Prediction of Road Accident Risk for Vehicle Fleet Based on Statistically Processed Tire Wear Model

The goal of the paper is to investigate the impact of tire tread depth on road accident risk and to develop an accident rate prediction model. The state of 4288 vehicle tires using tread depth gauge was inspected and processed statistically. The tread depth of the most worn tire from each vehicle was registered for further analysis. Based on the collected data, a statistical tire tread depth model for an insurance company vehicle fleet had been developed. The conformity of the gamma distribution to the data was verified upon applying the Pearson compatibility criterion. The paper provides the histograms of the frequencies of tire tread depths and the theoretical curves of the distribution density. The probability of the accident risk depending on the tire tread depth (adaptive risk index) was calculated applying the formed distributions and risk index dependence on the tire tread depth for the inspected vehicle fleet. According to the developed prediction model, an upgrade of the regulation for the minimum allowed tire tread depth by 2 mm (up to 3.6 mm) could reduce road accident risk (caused by poor adhesion to road surface) to 19.3% for the chosen vehicle fleet. Such models are useful for road safety experts, insurance companies and accident cost evaluation specialists by predicting expenses related to insurance events

Ecological aspects of using biological diesel oil in railway transport

The number of various transport facilities used in Europe is rapidly growing. They release a big amount of pollutants into the atmosphere. Therefore, environment protection from these pollutants ejected by internal combustion engines is a key problem facing us today and which will be acute in the future. Biofuel is the only effective and widely used alternative fuel which can reduce pollution of the environment. The main aim of the present paper is to perform a comparative analysis of burnt gases of engines using rapeseed oil methyl ester and petroleum diesel oil and to determine ecological effectiveness of biofuel used in diesel locomotive engines in railway transport. First published online: 27 Oct 201

The influence of turpentine additive on the ecological parameters of diesel engines

After Lithuania's accession to the EU it is very important to use a larger amount of renewable fuel. Based on economic and environmental considerations in Lithuania, we are interested in studying the effects of turpentine contents in the blended turpentine‐diesel fuel on the engine performance and pollutant emission of compression ignition (CI) engine. Therefore, we used engine test facilities to investigate the effects on the engine performance and pollutant emission of 5 % turpentine in the fuel blend. The tests were carried out in the laboratory on an engine dynamometer of the car Audi 1Z and tractor D21 diesel engines. The experimental results showed that turpentine used in the fuel blend for these diesel engines had a positive influence on the engine performance and exhaust emission. First Published Online: 27 Oct 201

The economic effect of using biological diesel oil on railway transport

The tests performed by the authors have shown that diesel locomotive engines efficiently operate using a mixture of diesel oil and about 40% of rapeseed oil methyl ester (RME) while their ecological and economical parameters do not differ much from those of the locomotives operating on pure diesel oil. When biodiesel is used, the pollutants released into the atmosphere by an engine are less harmful. Therefore, the respective laws of the Republic of Lithuania provide for some financial incentives and allowances to transport enterprises using biological diesel oil. The paper presents a mathematical model for determining the expenses associated with the use of biological diesel oil. First published online: 27 Oct 201

Betterment of ecological parameters of a diesel engine using Brown‘s gas

Hydrogen could become an important element, allowing us to accumulate and transfer energy in a clean way. Hydrogen can be used in cars as a fuel additive which increases the combustion efficiency of the fuel-air mixture. A small amount of hydrogen gas could also be produced in a car by decomposing water by means of electrolysis, using for this purpose the energy produced by the car's electric power generator. The hydrogen and oxygen (HHO) mixture obtained, which is also known as Brown's gaseous mixture, is supplied to the engine's intake manifold. Tests have been performed with 1.6 TD (SB) diesel engine. The automobile was tested on a chassis dynamometer running at a different speed. The engine was tested using fuel-air combustion mixture and fuel-air-HHO gas combustion mixture without additional adjustment of the fuel supply system. The test results have revealed that additional injection of HHO gas into combustion mixture resulted in up increase of fuel consumption, but the CO, the HC, the PM amount has decreased insignificantly. At few engine loads the amount of NOx decreased, however increasing the engine load resulted in a gradual increase. Having analysed test results we came to a conclusion that additional supply of HHO gas into combustion mixture resulted in improvement of the combustion quality of fuel-air mixture and ecological performance of the engine. This is especially relevant for the automobiles which are not equipped with a supplementary exhaust gas toxicity decreasing system. First published online: 11 Oct 201

Analysis of exhaust gas composition of internal combustion engines using liquefied petroleum gas

