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To reduce exhaust emissions in commercial vehicles, hydrogen, as a carbon-free fuel, is a reasonable alternative to conventional fuels. In order to circumvent the current problem of hydrogen availability, the use of a gas engine for heavy duty vehicles (HDV), which is able to operate with pure compressed natural gas (CNG), pure hydrogen as well as any mixture of these both gases, is sensible. For this purpose, an operating concept for a gas engine was developed, which is able to operate with an arbitrary hydrogen-natural gas mixture ratio. Therefore, the mixture formation of a hydrogen-natural gas-air mixture was analyzed in a 3D CFD simulation. The results for pure hydrogen and pure CNG operation show a very good homogenization of the fuel distribution at the point of ignition when an outward-opening injector was used.

Automobile industry is facing challenges in the field of technological innovation and achieving minimum Total Cost of Ownership (TCO) despite rise in fuel prices. To overcome these challenges is certainly a challenging task. In doing so, automobile sector is mainly focused on passenger safety, comfort, reliability, meeting stringent emission norms, and above all reducing the vehicle fuel consumption. Referring to the Paris climate agreement, and India’s commitment to reduce the CO2 intensity by 33% - 35% by 2030 below the 2005 levels [1], it is imperative to lay down strong policies and procedure to curb the fuel consumption to contribute for reduction in carbon foot print and oil imports. Transportation sector is majorly responsible for the GHG Emission of which the CO2 emission from commercial vehicles is nearly 73% [2], although the total sales of commercial vehicles are around 4% of cumulative vehicle sales.

Increasing demands for high fuel efficiency requires imperative light weighting of automotive structure, but this adversely affects the NVH performance since transfer path of noise sources like engine, road, wind to vehicle interior through the panels weakens. Also increasing customer centric approach drives the urge to provide world-class comfort which is cost-effective too. Sound Packaging helps us to optimize this transfer paths through the panel, and can effectively complement efforts of testing team, by reducing the redundant iterations required to conclude to most effective trims to be put on. statistical energy analysis based simulations is employed for carrying out these iterations at the virtual validation gateway itself.

In the current customer centric automotive market, NVH is one of the prime focus for the automotive industry. Almost all light commercial vehicles in the market are with hydraulic power steering system. Hydraulic power steering pump is heart of the steering system which circulates the hydraulic oil to steering gear for assisting the driver. One of the NVH problem which is inevitable with the hydraulic vane pump is humming noise and this is perceived as an irritant by end user. This paper describes a novel technique for reducing the humming noise which is perceived at driver ear level. Base vehicle level objective measurements is carried out to set the acceptance criteria. Existing design is optimized as per CAE iterations and vehicle updated with the multiple solutions and objective measurements are recorded. Driver ear level noise reduction upto 4 dB(A) perceived which meets acceptance criteria.

With the improvement of standard of living, air conditioning has widely been applied in buses. However, in air conditioning buses air distribution is still needs to be improved, One of the main reasons for this sub-quality comfort is two air flow louvers arrangement for 3x2 layout air conditioner buses. Air conditioning buses hatrack louvers are an integral part in providing comfort to passengers. General trend of the numbers of louvers provided to passengers is two louvers for three seats. Disadvantage of having conventional two louvers is that, there is always one passenger left with no option of directing air towards that person. This lead to an opportunity to design three louvers type hatrack instated of conventional two louvers hatrack, for 3x2 seating layout of buses. This way all three passengers can control the louvers for their own comfort and mass of air flow is sufficient for third passenger as well.

Steering system is responsible for providing a precise directional control to the vehicle. The Hydraulic Power Assisted Steering (HPAS) system is commonly used in passenger cars and commercial vehicles due to low cost. Power steering pump develops and delivers required pressure to provide assistance while steering. It reduces the effort required to steer the vehicle. Steering pump (generally vane type) is a critical part providing hydraulic pressure assistance to rack and pinion or gear box. Basically the hydraulic pump noise can be classified as ‘Moan Noise’ and ‘Whine Noise’. The noise generated by power steering pump pressure pulsation is termed as ‘Moan’ and ‘Whine’ based on operational induce frequency. As power train becomes quieter, it becomes more perceivable at typical engine operating speed range and gives impression of poor refinement and quality.

There is a higher demand for quieter tractors in the agri-industry, as the continued exposure to noise levels have disastrous effects on operator’s health. To meet the world-wide regulatory norms and to be the global market leader, its mandatory to develop the comfortable tractor which meets homologation requirements and customer expectations. Typically, Operator Ear Level (OEL) noise has been evaluated in the test, after First Proto has been made. This approach increases cost associated with product development due to late changes of modifications and testing trails causing delay in time-to-market aspect. Hence, there is a need to develop the methodology for Predicting tractor OEL noise in virtual environment and propose changes at early stage of product development. At first, full vehicle comprising of skid, sheet metals and Intake-exhaust systems modelled has been built using Finite Element (FE) Preprocessor.

