Adnan Parlak

Performance and exhaust emission characteristics of a lower compression ratio LHR Diesel engine

Abstract In this study, the effects of reducing the compression ratio on the performance and exhaust emissions in a low heat rejection (LHR) indirect injection Diesel engine have been experimentally compared to those obtained from a standard Diesel engine (SDE) with fixed compression ratio. Reducing the compression ratio in a SDE without making any modification in the combustion chamber geometry and improvements in fuel properties cause the ignition delay time to be unduly long, and consequently, an unacceptable pressure rise is experienced. By means of high temperature increases in the combustion chamber of the LHR Diesel engine, the compression ratio was lowered from 18.20 to 16.10 in 0.7 intervals. Satisfactory performance was obtained at compression ratios of 17.50 and 16.80 in the LHR engine. In comparison to the SDE, at these compression ratios, the specific fuel consumption and NO x emissions are, respectively, decreased about 2.9% and 15%.

Determination of the optimum temperatures and mass ratios of steam injected into turbocharged internal combustion engines

Water injection method into the internal combustion engines is commonly used to improve performance and emissions. However, condensed water causes to deteriorate the lubrication oil, in-cylinder corrosion is carried out and also wear rate of moving parts of engine increases. In order to prevent this bad effect of condensed water, steam injection is proposed. Electronically controlled steam injected method has been used for naturally aspirated engines and successful results have been obtained in terms of performance and NOx emissions. However, supercharged engine systems are used in practical life. In this study, steam injection method is developed for turbocharged systems. The optimum temperatures and mass ratios are determined based on thermo dynamical analyses.

Application of Taguchi’s methods to investigate factors affecting emissions of a diesel engine running with tobacco oil seed methyl ester

Different kinds of vegetable oils and their methyl/ethyl esters have been tested in diesel engines. However, studies reporting the effects of tobacco seed oil and Tobacco Seed Oil Methyl Ester (TSOME) on emissions of diesel engines are limited. One of the most important issues is to investigate parameters that affect the yield of biodiesel and their interactions on emissions of a diesel engine. The Taguchi method is a useful tool for this purpose. Two different catalysts (KOH and NaOH), four different blends (B10, B20, B50 and B100) and four engine speeds were used during full-load tests. Optimal catalyst type, engine speed and TSOME blends on exhaust emissions were determined using Taguchis technique. The Taguchi design method revealed that choosing right catalyst and the blend rate are important two factors in view of minimisation of pollutant emissions.

First and second law analysis of a gasoline engine for various compression ratios

This article presents a comparative energy and exergy analyses of a single cylinder, four-stroke spark-ignition engine for three compression ratios. A Petter engine with variable compression ratio and ignition timing was used to obtain the experimental data at full load conditions for six engine speeds between 1,300 and 2,800 rpm. It was found that the first and the second law efficiencies increased with increasing compression ratio. The maximum extractable power was obtained at the compression ratio 6.2 and observed inversely proportional to the compression ratio.