The problems of implementation of liquefied petroleum gas (LPG) supply systems are related with the fact that they are alternative systems used in engines constructed and optimized for work with other kinds of fuel. So assemblers of the systems have to evaluate power losses and at the same time ecological requirements. The experiment is devoted to the analysis of gas composition of engines working at different modes in order to specify the particularity of LPG system tuning and to obtain data for the evaluation of environmental pollution by numerical car dynamics models. It is estimated that the algorithms of current LPG systems balance between ecological requirements and optimization of external characteristics of engines, and the gas systems are characterized by a great inertia. Also, it is determined that more precise tuning algorithms must be constructed, and more tuning points and tuning, when an engine works in standard modes, must be foreseen. Vidaus degimo variklio, varomo suskystintosiomis dujomis, išmetamųjų dujų sudėties tyrimas Santrauka Naudojant suskystintųjų dujų sistemas automobiliuose, pritaikytuose veikti benzinu, susiduriama su įvairiomis, aplinkos taršos problemomis. Todėl sistemų montuotojai turi įvertinti ne tik galios nuostolius, bet ir kaip tos sistemos atitinka ekologinius reikalavimus. Eksperimentuojant siekta ištirti variklio, veikiančio įvairiais režimais, išmetamųjų dujų sudėtį, nustatyti tokios sistemos derinimo ypatumus ir gauti ekologinės taršos vertinimo duomenis analizuojant automobilio skaitmeninius dinaminius modelius. Nustatyta, kad būtina sudaryti tikslesnius suskystintųjų dujų sistemų reguliavimo algoritmus, numatyti daugiau derinimo taškų ir derinti variklį apkrovus, jam veikiant tipiniais režimais. Firstd Published Online: 14 Oct 2010 Reikšminiai žodžiai: išorinė vidaus degimo variklio charakteristika, suskystintosios dujos, aplinkos tarša, išmetamosios dujos

Comparative investigations into energetic and ecological parameters of camelina-based biofuel used in the 1Z diesel engine

The paper presents the findings of comparative investigations into the operation of Audi 80 1.9l 4 cylinder diesel engine, TDI, type 1Z, 66 kW powered by new FAME (fatty acid methyl esters) mixtures of spring (SCME) and winter (WCME) camelina-based biofuel and mineral diesel. The article assesses the principles of operating electronic control over the diesel engine (ECS) and exhaust gas recirculation (EGR) and looks at a positive impact of the system on energetic (be, ηe) and ecological (CH, NOx, CO2, SM) parameters. The ECS of the average and maximal power of the engine improve in-cylinder air injection that has an impact on an increase in ηe by approximately 30% and reduces the emission of the harmful components from incomplete combustion. It is accepted that in case diesel fuel is replaced by FAME biofuels (RME – rapeseed methyl ester; SCME – spring camelina methyl ester; WCME – winter camelina methyl ester), ECS control parameters shall not be retrofitted or additionally optimized. The properties of camelina-based biofuel mixtures B30 (SCME) and B30 (WCME) and diesel fuel are similar to the properties of the standard mixtures of RME biofuel B30 (RME). If compared to diesel fuel, the use of camelina-based biofuel mixtures B30 (SCME) and B30 (WCME) enables lower emissions of harmful components from exhaust gases, which makes approximately 15% of CH and 20÷25% of SM

INVESTIGATION OF COMBUSTION, PERFORMANCE AND EMISSION CHARACTERISTICS OF SPARK IGNITION ENGINE FUELLED WITH BUTHANOL – GASOLINE MIXTURE AND A HYDROGEN ENRICHED AIR

In this study, spark ignition engine fuelled with buthanol-gasoline mixture and a hydrogen-enriched air was investigated. Engine performance, emissions and combustion characteristics were investigated with different buthanol (10% and 20% by volume) gasoline mixtures and additionally supplied oxygen and hydrogen (HHO) gas mixture (3.6 l/min) in the sucked air. Hydrogen, which is in the HHO gas, improves gasoline and gasoline-buthanol mixture combustion, increases indicated pressure during combustion phase and decreases effective specific fuel consumption. Buthanol addition decreases the rate of heat release, the combustion temperature and pressure are lower which have an influence on lower nitrous oxide (NOx) emission in exhaust gases. Buthanol lowers hydrocarbon (HC) formation, but it increases carbon monoxide (CO) concentration and fuel consumption. Combustion process analysis was carried out using AVL BOOST software. Experimental research and combustion process numerical simulation showed that using balanced buthanol and hydrogen addition, optimal efficient and ecological parameters could be achieved when engine is working with optimal spark timing, as it would work on gasoline fuel

The methodology for calculation of road accident costs

The presented methodology for accounting the costs caused by road accidents is based on the fact that a person who died or was injured in a traffic accident will not contribute to the economic wealfare of the country anymore or his/her contribution will reduce. Broken vehicles, damaged cargoes or defected road constructions cause huge losses to the state. A financial assessment of material losses caused by road accidents enables providing a feasibility report in respect of efficiency of newly introduced traffic safety measures. The aim of the presented methodology is an establishment of the road accident costs that would conform to the todays economic level of Lithuania. The developed methodology for accounting road accident costs will enable more precise assessment of a necessity, perspectives and priorities of investment projects in the transport system as well as an accomplishment of funding allocation tasks

Dependence of evaporation losses on petrol quality

The paper deals with the interrelation between evaporation losses and automobile petrol quality and presents the results of research on modern petrol. It has been established that evaporation leads to an increase in heavy hydrocarbon concentration in petrol composition adversely affecting its quality and operational properties at the excess of permissible concentration. First published online: 10 Feb 201