A. Nieoczym

Analysis of Unrepeatability of an SI Engine Based on Measurements of Indicated Pressure

The article presents the results of an empirical study of unrepeatability of the spark-ignition engine BMW N43 B20 AY, which uses a spray-guided gasoline direct injection system to create the fuel mixture. The values of the so-called unrepeatability index of maximum indicated pressure were analyzed for two different engine operating conditions: under maximum load (absolute throttle at 91%) and under partial load (absolute throttle at 33%). The values of the index were calculated on the basis of values of indicated pressure recorded over 100-cycles at five predefined rotational speeds of the engine crankshaft. It was found that the unrepeatability of maximum indicated pressure during operation of the test engine was lower under partial load than under maximum load.

Finite Elements Strenght Analysis of a Compressor Consisting of Four Helical Rotors

The present article reports the results of tests of a compressor consisting of four helical rotors. Finite element strength analysis of rotors with varied screw thread pitch was performed. The analysis allowed us to determine the stress-strain state of the rotor material and deformation of rotors as an effect of loads generated during operation of the compressor. The analysis also made it possible to calculate the frequencies of the free vibrations of the rotors.

Analysis of tank safety with propane-butane on LPG distribution station

Abstract An analysis of the risk of failure in the safety valve – tank with propane-butane (LPG) system has been conducted. An uncontrolled outflow of liquid LPG, caused by a failure of the above mentioned system has been considered as a threat. The main research goal of the study is the hazardous analysis of propane-butane gas outflow for the safety valve – LPG tank system. The additional goal is the development of an useful method to fast identify the hazard of a mismatched safety valve. The results of the research analysis have confirmed that safety valves are basic protection of the installation (tank) against failures that can lead to loss of life, material damage and further undesired costs of their unreliability. That is why a new, professional computer program has been created that allows for the selection of safety valves or for the verification of a safety valve selection in installations where any technical or technological changes have been made.

Experimental Data in Vehicle Modeling

Abstract This article is about a vehicle model which is created in software Matlab Simscape Driveline. In this model the motor is created like a subsystem by Simulink blocks and input data were measured by single roller dynamometer for cars (SRD). Measured data are the input into the model by Lookup Table block. The vehicle model is made by gear, differential, tire and vehicle body blocks. We studied the forces on tires, the vehicle velocity and the slip.

Experimental tests on a dual fuel compression-ignition engine powered by biogas with a varying chemical composition

Biogas is among the fuels whose significance in the general energy balance will increase. These results from the fact that it may be produced from various kinds of waste materials, and it is therefore considered a renewable fuel of the second generation. Because of its properties, biogas may be used directly to power spark-ignition engines. Nonetheless, numerous tests are underway involving the possibility of using biogas to power compression-ignition engines. In order to use biogas, whose main combustible component is methane, in compression-ignition engines, it is necessary to use a dual fuel power supply system. With such a system supplying power to the engine, the gas and air mixture in the cylinder is ignited by a small dose of liquid fuel. This paper presents a fragment of the research on the use of biogas with a varying chemical composition for powering compression-ignition engines. The described tests were conducted using a one-cylinder compressionignition engine mounted on an engine test stand. The fuel gas consisted of a mixture of natural gas and carbon dioxide; the share of each individual component was regulated from the station, which controlled the operation of the whole test stand. The developed control system also enabled the adjustment of the operating parameters of the engine test stand and the parameters of the injection of liquid fuel, such as the injection pressure, the timing angle of injection and the size of the dose. The results presented in the paper show the impact of the individual control parameters of the engine on the value of the engine’s torque and the amount of toxic compounds in the exhaust fumes.