Diesel Engine Optimization via 1D Simulation: ENRP-20001 Project

Desklib provides past papers and solved assignments. This project details one-dimensional diesel engine simulation for reduced combustion.

ENRP- 20001 ENGINEERING RESEARCH PROJECT PLANNING

Contents
Introduction.................................................................................................................................................3
Background Knowledge..............................................................................................................................6
Objective.....................................................................................................................................................8
Scope...........................................................................................................................................................9
Milestones.................................................................................................................................................10
Deliverables...............................................................................................................................................11
Conclusion.................................................................................................................................................12
References.................................................................................................................................................13
2

Introduction
Diesel engine is the most important part of vehicles these days and its importance is growing
every day. For combustion and various other standards depend upon the parameters of engine
hence studying the operating parameters of engine is crucial in order to determine the
combustion of diesel and emission of gases. As the compression ratio of engine has direct effect
on the performance of engine, emission of gases and the combustion of diesel, it is important to
know how varying the compression ratio can affect these parameters. In order to achieve the
result of it, one-dimensional stimulation can be studied which is the extension of working
analysis of a cylinder. One-dimensional simulation determines the flow of fuel in intake and
exhaust track. This simulation is involved with knowing the correct flow of fuel and exchange of
fuel taking place. One-dimensional simulation provides the information about the initial
condition of intake valve. As the pollution caused by emission of harmful gases like CO2, NO,
SO etc. in increasing since internal combustion engine came into play. The pollution has been
increased further after the industrialization and commercialization. With these factors as diesel is
also growing popular as a fuel, which is highly toxic in nature. Its emission is causing adverse
and harmful effects to the surrounding and environment. There are some fuels which can be an
effective replacement of diesel such as Biofuel. Biofuel is manufactured using Soy bean or using
rapeseed. In some other countries feedstock such as cottonseed, sunflower, coconut oil or palm
oil are also used to produce Bio-fuel for effective replacement of diesel. Hence the simulation of
engine leads to reduction in diesel combustion. Diesel has always been a topic of problem in the
last years because of its scarcity and being the non-renewable resource. There has always been
research conducted to reduce the diesel consumption. One possible way of reducing it has been
achieved in this research which mailnly focuses on one-dimensional stimulation.
3

Figure 1 simulation diesel engine
(Source: Improving Diesel Engine Design With Simulation, 2019)
In engine simulation the two most important characteristics that are needed to be simulated are
the in-cylinder process and the piping system of engine, these characteristics help in developing
a procedure of performance basis. In-cylinder process is also known as scavenging. Hence
simulation considers these two factors to predict the charging performance of cylinder and
combustion of charge. These two characteristics are also dependent upon each other. The in-
cylinder process directly influences the wave action of piping system. The combustion diesel in
the cylinder is also influenced by scavenging flow of gas. Gas exchange process depends upon
the designing of exhaust system (Pdfs.semanticscholar, 2019). For the prediction at the design
stage the simulation of in-cylinder activity on the open and closed period and how they interact
with piping system, is important. The cylinder displacements are influenced by the design of
cylinder which in turn affects the dimensions of the cylinder. The displacements affect the length
and a longer stroke can take place without any difficulty. In simulating the engine basically the
two parts are focused as discussed above, the piping system of engine and the cylinder process.
First the solution was obtained by applying the graphical methods and then using computational
methods the solution was obtained. The equations used to solve the method can be either
homentropic or non-homentropic. In order to solve the non-homentropic type of equations
4

entropy changes, flow of heat, change in area need to be taken into care. Therefore diesel
engine’s displacements and compression ratio has important effect on the diesel consumption.
5

