scholarly journals A model of the IC engine in the form of the bond graph (BG)

2004 ◽  
Vol 119 (2) ◽  
pp. 40-47
Author(s):  
Marian CICHY ◽  
Jacek KROPIWNICKI ◽  
Sławomir MAKOWSKI

Grounds for the use of the bond graph method in the modeling of internal combustion (IC) engines, which are energy sources in systems consisting of different physical nature elements have been presented. The model of hybrid vehicle, as an example of such system, has been presented. Examples of definitions of the main engine parameters, which follow the established BG convention have been given. A proposal of formalization of the IC engine characteristics, which follows the selected method of modeling, has been presented as well as an analytic form of the characteristic as the multidimensional vector function. Example of the engine characteristic approximation with the use of the “Spline” functions and author’s computer programs has been given.

Author(s):  
Ludeˇk Pohorˇelsky´ ◽  
Pranav Sane´ ◽  
Tomas Rozsas ◽  
Norbert Mu¨ller

This paper presents an analytical design procedure for pressure wave machines, also known as wave rotors, to enhance gas turbines and internal combustion (IC) engines in a topping or bottoming cycle. The advantage of using a wave rotor for improving the performance of gas turbines or internal combustion engines is that it uses a pressure and enthalpy exchange process. Employing pressure or even shockwaves for the energy transfer, no mechanical parts like pistons or blades are necessary inside the chamber (channel) that houses the process, which increases the air pressure delivered to the combustor of a gas turbine or cylinder of an internal combustion (IC) engine. The wave rotor has found fair success in its application to IC engines. Research and development continues for both, applications in IC engines and its originally envisioned application in gas turbines. Here an analytical 1-D algebraic wave model is realized by utilizing shockwave theory and linear gas dynamic principles to model the process in a 4-port wave rotor, with five wave reflections in the low pressure part for better gas scavenging. Using this analytical model, a comprehensive design space has been investigated and documented in performance maps. From this, conclusions and recommendations are drawn for performance and geometry optimization. The analytical algorithm has been validated using a 1-D commercial code GT-POWER and 2-D CFD code FLUENT. While here the interest is mainly in steady state operation, the analytical algorithm also models transient processes.


2012 ◽  
Vol 134 (5) ◽  
Author(s):  
Antti Hynninen ◽  
Raimo Turunen ◽  
Mats Åbom ◽  
Hans Bodén

Knowledge of the acoustic source characteristics of internal combustion engines (IC-engines) is of great importance when designing the exhaust duct system and its components to withstand the resulting dynamic loads and to reduce the exhaust noise emission. The goal of the present study is to numerically and experimentally investigate the medium speed IC-engine acoustic source characteristics, not only in the plane wave range but also in the high frequency range. The low frequency acoustic source characteristics were predicted by simulating the acoustic multiload measurements by using a one-dimensional process simulation code. The low frequency in-duct exhaust noise of a medium speed IC-engine can be quite accurately predicted. The high frequency source data is estimated by averaging the measured acoustic pressures with different methods; using the simple cross-spectra averaging method seems promising in this instance.


2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Wail Aladayleh ◽  
Ali Alahmer

This paper investigates the potential of utilizing the exhaust waste heat using an integrated mechanical device with internal combustion engine for the automobiles to increase the fuel economy, the useful power, and the environment safety. One of the ways of utilizing waste heat is to use a Stirling engine. A Stirling engine requires only an external heat source as wasted heat for its operation. Because the exhaust gas temperature may reach 200 to 700°C, Stirling engine will work effectively. The indication work, real shaft power and specific fuel consumption for Stirling engine, and the exhaust power losses for IC engine are calculated. The study shows the availability and possibility of recovery of the waste heat from internal combustion engine using Stirling engine.


2021 ◽  
pp. 1-39
Author(s):  
Bibhuti B. Sahoo ◽  
Maryom Dabi ◽  
Ujjwal K. Saha

Abstract Exergy analysis of the reciprocating internal combustion (IC) engines is studied by estimating various input and output energy transfer parameters concerning a dead state reference. Exergy terms such as fuel input, work output, cooling, and exhaust gas are measured and are set into the exergy balance equation to determine the amount of loss or destruction. Exergy destructions are found in many forms such as combustion (entropy generation), cylinder wall, friction, mixing, blow-by, and others. These exergy terms have been estimated by considering various factors such as engine type, fuel type, environmental condition, and others. In this article, the different methods employed in estimating these exergy terms have been reviewed. It attempts to make a compendium of these evaluation methods and segregates them under individual exergy terms with necessary descriptions. The fuel input measurement is mostly based on Gibb's free energy and the lower heating value, whereas its higher heating value is used during the fuel exergy calculation on a molar basis. The work output of the engines is estimated either from the crankshaft or by analyzing the cylinder pressure and volume. The exergy transfer with cooling medium and exhaust gas depends on the temperature of gas. The maximum achievable engine performance is quantified by estimating the exergy efficiency. This piece of study will not only provide a plenty of information on exergy evaluation methods of IC engines but will also allow the future researchers to adopt the appropriate one.