The air purifier industry has seen a growth in terms of demand and sales lately. All credit goes to massive Industrialization in developing countries such as India. The most harmful of the pollutants are PM 2.5 articulates and NOx Emissions. This leads to the new trend of customers become health and comfort conscious and willing to pay more for better and improved transportation. To satisfy these demands, COEM’s are developing more numbers of Air conditioning buses. Although the OEM’s are meeting this demand of quantity, the quality of air from air conditioner is still suffer. One of the main reasons for this poor air quality is because of the ineffectiveness of conventional air conditioner air filters to control particulate materials i.e. PM2.5, biological pollutants i.e. microbes, bacteria, viruses, and gaseous pollutants i.e. CO, CO2, SO2, NOX, O3 & VOCs in air. As per various researches, health problems associated with bus occupant compartment air quality appear more frequently.

Highway transportation using truck is an important transport mode of goods and product to their destination. Commercial vehicle is expensive mode of transportation so it will be protected from failure. For Heavy duty truck they are fully loaded at one side of transportation and other side empty transportation. In such case lift axle grounded when truck is loaded and when truck is empty it is in lift condition. Lift axle is play important role while loading so it is important that it should not fail. Many times lift axle fails at weld location due several load come on the axle. In this paper study of weld failure to vertical, braking and lateral load come on lift axle when truck is in loading condition. Weld failure check in CAE analysis with various load cases and compare with actual physical vehicle failure. Weld failure correlation well correlate when actual loading are consider in analysis. For analysis loading data is measure from RLDA data that will be used for analysis.

The field performance of a machine is conventionally analyzed using tools of virtual validation such as physics-based simulation models. Machine performance test data is typically not incorporated for performance evaluation using these tools. The present work aims to demonstrate the use of Data Analytics (DA) as a tool to analyze this data for predictive purposes. It aims at establishing numerical relationships of engineering interest within the data, which would otherwise be complex if done only using physics-based models. Engine operation data spanning over three months, comprising of multiple channels, of an off-highway machine, is used for model development. Machine fuel burn rate is chosen as the dependent variable. Several independent variables such as engine speed, charge air pressure, NOx production level, are chosen based on their correlation with the dependent variable and upon engineering interest.

In a modern world, the tractor customer demands are increasing for more comfortable, new technology, fuel efficient and quieter vehicle. The customer’s expectation for NVH refinement often challenges the limitations for tractor designs. For smaller tractors Hydrostatic Transmission (HST) is need due to higher demand for fuel efficiency, lightweight powertrain, and the operation will become easy in the farm field. With the Hydrostatic Transmission (HST) tractor without damper, there is a technical challenge like withstanding of the sudden impacts from the implements which are connected to PTO during field operations. The NVH behavior in driveline is critical phenomena which can cause the discomfort to end users and structural failure of driveline parts. During gear engagement due to sudden variation in torque the driveline parts are tends to clash each other because of lashes which will create high level of angular acceleration and noise.

This paper focuses on partial encapsulation technique for reducing air-borne noise from the rocker cover of a commercial vehicle diesel engine. Due to increasing awareness, customers demand for improvised NVH (Noise Vibration and Harshness) performance in modern day vehicles. Better NVH performance implies better comfort for passengers as well as vehicle operator. This further increases the driver up time due to reduced driver fatigue. In order to improve NVH performance of existing vehicle and observe different noise and vibration zones, detailed noise and vibration mapping was carried out on one of our vehicle platform. It is observed that engine noise is one of the major contributors for interior noise, apart from road inputs etc.

Small commercial vehicles (SCVs) are the drivers of a major part of India’s indirect economy, providing the most efficient means of transport. With the introduction of BS-VI norms, some major overhauls have been done to the SCV models to meet BS VI norms in challenging timeline for early market entry. This forced to automotive designers towards challenge of cost competitiveness as well as refinement level to survive in this competitive market. This paper explains the systematic approach used to overcome challenges of higher tactile vibrations, higher in-cab noise because of BS VI requirement in 2 cycle engine required for small commercial vehicle. The solutions were need to be worked out without compromising the other performance attributes like total cost of ownership, fuel economy, ease of servicing and cost effectiveness.