Background Knowledge
There is engine software which is based on one-dimensional modeling. This software is used to
represent the flow and the heat being transferred to the pipes. The software is used by the
manufacturing companies in order to know the components of the engine and in order to
optimize them. The software is also used to stimulate the two-stroke and four-stroke engine.
Now a days the engine simulation works on thermodynamic structure. The engine model can be
divided into various sub models so that for the each model working can be characterized. With
the help of dynamic equations flow in the pipes can be analyzed even with pipes of different
area, heat transfer rate, friction value (Serrano et. al, 2015). During the gas exchange process the
combustion chamber controls the flow of mass whereas Flame propagation model controls the
burn rate in combustion process. During the scavenging process, the amount of fresh charge
escaping the exhaust port is used to determine the scavenging characteristics. In simulating the
engine basically the two parts are focused as discussed above, the piping system of engine and
the cylinder process.
Wave Action in piping system
Partial differentiation equations are used to describe the one dimensional engine flow. Using the
method of characteristics these equations can be resolved and to define the curves, hyperbolic
equation can be reduced. Various variables such as velocity and thermodynamic can be
continuous or discontinuous depending upon the characteristic lines, whether they are along it or
across it. For the solutions the hyperbolic equation can be solved using some differentiating
methods. In internal combustion engines if temperature within the exhaust pipes gets
discontinuous then shock can occur in the engine. Keeping all these characteristics of an engine,
simulation can be done using method of characteristics. First the solution was obtained by
applying the graphical methods and then using computational methods the solution was obtained.
The equations used to solve the method can be either homentropic or non-homentropic. In order
to solve the non-homentropic type of equations entropy changes, flow of heat, change in area
need to be taken into care. For single or multi-cylinder the same method can be used. Using this
method simulation of expansion chamber of the engine was not possible. However in 1990 the
expansion chamber and the cause of unsteady flow were analyzed. At the time of exhaust port
opening only homentropic conditions can be applied. In 1977 it became possible to detect the
unsteady flow in one dimensional engine in terms of engine characteristics such as pressure,
density and velocity. In that time procedure for analyzing these characteristics were also
developed. The conditions for simple boundary and internal flow were also analyzed in terms of
these characteristics. The procedure for combining these equations has been developed using
mesh method. In the characteristic curve the mesh points can be found as the solution points.
6

In-Cylinder Processes
In order to determine how the engine is going to perform and the combustion of diesel or any
fuel it is important to know the in-cylinder fluid motion. During the opening period the
scavenging process needs to be modeled in order to simulate the in-cylinder process. During the
closed process combustion and expansion processes needs to be modeled. In early stages the
simulation process was assumed to be based upon the engine characteristics such as volume,
pressure and temperature. These models were chosen not chosen because of dissimilarity
between the actual and experimental values. As the scavenging process also, cannot be
considered as perfect mixing or displacement process. Hence a new model named as the zonal
model was developed in which the combustion model was categorized into several other zones
such as burned charge zone, a mixing zone and fresh charge zone. In these models fresh charge
flows to the exhaust port by the shirt circuit. Each phase of scavenging was based in some
assumptions. Conservation of mass and energy has been considered as the most important part of
most of the zonal models leaving behind the flow of motion of fuels. In some model scavenging
efficiency is dependent upon the varying mass fraction flowing through exhaust port (Abdelaal
et. al, 2017).
7

Objective
The objective of this research is to find the impact of one-dimensional simulation of engine on
the diesel combustion through the cylinder displacement and compression ratio. The further aim
is to find out replacements of Diesel in order to reduce the fuel combustion.
8

Scope
Diesel has always been a topic of problem in the last years because of its scarcity and being the
non-renewable resource. There has always been research conducted to reduce the diesel
consumption. One possible way of reducing it has been achieved in this research which mailnly
focuses on one-dimensional stimulation. The other possible ways can be by replacing the diesel
with other fuels such as bio-fuels. The bio fuels are manufactured from various crops and food
waste. One such form is ethanol which can be replaced with the diesel. Its physical and chemical
property is similar to diesel to a great extent (Torres-Jimenez et. Al, 2018). The one dimensional
simulation focuses on compression ration and its effects on diesel consumption, but to achieve
the decrease in diesel consumption there is a need to replace the fuel with other fuels. Hence
biofuel can be the best alternative. The research carried out involves the modeling of one
dimensional simulation which can be further analyzed using different fuels in order to find out
the best fuel and its impact upon the compression ratio and fuel combustion rate. A tool named
as AVL is used to analyze the fuel performance during one dimensional simulation. To carry out
the test effect of some other fuels such as ethanol can be performed by changing the engine
speed to various ranges. The engine performance is based upon the factors such as volumetric
efficiency, effective pressure, thermal efficiency, air flow, specific fuel consumption and in-
cylinder pressure. Simulation model is used to identify the trends between various fuels. As the
stoichiometric ratio of air into the fuel is somewhat less than the diesel hence engine air flows at
slightly lower speed as compared to when diesel is used. One dimensional simulation engine has
the maximum efficiency when engine speed reaches 2000 rpm. The engine has to be made highly
efficient because then only the engine can run at increased speed and also can generate more
power. Hence the scope for making the one dimensional simulation of an engine is hug as there
are already various models which has already achieved the motives such as decrease in diesel
combustion. Still the scope of more is present, for this the diesel replacement is needed as there
are several other fuels as discussed above which will be good for the engine in terms of increased
power and efficiency, and also will decrease the consumption of diesel. When the consumption
of diesel will decrease it will eventually lead to less diesel combustion, which will be beneficial
for environment.
9

