Showing 9 results for Internal Combustion Engine
Hamidreza Tabatabaei, Masoud Boroomand, ,
Volume 11, Issue 4 (9-2011)
Abstract
Abstract- Possibilities and limitations of 1D and 3D flow simulations in the vaneless turbocharger turbine of a 1.7 liter SI engine are presented experimentally and numerically. A test setup of the turbocharged engine on dynamometer is prepared to validate the results of numerical modeling. Various performance parameters are measured at 12 different engine speeds and the results of measurement in 3 different engine speeds are presented in this report. The complete form of the volute and rotor vanes is modeled. An extensive study on the number of meshes has been undertaken to ensure the independency to meshes. The modeling of rotating wheel is considered by Multiple Rotating Frames (MRF) technique. Finally, the variations of turbine performance parameters are studied under different pulse frequencies of the engine. The results show that at high engine speeds a 3D unsteady flow simulation is required to get reasonably accurate results. The results presented in current report will be used in simulating three dimensional steady and unsteady compressible flow within the turbine of the turbocharger.
Mojtaba Abbassi,
Volume 13, Issue 12 (2-2014)
Abstract
Abstract- The comfortability of car passengers, reduction of fuel consumption in order to reduce the emission of CO2, and increasing the efficiency of fuel usage are the main goals of car manufacturers. Therefore the combustions in internal combustion engines must be done at temperatures as high as possible. These high temperatures have negative effects such as impact, rattling status in gearbox, low-pitched sound in gearbox, and vibration of vehicles. These vibrations interfere with the comfortability of passengers. In order to reduce the unwanted vibrations as much as possible there is a need to uniform the radial velocity of the flywheel and the inlet torque to the gearbox. In this study the available methods are reviewed and a new approach is proposed which is the two-mass flywheel. The effects of this new flywheel are carefully investigated. The experimental results are compared with the numerical ones and a very good conformation is observed.
Ali Nassiri-Toosi, Hossein Keshtkar,
Volume 17, Issue 10 (1-2018)
Abstract
With growing environmental pollution and concerns about fossil fuel depletion worldwide, there is an urgent need to find a solution for this problem. Using alternative fuels, such as natural gas, which can burn much cleaner than petrol or gasoline and as an advantage, it’s much cheaper than other conventional fuels and is much more widely available than oil in our planet. The most effective way we can utilize this alternative fuel in the common internal combustion engine, is by means of direct injection technology. Before natural gas can be utilized in common automotive engines, it’s necessary to conduct simulations and thus optimize these engines to maximize output power prior being built. Optimizing engines can only be achieved through simulation. KIVA-3V is a well-accepted engine simulation tool, recognized by industrial users and researchers. KIVA-3V lacks the ability to simulate gaseous fuel injections as it’s only designed to deal with liquid fuels. In this research, researched the governing equations on gas injections and used them to develop a numerical code for KIVA-3V to enable simulation of gaseous injections. We validated our modified version of KIVA-3V with two different sets of experimental data which we previously had. We showed our modified KIVA-3V code can effectively simulate gaseous injections producing very exact results. The gaseous fuel considered in this research is pure methane.
Meghdad Pishgooie, Seyed Masoud Hosseini Sarvari, Seyed Hossein Mansouri,
Volume 17, Issue 12 (2-2018)
Abstract
In this study our aim is analysis of heat transfer in an internal combustion engine. In an internal combustion engine combustion chamber all three modes of heat transfer (conduction, convection and radiation) are important and effective. - Convection and conduction problems are not as complicated as radiation problem because gases in cylinder make a participating media .in this study a solver is developed in a software which can solve combustion, heat transfer and turbulence problem simultaneously. In order to verify the solver, experimental data of a furnace is used, using the experimental data and the model the problem is solved and verified. Finally in order to study the effect of radiative heat transfer in an internal combustion engine cylinder, the simplest case is considered that is injecting a fuel jet in a simple cylinder. The model can predict thermal critical points in which pollutant form and knock phenomenon begins. Results also shows radiation heat transfer may change Temperature up to 50 percent especially in media which contains higher density of water vapor, carbon dioxide and soot.
Mohsen Agha Seyed Mirzabozorg, Saeid Kheradmand, Ali Roueini,
Volume 18, Issue 1 (3-2018)
Abstract
In this paper, a C-programming code is produced to introduce the best propulsion system including an internal combustion engine combined with turbochargers. Because the power of internal combustion engine will reduce as the altitude increasing, it is required to use one or more turbochargers in order to compensate the loss of power which is caused by reduced ambient air pressure. For this purpose, a code is written that will be able to introduce the best turbochargers combination including intercoolers, according to the target power and the desired altitude of the UAV flight. In other words, input required parameters of the code is the target power of the engine and desired altitude of flight and output of the code is number and characteristics of the turbochargers with their exact manufacturing company names and also the number of intercoolers required for best performance of propulsion system. It should be noted that, if the turbochargers that is chosen by the program are not available, user can select of the similar turbochargers with similar characteristics without any significant difference in performance of the propulsion system.
