heating operation and on post-injection retardability.

The imperative for sustainability has spurred innovation across industries with a growing emphasis on minimizing environmental impact. In the transportation sector, optimizing engine lubricants emerges as a crucial avenue for achieving sustainable performance as engine oil is the primary lubricants waste stream. Re-Refined Base Oil (RRBO) presents a compelling solution, offering a sustainable alternative to conventional base oils. By reclaiming and recycling used oil, RRBO not only minimizes waste but also embodies the ethos of circularity, promoting resource efficiency and environmental stewardship. This study presents the collaborative efforts between an Indian Automotive OEM and key Lubricant Technology Partner towards the development of engine oil utilizing Re-Refined Base Oil (RRBO) for automotive applications.

With all the environmental concern of diesel fuelled vehicle, it is a formidable challenge to phase out them completely specifically from Heavy duty application. Most pragmatic solution lies in solutions which improves the fuel economy and reduce the carbon emission of existing diesel fuelled vehicle fleet and have economical & feasible for vast geographical extent of country. With implementation of BS VI emission norms across country from April 2020, supply of BS VI complied diesel fuel started and BS VI complied vehicles with upgraded engine technologies and after treatment devices have started to come which make present vehicle fleets heterogeneous with substantive number of BS IV vehicle. Beside improvement of engine technologies, existing BS IV vehicle fleet performance can be enhanced through improved fuel and lubricants solutions.

In recent years, deposit formation in the fuel systems for heavy-duty engines, using drop-in fuels, have become increasingly common. Drop-in fuels are particularly appealing because as they are compatible with existing engines, allowing for higher proportions of alternative fuels to be blended with conventional fuels. However, the precipitation of insoluble substances from drop-in fuels can result in fuel filter clogging and the formation of internal injector deposits, leading to higher fuel consumption and issues with engine drivability. The precise reasons behind the formation of these deposits in the fuel system remain unclear, with factors such as operating conditions, fuel quality, and fuel contamination all suggested as potential contributors. In order to reproduce and study the formation of internal injector deposits, for heavy-duty engines under controlled conditions, facilitating a more precise comparison to field trials, a novel injector test rig has been developed.

With the advent of electric and hybrid drivetrain in the commercial vehicle industry, electrically driven reciprocating compressors have gained widespread prominence. This compressor provides compressed air for key vehicle systems such as brakes, suspension systems and other auxiliary applications. To be a market leader, such an E-compressor needs to meet a myriad of design requirements. This includes meeting the performance by supplying air at required pressure and flow rate, durability requirements, oil free operation and having a compact design while maintaining cost competitiveness. The reed valve in such a compressor is a vital component, whose design is critical to meet the aforementioned requirements. The reed valves design has several key parameters such as the stiffness, natural frequency, equivalent mass, and lift distance which must be optimized. This reed valve also needs to open and close rapidly in response to the compressor operating speed.

This paper studies design parameters, selection of materials and structural analysis for an All-Terrain Vehicle (ATV) BAJA roll cage at the event site in any possible situation. SolidWorks 2022 was used for creating the prototype of the roll cage and then both static structural as well as dynamic crash analysis for the roll cage was done using Altair HyperWorks 2023 for various collisions like front, rear, side, rollover, torsional, front bump, rear bump, front roll over, side roll over and rear roll over. In addition to their corresponding deformation, Von Mises stresses were observed and a safety factor was calculated for these load cases which was found to be in the range of 1.5 to 3. Without reducing the roll cage’s strength, the roll cage designed for a four-wheel drive configuration is developed with driver comfort and safety in mind. Finding the optimal safety factor is the core objective of the analysis, as it ensures in any situation, the ATV’s roll cage will stay secure.

Most of the heavy commercial vehicles are installed with Pneumatic brake system where the medium is a pressurized pneumatic air generated with the reciprocating air compressor. Heating is an undesirable effect of the compression process during loading cycles as reciprocating air compressors are concerned. There fore it is necessary to reduce the delivery air temperature of compressor for safer operation of down stream products. The present investigation deals with the measurement of the delivery air tempearture of a typical 318 cc water cooled compressor. A through steady state conjugate heat transfer analysis is conducted for different speed and different cooling water flow rate to compare the delivery air temperature. Pressure drop across the cooling water flow path has been measured and optimum flow rate is arrived to meet the design requirement.

