This paper addresses the issue of metrological accuracy of instantaneous in-cylinder pressure measurement in a diesel engine test bed. In studies, the central unit has been the single-cylinder AVL 5402 engine. The pressure measurement was performed with a sensor designed for thermodynamic analysis, and the results were related to the crank angle, where two rotations corresponding to the four-stroke working cycle were denoted as angles between −360° and +360°. The novelty of this paper is the proposition of how to perform a type A uncertainty estimation of the in-cylinder pressure measurement and to assess its repeatability. It was demonstrated that repeatability of the measurement during the ignition process was difficult to estimate because of the phenomena that cannot ensure the repeatability conditions. To solve the problem, two methods were proposed. In one method, the pressure was measured in the subsequent cycles immediately after the ignition was turned off, and in another method, the engine was driven by a starter. The latter method provided maximal pressure values much lower than during usual tests. The obtained repeatability of measured pressure was %EV = 0.4%, which proved high capability of the evaluated measurement system.

The paper presents some research results to recognize the possibility of realization of the idea of a multi-fuel IC engine. Future construction is planned as a flexible solution for military or special purpose transport means and emergency power generation. The proposed engine would utilize compression ignition mode for combustion of high reactive fuels (JP-8, diesel oil, etc.) or spark ignition mode for gasoline or other low reactive fuels. Practical implementation of the idea requires that highly reactive fuels be burned efficiently at a low compression ratio suitable for both engine modes. For the test diesel oil, JP-8 and its blends with pure rapeseed oil were chosen as easily accessible fuels. The experiment was carried out on naturally aspirated and supercharged AVL research engine with a common rail system and compression ratio CR = 12. The elaborated, unified injection strategy that synchronized the main dose injection timing with the start of the second stage of homogeneous mixture combustion was checked in practice. The proposed injection strategy applied for CI engine with the low compression ratio enabled efficient combustion and comparable, relatively high engine performance for all tested fuels.

Jet Propellant-8 (JP-8) is used as a fuel for a standard Compression Ignition (CI) engine instead of diesel oil, especially in the military applications. The properties of a kerosene-type fuel, which is JP-8, encourage us to test different strategies of mixture creation and combustion which could...

The paper describes the effect of dual fuelling of single cylinder AVL test CI engine with the use of two ways of gas delivery to the engine manifold. The engine was fuelled diesel oil and propane. For all the tests, gas consumption was maintained at the same level. In the first mode the gas was delivered by injector located under inlet valve. In the second method, there was used a mixer fitted to the intake manifold. The paper compares the results of thermal efficiency and emissions of propane in the exhaust for both fuelling modes. Research clearly show how important it is to synchronize the injector opening time of the intake stroke. This is especially important for supercharged engines in which there is a valve overlap.

This paper investigates an impact of the exhaust gas recirculation on concentration of selected harmful chemical compounds from the AVL 5402 research diesel engine powered with diesel fuel (DF) and compressed natural gas (CNG). In particular the engine was operated in the dual fuel mode. It means...

For many years in the Department of Automobiles and Internal Combustion Engines at Kazimierz Pulaski University of Technology and Humanities in Radom there are carried out investigations on dual-fuel combustion system in a compression ignition engine. The majority of literature reviews, as well as the authors' studies were limited to the older generation engines, i.e. naturally aspirated engines that are not equipped with the exhaust gas recirculation system. The paper presents results of investigations on a turbocharged engine equipped with an EGR system. The authors tried to assess the effect of the recirculation ratio on engine performances (mainly the mean effective pressure and the engine overall efficiency as well as exhaust emissions). The obtained results indicate that it is possible to apply high energy shares of the gaseous fuel maintaining at the same time high engine overall efficiency and visibly reducing the particulate matter emission. It was also noticed that the NOx emission may be visibly reduced introducing the exhaust gas recirculation system. Unfortunately, an increase of the gaseous fuel energy share results in slightly higher hydrocarbon and carbon monoxide emissions.