Ali Nassiri-Toosi, Sadegh Hasanpour,
Volume 18, Issue 2 (4-2018)
Abstract
In conventional internal combustion engines, about 40% of fuel energy is turned into useful power and the rest is driven by cooling and exhaust system out of the engine. Therefore, there is a ground to recover energy from this wasted energy by fixing an additional cycle inline with the exhaust gas outlet. In this research, a stirling cycle was used for this purpose. Initially, the internal combustion engine was simulated. The engine studied was an EF7-NA spark ignition internal combustion engine and the simulation results were validated by using experimental results. The results showed that the exhaust gas outlet temperature varies from 393 to 848 ° C, according to engine operating conditions. Therefore, by installing a Stirling engine heater inline with the exhaust gases from the EF7 engine, the wasted energy can be turned into useful work. To validate the results of one-dimensional Stirling engine simulation, the experimental results of the Stirling Solo V161 engine were used. After validating the Stirling engine model, the combined cycle was simulated, combining a Stirling engine at working pressure of 50, 60 and 70 bar and EF7 engine at engine speed of 2000 to 4500 rpm. The results showed that at an optimal pressure of 50 barfor the Stirling engine, the EF7 power gain was 12.2% and an average efficiency increase of 5.2%, regardless of the weight of the added stirling engine in the car which considering that, a low impact on the power of the combined cycle is expected.
Mohammad Javad Khayyami, Alireza Shateri Najaf Abadi, Mohammadmahdi Doustdar,
Volume 18, Issue 7 (11-2018)
Abstract
The purpose of this study is to investigate the effect of the simultaneous use of fuel injection injectors in an air cross flow. Nowadays, several methods are proposed for optimizing fuel injection in internal combustion engines. These optimizations are due to the high impact of this variable on engine performance and reduction of emissions. The method proposed in this study is to use two fuel injectors instead of a single injector in the air inlet manifold. The uses of two injectors in order to impingement two fuel sprays and increase the turbulent and collision of droplets, and so break them up faster. Also, the use of two injectors can provide more control over spatial and temporal distribution. Simulations are performed numerically using the generalized Kiva code. These simulations are similar to the fuel injection conditions in the manifold of the spark ignition internal combustion engine. The results indicate that the placement of two injectors in a longitudinal distance, the installation of two injectors at a 70 ° angle with the duct, placing two injectors in 180° or 90° relative angles and a 15° conical angle reduces the average diameter of the droplets. The results of this study can be used to design an internal combustion engine fuel injection system.
A. Heidary, M.a. Ehteram,
Volume 20, Issue 2 (1-2020)
Abstract
In the present paper, the performance of a shell and tube heat exchanger in which its cold working fluid is water and its hot working fluid is flue gases from natural gas-fueled internal combustion engine with working power of 15.4 kW was investigated. At first, with changing temperature and flow rate of inlet water, the performance of heat exchanger in both condensation and non-condensation situations was experimentally studied in the laboratory in order to have a criterion for validation of the simulations results in future. By comparing different simulation models in Aspen B-JAC software, the least error simulation model was chosen to do the other costly and impossible analyzes numerically in the laboratory environment. The study of the effect of the tube’s inner diameter on the heat exchanger’s performance in condensation situation showed 5.4% increase in the heat transfer while inner diameter decreases from 7 to 6 mm. The separation of the different heat transfer stages showed 26.4% of the latent heat transfer in the maximum discharge experiments for the inner diameter of 6 mm. Finally, the engine/heat exchanger set was assessed as micro combined heat and power and assumed that the heat exchanger is used for providing hot water for a 4-person family house in Tehran and the combustion engine is used for generating electrical power. This set was able to provide hot water during 9 warm months of a year by 1-hour work per day with 29% decrease of fuel consumption in comparison with traditional burners and at the same time, this set provides almost twice the electrical power requirements.
A. Amiri, M. Shojaeefard, A. Qasemian, S. Samiezaeh,
Volume 20, Issue 6 (6-2020)
Abstract
The internal combustion engine’s warm-up period is one of the most important sources of emissions, especially unburned hydrocarbons (UHC). Due to the low temperature of combustion chamber wall during the warm-up period, the flame is quenched rapidly near the walls and piston surface and the air-fuel mixture in the vicinity of the wall does not burn and leave the combustion chamber unburned which increases UHC emissions of internal combustion engines during the warm-up period. In the current study, using MATLAB R2018b software and numerical solution methods, a code is developed based on XU7 engine data to determine the effect of wall temperature on the flame quenching distance. The results showed that by increasing the cylinder wall temperature, flame quenching distance during the engine warm-up period, for two cases of constant and pressure based Peclet number, was decreased by 46 and 22%, respectively. The results also indicated that the flame quenching distance had a downward logarithmic behavior over time, which is the opposite of the thermal behavior of the combustion chamber walls during the engine warm-up period, which is an upward logarithmic behavior.
