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The motivation of this work is to respond to high cabin temperatures within a parked/stationary vehicle which may cause discomfort and lead to vehicular heatstroke. The system also intends to ensure sufficient limits of oxygen within the vehicle cabin to prevent asphyxiation to the cabin occupants. The rise in global temperature is affecting the quality of air and comfort of occupants inside a parked car. There have been several cases reported of pets and children being left unattended or unsupervised in a parked car for a long period of time which have led to their deaths due to asphyxiation. The use of cost-effective materials like high density plastics for interior cabin trim have also been proven to contribute to cancer because of the emission of benzene a carcinogen by these plastics when exposed to extreme temperatures for long periods of time.

The present work discusses the developed simulation model aimed to predict the heat rejection (HR) performance and external pressure drop characteristics of automotive charge air cooler (CAC). Heat rejection and airside pressure drop characteristics of CAC were predicted for the conditions of different charge air mass flow rates and different cooling air velocities. The lack of detailed research on CAC performance prediction has motivated the development of the proposed simulation model. The present 1-D simulation has been developed based on the signal library of AMESIM application tool. Input parameters for this simulation such as core size, tube pitch, tube height, number of tubes, fin density, louver angle, louver pitch, charge air mass flow rate, cooling air velocity, charge air inlet temperature, and ambient temperature. Heat rejection curve and airside pressure drop of CAC were the output of the present simulation.

Radiators are types of heat exchangers, which are used to transfer the heat from one fluid to another fluid. It is mainly used in automobile engine cooling systems and the radiators are the major source of heat rejection from the system by cooling the working fluid (generally water or glycol mixture). The application of radiators in the two-wheeler vehicle segment plays a vital role in increasing engine efficiency by maintaining the optimum temperature inside the engine assembly. As the technology advances with higher power requirements for the two-wheeler vehicle segment, thermal management of combustion engine becomes a critical part of it, resulting in the advancement of radiator technology in terms of compactness and thermal performance. In order to cater to the increasing demand for high-powered engines, performance optimization of two-wheeler radiators becomes an important aspect of design.

This paper discusses the methodology setup for grill opening area prediction at the early development phase of the product development lifecycle, using a commercially available 1D simulation tool- AMESIM. Representative under hood has been modeled using Grill, Condenser, Radiator, intercooler, fan, and engine components. Vehicle velocity is used as an input to derive the airflow passing through the grill and other under-hood components based on ram air coefficient, pressure drop through different components (Grill, Heat exchanger, Fan & Engine). This airflow is used to predict the top tank temperature of the radiator. Derived airflow is correlated with airflow obtained from CFD simulation. A balance has been achieved between cooling drag & fan power consumption at different grill opening areas for target top tank temperature. Top tank temperature has been predicted at two different extreme engine heat rejection operating points.

Currently the Automotive industry demands highly competitive product to survive in the global tough competition. The engine cooling system plays a vital role in meeting the stringent emission norms and improving the vehicle fuel economy apart from maintaining the operating temperature of engine. The airflow through vehicle subsystems like the grille, bumper, the heat exchangers, the fan and shroud and engine bay are called as front-end flow. Front end flow is crucial factor in engine cooling system as well as in determining the aerodynamic drag of vehicle. The airflow through the engine compartment is determined by the front-end vehicle geometry, the CRFM and CAC package, the engine back restriction and the engine compartment geometry including the inlet and outlet sections. This paper discusses the 1D modelling method for front-end airflow rate prediction and thermal performance by 1D method. The underbody components are stacked using heat stack and simulated in pressure mode.

As computer-aided engineering software tools advance, more simulation-based processes are utilized to reduce development time and cost. Traditionally, during the development of a new control algorithm dyno or on-road testing is necessary to validate a new function, however, physical testing is both costly and time consuming. This study introduces a co-simulation platform and discusses its use as an improved method of powertrain control logic development. The simulation platform consists of a dynamic vehicle model, virtual road network and simulated traffic objects. Engineers can utilize Matlab/Simulink along with other programs such as PTV Vissim, Tass Prescan, and AVL Cruise to create an integrated platform capable of testing and validating new control strategies. The structure and configuration of this virtual platform is explained in this paper, and an example use case is demonstrated. A driver model was developed to simulate realistic vehicle inputs.

E-fuels are proven to be a major contributing factor to reduce CO2 emissions in internal combustion engines. In gasoline engines, C1 oxygenate are seen as critical to reach CO2 and emission reduction goals. Their properties affect the fuel injection characteristics and thus the fuel mixture formation and combustion emissions. To exploit the full potential of e-fuels, the detailed knowledge of their spray characteristic is necessary. The correlation between the fuel content of C1 oxygenates and particulate emissions do not appear to be linear. To understand this correlation, the spray characteristics have to be investigated in detail. The reduced stoichiometric air requirement leads to an increase of the injected fuel mass, which has to evaporate. This can lead to a changed fuel film interaction within the combustion chamber walls and therefore a change of particle formation.