Milestones
Project phase Description Estimated time
Deciding the
objective of project
The brief of the objective of the project
that needs to be analyzed and achieved
during this project.
2 days
Introduction of
problem
The description of current scenario, the
importance of the project which needs to
be implemented, the advantages and
disadvantages of the project.
5 days
Background
knowledge of
problem
The description of historical information 3 days
Scope of solution
achieved
The identification of solution, how the
identified solution can be effective and
its impact and scope.
5 days
Producing the
deliverable
One engine has to be built based upon
the problems identified and their
respective solution. So that to minimize
the combustion of diesel into the engine.
15 days
Concluding the
project
The overall brief of project including the
problem statement, its background,
solution identified and its impacts.
2 days
Total days 17 days
10

Deliverables
Deliverable of this project is going to be a one-dimensional simulation engine which will reduce
the diesel combustion with the help of compression ratio and the cylinder displacement. The
engine consists of intake system, compressor, fuel injection, exhaust system, engine cylinder,
circulation system etc. the engine consists of four stroke diesel engine. The diesel model is
modeled using the GT- power software. The diesel engine has various components such as intake
system of with different data and size. The system is started with the intake valve. This software
consists of components such as air filter. The components need data in order to run the model.
This engine cylinder supports the diesel fuel in fuel injection system, exhaust system and intake
system. All the data of component is recorded into the GT-power software. The system starts
from exhaust port and gets finished into the surroundings.
Figure 2 GT power software
(Source: Gtisoft, 2019)
11

Conclusion
Diesel engine is the most important part of vehicles these days and its importance is growing
every day. For combustion and various other standards depend upon the parameters of engine
hence studying the operating parameters of engine is crucial in order to determine the
combustion of diesel and emission of gases. The pollution has been increased further after the
industrialization and commercialization. With these factors as diesel is also growing popular as a
fuel, which is highly toxic in nature. Its emission is causing adverse and harmful effects to the
surrounding and environment. There are some fuels which can be an effective replacement of
diesel such as Biofuel (Maghbouli, 2015). Hence the simulation of engine leads to reduction in
diesel combustion. In engine simulation the two most important characteristics that are needed to
be simulated are the in-cylinder process and the piping system of engine, these characteristics
help in developing a procedure of performance basis. The cylinder displacements are influenced
by the design of cylinder which in turn affects the dimensions of the cylinder. The displacements
affect the length and a longer stroke can take place without any difficulty. Therefore diesel
engine’s displacements and compression ratio has important effect on the diesel consumption.
Deliverable of this project is going to be a one-dimensional simulation engine which will reduce
the diesel combustion with the help of compression ratio and the cylinder displacement. The
engine consists of intake system, compressor, fuel injection, exhaust system, engine cylinder,
circulation system etc. the engine consists of four stroke diesel engine. The other possible ways
can be by replacing the diesel with other fuels such as bio-fuels. The bio fuels are manufactured
from various crops and food waste. One such form is ethanol which can be replaced with the
diesel. Its physical and chemical property is similar to diesel to a great extent. The one
dimensional simulation focuses on compression ration and its effects on diesel consumption, but
to achieve the decrease in diesel consumption there is a need to replace the fuel with other fuels.
Hence biofuel can be the best alternative. Still the scope of more is present, for this the diesel
replacement is needed as there are several other fuels as discussed above which will be good for
the engine in terms of increased power and efficiency, and also will decrease the consumption of
diesel. When the consumption of diesel will decrease it will eventually lead to less diesel
combustion, which will be beneficial for environment. The research carried out involves the
modeling of one dimensional simulation which can be further analyzed using different fuels in
order to find out the best fuel and its impact upon the compression ratio and fuel combustion
rate.
12