Abstract: Leak Before Break (LBB) is now widely applied in the pressure vessels and other pressurized components to failure by unstable crack initiation and propagation. This concept is also applicated in pneumatic brake system components to validate the structural rigidity of the devices. Pneumatic brake system component plays a vital role in the commercial vehicle platform. It consists of four major systems such as charging systems, actuating systems, control systems and actuators. Charging System includes compressor, reservoir, air dryer, and system protection valves. Compressor acts as an energy source for pneumatic air brake systems, reservoir is used to store the compressed air generated by the compressor, and system protection valves are used to divide and distribute the air flow to the brake system. Air dryer is used to absorb the moisture, oil particles and tiny foreign contaminant, regulate the system pressure, and blow off the excess pressure from the system.

Lift axle system is widely used in trucks and trailer to enhance the load carrying capacity by lowering the axle. Nowadays, this raising or lowering the axle is automated using electronic pressure switch. The Electronic pressure switch is used to sense the pneumatic pressure from Load Detection valve in Lift Axle control system and activates the solenoid valve which aids in filling the air in the lift bellows. The configuration used in this switch is Single Pole Double Throw (SPDT) which has 3 terminals such as 1 common contact,1 Normally open (NO) & 1 Normally closed (NC). The contacts of the switch change its state at forward switching pressure and returns to its normal state at the reverse switching pressure. Rubber diaphragm is one of the critical elements in this pressure switch which is used to avoid any leakage during the pressure transfer from the load detection valve. This rubber diaphragm is placed between the outer body of the switch and sensor holder.

One of the major goals of the automotive industry is to improve vehicular fuel efficiency and performance with much lesser percentages of harmful tailpipe emissions. One of the major technologies includes fuel cell electric vehicles (FCEV). Fuel cell electric vehicle can positively affect the transportation industry with regards to increase in the greenhouse gas emission, air pollution. A proton exchange membrane (PEM) fuel cell that is widely used in commercial vehicles takes hydrogen and oxygen to generate the electricity. Hydrogen stored either in liquid or compressed gas, is supplied from anode end and oxygen from atmosphere is supplied from cathode end. The atmospheric air, which enters fuel cell, also contains pollutants such as nitrogen oxides (NOx), Sulphur oxides (SOx), carbon monoxides and dioxides (CO, CO2), methane, ammonia etc.

Electric Vehicles and Battery-Fuel_Cell hybrid vehicles are increasingly becoming popular in the market, especially in the commercial vehicle segment. Range estimation and control is of paramount importance as it is the main cause of anxiety among the vehicle owners. This paper discusses application of Reinforcement Learning (RL) to achieve range control. In RL, the learning agent choses actions dependent on the state of the environment and gets a reward in return. Ultimately the agent will learn the policy of choosing the actions for each state such that his long-term reward is maximized. The technique of RL has been applied for various scenarios where in a look up table (between the states of a system and actions to be taken) needs to be developed for optimal performance.

A well-designed cooling system is crucial in construction machines for efficient heat dissipation from vital components, including the Radiator(RAD), Oil Cooler (OC) and Intercooler (IC). The radiator ensures optimal engine performance and longevity by maintaining a stable operating temperature. Oil Coolers preserve hydraulic system efficiency. Inter Coolers optimize engine performance through denser intake air. The robust cooling system enhances system reliability, reduces downtime, avoid overdesigned system, and increases operator safety in demanding construction environments. The size and location of heat exchangers are critical in cooling system design. Using 1D simulation tool KULI for cooling system design offers the benefits of comprehensive system simulation, optimization of thermal management, reduced development time and costs, enhanced system reliability, improved integration with other systems, and real-world testing and validation.

Climate across India varies from extreme Cold to extreme hot. As an objective to improve comfort to drivers during summer, it is mandate by Indian Government to introduce Air Conditioning in Trucks from June 2025. Air Conditioning system includes Evaporator, compressor, Condenser and expansion units. Condenser needs continuous air flow to reject the absorbed heat from driver cabin to surrounding air. This is possible by directing air through condenser by an external fan. For this condenser is remotely mounted with an electric driven fan or directly to the radiator-fan system. In this paper a case study is presented where Cooling system of a Non AC Intermediate Commercial Truck is modified for Air Conditioning application. Condenser is mounted on the radiator and the additional heat load is managed by a minor change in the system. Fan is operated based on coolant temperature and with additional controls for Air Conditioning. Simulations are done in a Thermal management software “KULI”.