To solve the engine performance deterioration and emission problems caused by fuel spray impingement on combustion chamber wall from direct injection internal engines, we bring out the new fuel injection concept, which we call it the impinging injection method. The impinging injection method uses two opposite injectors and tries to achieve spray atomization effect from the fuel sprays collision. A constant volume combustion chamber was used to confirm the spray characteristics and the combustion improvements. Previous study confirmed a significant reduction of spray/wall impingement and combustion improvements. Therefore, in this study, from the aspect of surrogate fuel, we investigated the spray and combustion characteristics of n-butanol addition blend with iso-octane and n-hexadecane, respectively, by using impinging injection and multi-impinging injection with different injection timing conditions. The n-butanol addition ratio ranged from 0% to 50%.

The boiling point curve of fatty acid methyl esters (FAME), or biodiesel fuel, can be adapted to that of diesel fuel by breaking FAME down into a low-molecular structure using a cross-metathesis reaction with a short-chain olefin. Reformulated FAME by a metathesis reaction consists mainly of medium-chain olefins and fatty acid methyl esters. In the present study, the engine performance and exhaust emissions from reformulated FAME were investigated through engine bench tests. Surrogate fuels made from typical chemical components of reformulated FAME were used to clarify the effects of respective components upon combustion. Surrogate fuels were made by mixing 1-decene, 1-tetradecene, methyl laurate, methyl palmitate, and methyl oleate to simulate the boiling point, oxygen mass concentration, and calorific value of reformed biodiesel of waste cooking oil methyl ester (WME). A single-cylinder diesel engine equipped with common-rail-type injection system was used.

Autoignition delay times of two full blend gasoline fuels (high and low RON) were explored in a rapid compression machine. CO2 dilution by mass was introduced at 0%, 15%, and 30% levels with the O2:N2 mole ratio fixed at 1:3.76. This dilution strategy is used to represent exhaust gas recirculation (EGR) substitution in spark ignition (SI) engines by using CO2 as a surrogate for major EGR constituents(N2, CO2, H2O). Experiments were conducted over the temperature range of 650K-900K and at 10 bar and 20 bar compressed pressure conditions for equivalence ratios of (Φ =) 0.6-1.3. The full blend fuels were admitted directly into the combustion chamber for mixture preparation using the direct test chamber (DTC) approach. CO2 addition retarded the autoignition times for the fuels studied here. The retarding effect of the CO2 dilution was more pronounced in the NTC region when compared to the lower and higher temperature range.

The presence of unsaturated methyl esters in biodiesel makes it susceptible to oxidation and fuel quality degradation upon long-term storage. In the present work, the effects of oxidation of Karanja biodiesel upon long-term storage on the combustion and emission characteristics of a heavy-duty truck diesel engine are studied. The Karanja biodiesel is stored for one year in a 200 litres steel barrel at room conditions to mimic commercial storage conditions. The results obtained show that compared to diesel, the start of injection of fresh and aged biodiesels are advanced by ~2-degree crank angle, and the ignition delay time is reduced. Aged biodiesel showed a slightly smaller ignition delay compares to fresh biodiesel. The fuel injection and combustion characteristics of fresh and aged biodiesels were similar at all the load conditions. Both fresh and aged biodiesels produced higher oxides of nitrogen (NOx) and lower smoke emissions compared to diesel.

The piston assembly is the major source of tribological inefficiencies among the engine components and is responsible for about 50% of the total engine friction losses, making such a system the main target element for developing low-friction technologies. Being a reciprocating system, the piston assembly can operate in boundary, mixed and hydrodynamic lubrication regimes. Computer simulations were used to investigate the synergistic effect between low viscosity oils and cylinder bore finishes on friction reduction of passenger car internal combustion engines. First, the Reynolds equation and the Greenwood & Tripp model were used to investigating the hydrodynamic and asperity contact pressures in the top piston ring. The classical Reynolds works well for barrel-shaped profiles and relatively thick oil film thickness but has limitations for predicting the lubrication behavior of flat parallel surfaces, such as those of Oil Control Ring (OCR) outer lands.

In the present work, a system approach to the tribological optimization of passenger car engines is demonstrated. Experimental data and simulation results are presented to demonstrate the role of surface specifications, ring pack, and lubricant on the piston/bore tribology. The importance of in-design “pairing” of low-viscosity motor oils with the ring pack and the cylinder bore characteristics in order to achieve maximum reduction in GHG emissions and improvement in fuel economy without sacrificing the endurance is elucidated. Earlier motored friction data for two different gasoline engines - Ford Duratec and Mercedes Benz M133 - using motor oils of different viscosity grades are now rationalized using AVL EXCITE® piston/bore tribology simulations. The main difference between the engines was the cylinder bore surface: honed cast iron vs thermally sprayed, and the valve train type: direct-acting mechanical bucket (DAMB) vs roller finger follower (RFF).

