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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.

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.

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.

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.

Overall cycle time and prototype testing are significantly decreased by assessment of cooling module performance in the design stage itself. Hence, Front End Cooling and Thermal Management are essential components of the vehicle design process. Performance of the cooling module depends upon a variety of factors like frontal opening, air flow, under-hood sub-systems, module positioning, front grill design, fan operation. Effects of design modifications on the engine cooling performance are quantified by utilizing computational fluid dynamics (CFD) tool FluentTM. Vehicle frontal configuration is captured in the FE model considering cabin, cargo and underbody components. Heat Exchanger module is modelled as a porous medium to simulate the fluid flow. Performance data for the Heat Exchanger module is generated using the 1D KuliTM software. In this paper, CFD simulation of Front End Cooling is performed for maximum torque and maximum power operating conditions.

The urea NOx selective catalytic reduction (SCR) is an effective technique for the reduction of NOx emitted from diesel engines. Urea spray quality has significant effect on NOx conversion efficiency. Air less injection is one of effective, less complex way of injecting urea spray into the Exhaust stream. Further with air less injection it become more challenging in an engine platform of ~3 to 4L where Exhaust mass flow and temperature are relatively less. The droplet diameter and velocity distribution of De-Nox system has taken as input along with Engine raw emission data for a numerical model. The atomization and evaporation of airless urea injection systems were modeled using computational fluid dynamics. The numerical model was validated by the experimental results.

Engine down speeding is rapidly picking up momentum in many segment of world market. Numerous engine down speeding packages from OEM have been tailored to take advantage of the increased efficiencies associated with engine down speeding. Running engine at lower rpm has numerous advantages. The most obvious of these is reduced fuel consumption, since the engine can spend more time running within its optimum efficiency range. By down speeding, the engine is made to run at low speeds and with high torques. For the same power, the engine is operated at higher specific load- Brake Mean Effective pressure (BMEP) which results in higher efficiency and reduced fuel consumption-Brake Specific Fuel Consumption (BSFC). The reasons for increased fuel efficiency are reduced engine friction due to low piston speeds, reduced relative heat transfer and increased thermodynamic efficiency.

Paper explains conversion of existing drum brake system to disc brake system with complete digital validation at structural as well as thermal level to make sure First Time Right Design before physical part development. To provide leverage to quick design, modification and selection of brake system according to vehicle configuration, a virtual computational fluid dynamics (CFD) simulation process is developed and validated with test results. Temperature variation over brake drum and disc in internal standard braking cycle is measured virtually and correlated with test results. Also Fade testing criteria’s were considered during CFD analysis. This up gradation is must considering technology enhancement trend and safety in automotive segment. In current competitive market scenario and as per customer requirements, front disc brake module is becoming necessary not only for passenger segment but also for commercial segment vehicle.

An engine cooling system is required to maintain stable operating temperature for the engine and prevent it from overheating. Thermal distortion of engine parts can take place if proper cooling is not maintained and engine may loss efficiency. One of the major problem in this domain is to incorporate separate cooling systems for the different variants of engines (different power rating). A single optimized cooling unit is desired to manage the entire range of engine rated power. The factors that affect the cooling system are front end grill opening area, air recirculation, location of snorkel inlet, radiator core size, which need to be tuned to get appropriate results. The above parameters are tuned to obtain appropriate results using the Computational Fluid Dynamics (CFD) simulations. In the next stage, on road cooling trials are performed and real time data is collected.

India being a developing nation, there is significant improvement of road infrastructure across the country as well as the spending power and earnings of the common man. This leads to the new trend of customers willing to pay for a more comfortable travel through AC buses. To satisfy these demands, OEM’s are forced develop and manufacture huge numbers of AC buses. Although the OEM’s are meeting this demand of quantity, the quality aspect of the buses, i.e., climate comfort, is still subpar. One of the main reasons for this sub-quality comfort is the non homogenous distribution of air flow along the bus. This non homogeneity leads to the centre of the bus having very high air flow and thus overcooling conditions, while the front and rear of the bus receive very little air flow and thus receive under-cooling conditions. To solve this concern of non homogeneity, we incorporated a new design in the hatrack, through the implementation of baffles and deflector in the hatrack.

For the upcoming norms of BSVI, it is very important to keep the balance of emission and fuel economy. In these paper different concepts for exhaust gas temperature management will be analyzed and compared. In transient and steady conditions with medium and low load, the effects of active control strategies on exhaust thermal management were studied at the test bench, which include E waste gate intake throttle valve opening, injection advance angle, injection pressure and post injection. The comparison study was factors impacting the fuel economy and temperature management along with to meet WHSC & WHTC emission. The DOE was done to understand the best suitable match with the above function to achieve the optimized fuel economy and BSVI legislative requirement. Different test where carried with 0-100% of opening of intake throttle valve, E waste full open and late post injection to understand the thermal management of engine in part and full load.

Passenger vehicles are used as one of the frequently used and versatile mode of transport. Commercial buses cater to short to long distance travel for city as well as highway applications. Thus, passenger ride comfort becomes paramount for the salability of the vehicle. Generally, it is observed that the rear seat experiences the worst ride comfort characteristics due to rear overhang and pitching characteristics of buses. Therefore the objective of this project is to improve the rear seat vibrations of passenger bus by tuning damper characteristics. Shock absorbers, being a low cost and easily interchangeable component is tuned first before optimizing other suspension parameters. The methodology is as follows: first, a 4 degree of freedom mathematical model is created on MATLAB Simulink R2015a environment. Time domain data is obtained by road load data analysis and used as an input for the mathematical model.

In an electric vehicle, engine is replaced with battery and transmission is replaced with traction motor. Thermal management of electric battery and motor became a necessary evaluation step in the design and development process of electric vehicles. The temperature of the traction motor coolant is required to be maintained below 600C to ensure proper functioning of the system. Coolant takes away heat from traction motor, motor controller along with an on-board charger in battery charging and discharging conditions. In this paper the cooling unit selection for the total required heat rejection from all three components is analytically calculated and thermal management methodology of liquid-cooled Electric Motor is being studied and documented with the help of numerical simulation. The results are further validated with test results in Electric bus for city application.

The discussed invention is centered on the evaporative cooling of a vehicle cabin, introducing a novel concept of humidity control. Unlike conventional Air Conditioning (AC) systems that operate on the Vapor Compression Refrigeration Cycle (VCRC), which tend to be costly and contribute to higher fuel consumption due to the engine-driven compressor in automobiles, there is currently no other Original Equipment Manufacturer (OEM) fitted cabin cooling option available to address this issue. This paper introduces the idea of a humidity-controlled evaporative cooler. The objective of humidity control is achieved through a controller unit that receives feedback from a humidity sensor, subsequently regulating the operation of the water pump. The ambient air is passed through a humidified honeycomb pad, cooling through the principle of evaporation. To prevent any leftover water droplets from entering the cabin, a polyester nonwoven filter has been integrated into the system.