Automotive Configuration Research Articles

NUMERICAL INVESTIGATION ON SMOKE MANAGEMENT IN UNDERGROUND BRANCHED TUNNELS

Soot is perhaps the most harmful element in vehicle tunnels fire as smoke moves harmonize with the way passengers flee. It decreases visibility and can cause suffocation fatalities.
 This paper presents an empirical analysis on the effect of removing smoke through different ventilation systems on smoke distribution inside the vehicle tunnel, such as water mist system with transverse ventilation with several extractions of exhaust fans Sustainable human conditions were also tested. FDS 2019 ver. was used to predict temperature, visibility, and concentration of co.
 Motivation/Background: Present work to investigate the effect of extracting the smoke by different system of ventilation on smoke spread inside the vehicular tunnel. 
 Method: By FDS 2019 that used governing equations and naver-stocks equations. 
 Results: We predicted in this paper smoke spread, temperature distribution, co concentration distribution and visibility. 
 Conclusions: This study looks at the importance of smoke control generally as well as the smoke control criteria in the automotive tunnel configuration which acknowledged them. 
 Because the smoke barrier water mist screen with a transverse ventilation device improves the smoke removal technique. FDS is a valuable method for simulating smoke diffusion as well as other effects.

Performance Analysis of a Common-rail Diesel Engine Fuelled with Different Blends of Waste Cooking oil and Gasoil

An experimental campaign was performed to study the behavior of a common-rail Diesel engine in automotive configuration when it is fuelled with blends of Diesel fuel (DF) and waste cooking oil (WCO). In particular the tested fuels are: B20 blend, composed of 20% WCO and 80% DF; B50, composed of 50% WCO and 50% DF; WCO 100% and 100% DF.In order to fuel the engine with fuel having a similar viscosity, this quantity, together with density, has been measured at temperature ranging from rom to about 80̊C. According to these measurements, before fuelling the engine B20 was heated up to 35̊C and B50 to 75̊C.An in-house software was developed to acquire the data elaborated by the electronic control unit.Results show the trend in torque and global efficiency at different gas pedal position (gpp) and different engine speed. The experiments show that larger discrepancies are measured at smaller gpp values, while at larger ones differences become smaller. A similar trend is noticed for engine global efficiency.

Modifications to Improve Fuel Consumption in the Remanufacture of Spark-Ignition Engines for Electric Generators

This paper describes the development of a water-cooled, lean burn, gaseous fueled engine designed for distributed power installations. Electric generators have become popular because they provide a portable supply of electrical power at consumer demand. They are used in critical need areas such as hospitals and airports, and have found their way into homes frequented with power outages or homes in remote locations. Gensets are available in a wide variety of sizes ranging from 1 kilowatt (kW) to thousands of kilowatts. In the midrange, the power sources are typically spark-ignition, automotive type internal combustion engines. Since engines designed for automotive use are subject to different emission regulations, and are optimized for operation at revolutions per minute (RPM) and brake mean effective pressures (BMEPs) above that of electric generator engines, modifications can be made to optimize them for gensets. This work describes modifications which can be made during remanufacturing an automotive engine to optimize it for use as a generator engine. While the work recognizes the potential for cost savings from the use of remanufactured automotive engines over that of using new automotive engines and the majority of the design constraints were adopted to reduce engine cost, the main focus of the work is quantifying the increase in fuel efficiency that can be achieved while meeting the required EPA emission requirements. This paper describes the seven combustion chamber designs that were developed and tested during this work. Friction reduction was obtained in both valve train and journal bearing design. The engine optimized for fuel efficiency produced a maximum brake thermal efficiency (BTE) of 37.5% with λ = 1.63. This yielded an EPA test cycle average brake specific fuel consumption (BSFC) of 325 g/kW hr. Modification of the spark advance and low load equivalence ratio to meet EPA Phase III emission standards resulted in an EPA test cycle average BSFC of 330 g/kW hr. When the engine used in this research was tested in its unmodified, automotive configuration under the EPA compliant test cycle, its EPA test cycle average BSFC was 443.4 g/kW hr. This is a 34% increase in fuel consumption compared to the modified engine.