The research on reducing emissions from automotive engines through modifications in the combustion mode and the fuel type is gaining momentum because of the increasing contribution to global warming by the transportation sector. The combustion and emission formation in the advanced low temperature combustion (LTC) engine strategies are susceptible to fuel molecular composition and properties. Ignition timing in LTC strategies is primarily controlled by fuel composition and associated chemical kinetics. Thus, tailoring of fuel properties is required to address the limitations of LTC in terms of lack of control on ignition timing and narrow engine operating load range. Utilizing fuel blends and additives such as nanoparticles is a promising approach to achieving targeted fuel property. An improved understanding of fundamental processes, including fuel evaporation, is required due to its role in fuel-air mixing and emission formation in LTC.

Collaborative research outlined in this paper documents recent engine and emission performance of a newer, more robust small SI engine across a sweeping range of relative humidity (RH) having fixed intake air temperature and pressure. The experimental results will show that power correction references to SAE J1349 as well as humidity correction (Kh) reference in EPA 40 CFR §1065 may generically be applied, but do not accurately compensate for the extent of correction required. The test results shared from this particular performance testing of a Kohler KT745 carbureted engine develops the case for a more diverse and less conservative approach to a one-size-fits all strategy related to humidity corrections within the small SI testing community. Moreover, humidity effects for both observed and corrected power, as well as emission corrected constituents (not just NOx) are generally greater than would otherwise be assumed from the literature.

In this work, a dynamically loaded hydrodynamic journal bearing test rig is developed and introduced. The rig is a novel design, using a hydraulic actuator with fast acting spool valves to apply load to a connecting rod. This force is transmitted through the connecting rod to the large end bearing which is mounted on a spinning shaft. The hydraulic actuator allows for fully variable control and can be used to apply either static load in compression or tension, or dynamic loading to simulate engine operation. A variable speed electric motor controls shaft speed and is synchronized to the hydraulic actuator to accurately simulate loading to represent all four engine strokes. A high precision torque meter enables direct measurements of friction torque, while shaft position is measured via a high precision encoder.

The materials commonly employed in the automotive industry are various and depend on the specific application field. For what concern the internal combustion engines the choice is guided by the thermomechanical performance required, technological constraints and production costs. Actually, for high-performance engines, steel and aluminium are the most common materials selected for the piston and the cylinder liner manufacturing. This study analyses the effect of possible material choice on the interaction between piston and cylinder liner, via Finite Element analyses. A motorcycle engine is investigated considering two possible pistons: one (standard) made of aluminium and one made of steel. Similarly, two possible cylinder liners are considered, the original one made of aluminium and a different version made of steel obtained by simply thinning the aluminium component in order to obtain two structurally equivalent components.

Thermal fatigue crack failure is becoming the most important aspect in modern cylinder head design as modern engines are striving towards higher peak cylinder pressures. Thermal cracks are developed in the cylinder head due to thermal gradients generated because of operating conditions. Paper scope comprises analytical and experimental study on reduction of combustion deck temperature and enhancing combustion deck fatigue margin of a diesel engine through introduction of scallop on the combustion face. There are methods such as cooling jacket optimization, faceplate insertion, scallops and other measures to reduce the temperatures on the combustion deck.

The present paper describes a CAE analysis approach to evaluate the transient cylinder head gasket sealing performance of a turbo charged GDI engine in the bench test development. In this approach, both transient gasket sealing force and gasket wear work are calculated to allow design engineers to find out the root cause of cylinder head gasket leakage failures. In this paper, the details of the method development are described. Firstly how to use and get the cylinder head gasket property are described, which is the basic theory and data for the gasket sealing analysis. A transient heat transfer calculation for accurately simulating the engine thermal shock test is established, which is mapped to the transient gasket sealing calculation as pivotal boundary.

The article proves the necessity for heating the air in the pneumatic engine of a hybrid power unit designed for moving a compact wheeled vehicle. The aim is to improve the pneumatic engine operation indicators by heating the compressed air before it is supplied to the cylinder using the obtained theoretical and experimental studies. For the easy-to-use of assessing the effectiveness of heating the air supplied to a pneumatic engine, the experiments were carried out by two pressure ps = 0.7 MPa and ps = 0.9 MPa, according to them the testing of a pneumatic unit was conducted without heating the compressed air at the temperature equal to the ambient temperature Ts = 293 K. Also, during the experiments a pneumatic engine was tested at other temperatures while supplying the compressed air at the inlet to the engine cylinder.