2021 ◽  
pp. 146808742110464
Author(s):  
Yang Hua

Ether and ester fuels can work in the existing internal combustion (IC) engine with some important advantages. This work comprehensively reviews and summarizes the literatures on ether fuels represented by DME, DEE, DBE, DGM, and DMM, and ester fuels represented by DMC and biodiesel from three aspects of properties, production and engine application, so as to prove their feasibility and prospects as alternative fuels for compression ignition (CI) and spark ignition (SI) engines. These studies cover the effects of ether and ester fuels applied in the form of single fuel, mixed fuel, dual-fuel, and multi-fuel on engine performance, combustion and emission characteristics. The evaluation indexes mainly include torque, power, BTE, BSFC, ignition delay, heat release rate, pressure rise rate, combustion duration, exhaust gas temperature, CO, HC, NOx, PM, and smoke. The results show that ethers and esters have varying degrees of impact on engine performance, combustion and emissions. They can basically improve the thermal efficiency of the engine and reduce particulate emissions, but their effects on power, fuel consumption, combustion process, and CO, HC, and NOx emissions are uncertain, which is due to the coupling of operating conditions, fuel molecular structure, in-cylinder environment and application methods. By changing the injection strategy, adjusting the EGR rate, adopting a new combustion mode, adding improvers or synergizing multiple fuels, adverse effects can be avoided and the benefits of oxygenated fuel can be maximized. Finally, some challenges faced by alternative fuels and future research directions are analyzed.


Author(s):  
George A. Adebiyi ◽  
Kalyan K. Srinivasan ◽  
Charles M. Gibson

Reciprocating IC engines are traditionally modeled as operating on air standard cycles that approximate indicator diagrams obtained in experiments on real engines. These indicator diagrams can best be approximated by the dual cycle for both gasoline and diesel engines. Analysis of air standard cycles unfortunately fails to capture second law effects such as exergy destruction due to the irreversibility of combustion. Indeed, a complete thermodynamic study of any process requires application of both the first and second laws of thermodynamics. This article gives a combined first and second law analysis of reciprocating IC engines in general with optimization of performance as primary goal. A practical dual-like cycle is assumed for the operation of a typical reciprocating IC engine and process efficiencies are assigned to allow for irreversibilities in the compression and expansion processes. The combustion process is modeled instead of being replaced simply by a heat input process to air as is common in air standard cycle analysis. The study shows that performance of the engine can indeed be optimized on the basis of geometrical design parameters such as the compression ratio as well as the air-fuel ratio used for the combustion.


Author(s):  
Qiuyu Zheng ◽  
Xu Wang ◽  
Yi Liu ◽  
Feng Jiang ◽  
Tianqi Liu

With the rapid scale expansion of the first generation of bio-liquid fuels, its impact on the prices of agricultural products, food security and the environment has begun to emerge and attracted extensive attention from governments and academia. A new multi-dimensional model of biodiesel spray combustion in an internal combustion (IC) engine is designed. Firstly, the BP neural network mining model is used to extract the spray combustion data of the IC engine. Then, based on the combustion data of biodiesel load in an internal combustion engine, burning rate and heat release, the principle of spray combustion of biodiesel is analyzed. Finally, from the two aspects of gas-phase control and liquid phase control, a multi-dimensional model of biodiesel spray combustion in IC engine is established and the spray combustion characteristics of biodiesel in IC engine are analyzed. The research results show that the model can effectively analyze the effect of load and fuel temperature on the spray combustion characteristics of biodiesel and the results of the model are almost the same as the actual data and the calculation accuracy is high. It is an effective method for studying the spray combustion characteristics of biodiesel.


Author(s):  
Helgi S. Fridriksson ◽  
Bengt Sunde´n ◽  
Jinliang Yuan ◽  
Martin Andersson

Solid oxide fuel cells (SOFCs) have the attractive feature to be able to make use of hydrocarbon fuels in their operation by reforming the fuel into pure hydrogen, either internally or externally. This can open up for a smoother transition from the existing hydro-carbon economy toward a more renewable hydrogen economy. Since both SOFCs and internal combustion (IC) engines can make use of hydrocarbon fuels, it is of interest to examine the major differences in their utilization of the hydrocarbons and investigate how this type of fuel contributes to the power output of the respective systems. Thereby, various advantages and disadvantages of their reactions are raised. It was shown that even though there are fundamental differences between SOFCs and IC engines, both types face similar problems in their designs. These problems mostly include material design and operation management, but even problems related to the chemical reactions, e.g., carbon deposition for SOFCs and pollutant formation for IC engines.


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