Constraint-based and SAT-based diagnosis of automotive configuration problems

We compare the concepts and computation of optimized diagnoses in the context of Boolean constraint based knowledge systems of automotive configuration, namely the preferred minimal diagnosis and the minimum weighted diagnosis. In order to restore the consistency of an over-constrained system w.r.t. a strict total order of the user requirements, the preferred minimal diagnosis tries to keep the most preferred user requirements and can be computed, for example, by the FASTDIAG algorithm. In contrast, partial weighted MinUNSAT solvers aim to find a set of unsatisfied clauses with the minimum sum of weights, such that the diagnosis is of minimum weight. It turns out that both concepts have similarities, i.e., both deliver an optimal minimal correction subset. We show use cases from automotive configuration where optimized diagnoses are desired. We point out theoretical commonalities and prove the reducibility of both concepts to each other, i.e., both problems are FPNP-complete, which was an open question. In addition to exact algorithms we present greedy algorithms. We evaluate the performance of exact and greedy algorithms on problem instances based on real automotive configuration data from three different German car manufacturers, and we compare the time and quality tradeoff.

Pollutant Emissions in Common-rail Diesel Engines in Extraurban Cycle: Rapeseed Oils vs Diesel Fuel

The new energy strategy of EU (i.e., Directive 2009/28/EC) requires increasing the use of biofuels in transports up to at least 10% of the total fuel consumption. In the last years, the share of Diesel engines in automotive applications reached about 55% in EU market, thus trying to widen the alternatives to Diesel fuel is very important. In this framework straight vegetable oils (SVO) can represent one of the available possibilities at least in some specific applications (i.e., public transportation, hybrid or marine propulsion, etc.). SVO properties may be very different form Diesel fuel, thus operating a Diesel engine with SVO might result in some problems, especially in automotive configuration where the electronic unit acts as if it is working with Diesel fuel. This reflects in possible engine power and torque reduction, maintenance problems, and pollutant emissions during vehicles running. The latter aspect is the focus of the present paper. In this work, we used a turbocharged, four stroke, four cylinders, water cooled, common-rail multijet Diesel engine in automotive configuration to simulate the extraurban cycle according to the EU standard, comparing pollutant emissions in case of SVO and gasoil fuelling.

Vegetable Oils as Fuels in Diesel Engine. Engine Performance and Emissions

The EU new energy strategy represents a challenge and a boost for industries and researchers pushing them to find new solutions to supply the energy demand complying with new environmental requests. The transport sector is one of the most addicted to oil product and then pollutant. A new bio-fuels generation is being studied, but the use of the ones already available should be increased. The use of vegetable oils (VO) and waste cooking oils (WCO) could represent interesting alternative fuels for Diesel engines in some specific applications (i.e., public transportation, hybrid or marine propulsion, etc.). Moreover, VO can be produced almost everywhere in the world in relatively small plants, and WCO would represent the use of a waste material which otherwise should be disposed. However, operating a Diesel engine (DE) with a different fuel might results in some problems. Indeed VO and WCO have different characteristics compared to Diesel fuel (i.e, a smaller heating value, a larger density and viscosity), and this can affect the operation of a DE. In particular the DE is expected to have some problem at the injection system and power loss.In this work different vegetable oils (both straight and waste) are used to fuel a DE in automotive configuration and study its behavior. Tests are performed using a turbocharged, four stroke, four cylinders, water cooled, common-rail multijet DE. The influence of fuel used on engine power, specific consumption, efficiency, and exhaust opacity, are compared with those obtained fuelling with Diesel fuel.

Mixed-Potential NOx and NH3 Sensors Fabricated by Commercial Manufacturing Methods

Meeting EPA Tier 3 emissions reduction requirements while simultaneously increasing fuel economy to meet new CAFE standards will require optimization of advanced combustion strategies and emissions control technologies. There is an immediate need for suitable exhaust gas sensor technologies to monitor internal combustion engine tailpipe emissions and to control and maintain efficient operation of the engine and exhaust after treatment systems. NH3, NOx, and HC sensors could enable onboard diagnostics and combustion control in lean-burn engines, analogous to the role of O2 sensors in stoichiometric burn engines. Commercial manufacturing methods have been used to fabricate self-heated mixed-potential sensors in a planar automotive configuration. By altering materials composition and operating conditions, we are able to obtain sensitivity/selectivity to each NH3, NOx and HCs. Additionally, these devices exhibit stable performance over months of testing as a result of the stable morphology of the electrode/electrolyte/gas three-phase interface.