CFD Analysis Of Intake Flow In The L-Head Engine

The CNG fuel engine usually had lower performance comparing to gasoline fuel. A small single cylinder engine (L-head engine) is used in Green Technology Vehicle laboratory (GTeV) lab, which is low cost and commonly available in the market. It is difficult to experimentally to track the particle in 3D cases. Therefore, commercial numerical simulation is used. This thesis analysed the behaviour of the flow inside L-head combustion chamber for in-cylinder engine without the combustion with three different models were simulated. The objectives are to develop numerical model, to investigate the flow without combustion, to analyse flow with CNG and gasoline and to perform validation on the pressure between experiment and simulation. There are three types of simulation; steady, Port-flow and Cold-flow. The engine parameters and valve lift are measured, and the engine head were scan using ezScan 4.5 software. All of the simulations are simulated using ANSYS software. Only intake stroke is simulated for steady simulation with different crank angle and engine speed. Port-flow simulation is only simulated at intake stroke with introduction of CNG and gasoline as a fuel and three different valve lift. Cold-flow simulated a full cycle engine without combustion process. The Steady simulation is dealing with the static domain. There are only combustion chambers and piston volume involved in the steady simulation. The air inlet velocity was calculated using the standard engine formula for different piston position. The second simulation, Port-flow simulation also deals with the static geometry domain. Inplenum and outplenum was added by the presence of both intake and exhaust valve for the Port flow simulation domain. Three different valve lift was chosen. Gasoline and CNG were used as fuel, which enters the domain through the fuel intake. The last simulation is called Cold-flow where the geometry is moving according to the crank angle. The intake valve and exhaust valve are moving according to the measured valve profile. Meanwhile the piston movement was generated according to the crank angle of the engine. The result of steady flow simulation shows the velocity is high when the piston position is at 45° and engine speed of 4500 rpm. The result of Port-flow simulation shows the mass flow rate and velocity across the domain increase as the valve lift increase. The pressure difference between the intake port and combustion chamber decrease as valve lift increase. The swirl ratio decreases as going down the cylinder. The Cold-flow result shows the turbulence kinetic energy, swirl, tumble, and cross-tumble ratio inside the combustion chamber increase in the middle of the intake stroke. The temperature inside combustion chamber is increasing as the piston reaches TDC due to compression process. The result of Cold-flow simulation is validated by experiment without combustion with 22.73% of percentage difference at peak pressure. The combustion chamber head has been scanned and imported to ANSYS software. The velocity is highest when the piston located at the middle of the stroke and lowest then the piston approaching TDC and BDC. The flow pattern of gasoline and CNG has no significant change. The pressure for experiment and Cold-flow simulation is validated through its pressure pattern

Development Of Numerical Model For Simulation Intake Flow In Combustion Chamber Of L-Head Engine Type

Flow inside the combustion chamber plays the main role in the combustion process. This paper analyzed the behavior of the flow inside the L-type combustion chamber for in-cylinder engine with three different simulations. The first simulation is dealing with the static geometry of the domain. There are only combustion chambers and piston volume involved in the static simulation. The air inlet velocity is calculated using the standard engine formula for the piston at position of 9°, 18°, 27°, 36°, and 45° degrees after the top dead center. Engine speed ranges from 1500 rpm to 4500 rpm with increment of 500 rpm. The second simulation called port-flow simulation also deals with the static geometry domain but there is an addition at the intake port and intake valve. The piston volume is set to be at highest volume. There are three different valve lift used. The inplanum pressure is set to the environment pressure and the outplanum pressure is set according to the chosen values

INTAKE ANALYSIS ON FOUR-STROKE ENGINE USING CFD

Flow patterns are vital to ensure that the engine can produce high performance with the presence of swirl and tumble inside the cylinder. In this paper, the simulation of air is simulated in the software to predict the flow pattern using the steady state pressure based solver at two different planes in the engine domain. The domain used for the simulation is based on the actual engine parameters. Using the commercial CFD solver ANSYS FLUENT, the CFD simulation is run under five different piston positions and seven different engine speeds. Note that in this simulation, only intake strokes are simulated. The results show the velocity of the flow is high during the sweep as the intake stroke takes place. This situation is believed to produce more swirl and tumble during the compression, hence enhancing the burning rate in an entire region of the clearance volume. The result shows that both for plane A-A and plane B-B, the highest velocity vector occurs when the engine speed at 4500 rpm with piston position at 45 degree. This will initiate to the production of tumble and swirl in the engine cylinder

Performance Analysis Of A Spark Ignition Engine Using Compressed Natural Gas (CNG) As Fuel

Compress natural gas (CNG) is also considered as alternative fuel to produce better emission in a vehicle, but the main disadvantage of CNG in comparison to liquid fuel (gasoline) is the lack of power produced for the same capacity of engine. In this study, the single cylinder spark ignition (SI) engine was selected in order to study the effect CNG into the spark ignition engine. The hydraulic dynamometer was used to study the performance of CNG and liquid fuel. The usage of sensor also applies to the test to extract the data during the ignition stage for liquid fuel and CNG. The heat generated by both types of fuel also had been extracted from the tested engine in order to define which usage of fuel would cause a higher heat transfer to the engine. From this study, the result showed that pressure inside cylinder for CNG is 20% less than gasoline. CNG fuel also produced 23% less heat transfer rate compared to gasoline. The results explained why CNG produced 18.5% lower power compared to liquid fuel (gasoline).So, some improvement needs to be done in order to use CNG as fuel

Simulation of Single Cylinder Engine Fuel with Alternative Fuel by Using Available Software

Simulation study which is one-dimensional by using available software (GT-Power) was used to study the performance of single cylinder engine with different types of fuel source. In this study, two different types of fuel were used which are gasoline and natural gas. The simulation was run based on model built in GT-Power and the model was validated by measurement from the real engine