In today’s automobile industry refined NVH performance is a key feature and of high importance governing occupant comfort and overall quality impression of vehicle. In this paper interior noise and vibration measurement is done on one of the light truck and few dominant low frequency noise booms were observed in operation range. Modal analysis was done for the cabin at virtual as well as experimental level and few modes were found close to these noise booms. Vibrations were measured across the cabin mounts and it was found that the isolation of front mounts is not effective at lower frequencies. Taking this as an input, the mount design was modified to shift the natural frequency and hence improve the isolation behavior at the lowest dominant frequency. This was followed by static and dynamic measurement of the mounts at test rig level to characterize the dynamic performance and stiffness conclusion.

Adjuster rings are used in commercial vehicle axle assembly to preload differential bearings and provide support in the axial direction. Adjuster along with the carrier and bearing cap combined to form a threaded joint. Adjuster with external threads engages with internal threads formed in carrier and bearing cap. Preload in differential assembly maintains the system rigidity and helps to maintain an optimized hypoid gear engagement. An adequate preload is important to achieve a desirable bearing life. Reduction in thread engagement at adjuster joint fully or partially will cause a reduction in preload and can lead to gear misalignment. This can cause severe durability concerns. In some cases, it is observed that under vehicle operating loads adjuster ring is backed off from its assembled condition by bending the split pin (split pin is, positive lock, used to maintain adjuster position) and adjuster threads were stripped off.

Downsizing and Light weighting is the latest trend in the automotive industry to achieve more fuel efficient, compact and cost effective design of vehicles. Powertrain components compromise of more than 45% of the total vehicle weight. Automakers are putting significant efforts to reduce the weight of power train components. Integrated design of aluminum Engine Head and Intake manifold has been successfully implemented. Now currently we have identified the gear box housings for downsizing in light duty trucks i.e. Existing light duty trucks Cast Iron transmission. This design has been successfully modified with integrated clutch housing and transmission housing, using lightweight aluminum as the new material, using simulation tools. This lead to weight savings of up to 30% and cost savings of 20-25% as compared to existing cast iron designs. Using an integrated design reduces the assembly cost, makes the design more compact and gives better weight balance.

Fuel efficiency is critical aspect for commercial vehicles as fuel is major part of operational costs. To complicate scenario further, fuel efficiency testing, unlike in passenger cars is more time consuming and laborious. Thus, to save on development cost and save time in actual testing, simulations plays crucial role. Typically, actual vehicle speed and gear usage is captured using reference vehicle in desired route and used it for simulation of target vehicle. Limitation to this approach is captured duty cycle is specific to powertrain and driver behavior of reference vehicle. Any change in powertrain or vehicle resistance or driver of target vehicle will alter duty cycle and hence duty cycle of reference vehicle is no more valid for simulation assessment. This paper demonstrates approach which uses combination of tools to address this challenge. Simulation approach proposed here have three parts.

Heavy commercial vehicle axle shafts are designed for torsion load. Typically, axle shaft fracture mode during the test is torsional in nature through either shaft body diameter or spline end. However, some of the field return axles shows fracture mode on axle shaft flange. This fracture mode does not resemble with a typical lab test torsional fracture. Metallurgical investigation report indicated that the fracture mode is bending in nature. This paper thus focuses on detail study of change in boundary condition and load transfer path under abusive vertical bending load on axle. A detail finite element analysis is performed to understand stress state change in axle shaft under this condition. A fracture hypothesis is proposed based on observations of finite element analysis results. A detail case study is presented depicting correlation of proposed hypothesis with physical fracture mode.

Braking system components generally are safety critical products. Commercial vehicles braking systems are of highly safety critical as they pose a serious threat to life and property. Therefore, a system must be designed and validated to minimize the effects of component failure of these portfolios of products. In order to avoid accidents due to brake failures, this paper mainly focuses on analysis of loss of pneumatic fluid pressure in the components of the braking systems. Leakage of pneumatic fluid pressure through the sealing in braking system is one of the major reasons for the failure of the brakes in the vehicles. The aim of the present study is to simulate the lab failure and improve the design using finite element analysis. Also, the optimized design is validated by experimentally. A finite element model is developed in Ansys Workbench to study the behavior of the sealing ring under assembly conditions.

In recent days, the usage of disc brake is increased acutely in commercial vehicle applications apart from the passenger vehicles. The main advantage of using disc brake is reducing the stopping distance, temperature and wear between the disc and pad. During the braking, kinetic energy of the vehicle is converted into thermal energy due to the friction between disc and pad. To maintain the temperature between the disc and pad is critical for the overall performance of the disc brake and safety of the vehicle. The process of vehicle braking is a dynamically thermal structure coupling problem which is complex in nature. In this study, temperature between the disc and pad is determined using Finite Element Analysis for two different pad configurations. As per recent vehicle norms by the government the axle load is increased by 20 % which requires increased braking force and will leads to high temperature in the disc pad interface.