Week 10: Project 1 - FULL HYDRO case set up (PFI)

ASSIGNMENT NAME- FULL HYDRO case set up (PFI)

OBJECTIVE-Simulate a full hydro condition of Port fuel injection engine.

Geometry-A 3d geometry of Port fuel injection engine was imported to converge for analysis.


Setup- 
Application Type- Crank angle-based IC engine
Physical Parameters:

Bore =0.086 m
               Stroke = 0.09 m
               Connecting rod length = 0.18 m
               RPM = 3000

• Materials-
  
  Gas Simulation- The therm.dat file was uploaded to get the thermodynamic properties of the fuel.
  
  Parcel Simulation- IC8H18 was selected from predefined liquids.
  
  Reaction Mechanism 
  
  Species-Parcel IC8H18 
  
  Mesh-
  
  Run Parameters:
  Transient, Full hydrodynamic.
  
  Simulation Time Parameters:
  
  Start time : -520 deg
  end time : 120 deg
  
• Boundary Conditions:
  
  Boundary Type-WALL , Wall motion-Translating and Surface-Moving
  
  Law of wall for velocity & temperature boundary conditions
  
  Piston-Velocity-piston motion, temperature - 450K
• Exhaust valve top temperature - 525K, Exhaust lift profile is imported
  
• Exhaust valve angle temperature - 525K, Exhaust lift profile is imported
  
• Exhaust valve bottom temeprature - 525K, Exhaust lift profile is imported
  
• Intake valve top temperature - 480K, intake lift profile is imported
  
• Intake valve angle temperature - 480K, intake lift profile is imported
  
• Intake valve bottom temeprature - 480K, intake lift profile is imported
  Boundary Type-WALL , Wall motion-Stationary and Surface-Fixed
  
  
• Law of wall for velocity & temperature boundary conditions
  
  Liner temperature - 450K
  Head temperature - 450K
  Spark Plug temperature - 550K
  Spark Plug electrode temperature - 600K
  Exhaust ports temperature  - 500K
  Intake port - 1 temperature 425K
  Intake port - 2 temperature 425K
  Boundary Type-INFLOW & OUTFLOW
  
  
• Inflow pressure - 1 bar total pressure
  Inflow temperature - 363K
  Inflow species - Air
  Exhaut outflow - 1 bar
  Exhaust outlflow temperature - 800k
  Exhaust species concentration - Calculate the stoichiometric condition
  Regions and Initial conditions:
  
  
• Intake port - 1 (closer to combustion chamber)
  ic8h18 - 0.025508
  o2 - 0.20157
  n2 - 0.77292
  Temperature - 390k
  pressure - 1 bar
  
• Intake port - 2 (away from combustion chamber)
  Air
  Temperature - 370K
  Pressure - 1 bar
  Cylinder
  Pressure - 1.85731 bar
  Temperature - 1360K
  Exhaust region same as cylinder region 
  The below figure shows the different regions in the engine.
  
  
  
  Events:
  
  Cyclic event is given with exhaust and intake lift profile
  
  
  
  Permanent event is given to intake port 1 & 2 and set to open. 
  
  
  
  Physical models:
  
  Spray Modelling:
  
• Forsling model
  
  Collison model-NTC collision, collision outcomes-Post Collison outcomes
  
• Injection Parameters:
  
  Fuel flow rate = 7.5e-4 Kg/second
  Injection start time = -480.0
  Injection duration = 191.2
  Fuel temperature = 330K
  
• Rate shape implementation:

• Nozzle Positions:
  
  Nozzle diameter = 250 micro-meter
  
  Circular injection radius = Nozzle radius
  
  Spray cone angle = 10
  
  
• Nozzle 0
  centre 0.0823357 0.00100001 0.07019
  Align Vector -0.732501 0.210489 -0.647408
  
• Nozzle 1
  centre 0.0823357 -0.00099999 0.07019
  Align Vector -0.732501 -0.210489 -0.647408
  
• Nozzle 2
  centre 0.0823357 -0.0004 0.07019
  Align Vector -0.5 -0.2 -0.647408
  
• Nozzle 3
  centre 0.0823357 0.0003 0.07019
  Align Vector -0.5 0.2 -0.647408
  Combustion modelling:
  
  
  
  
  
  
• Turbulence Modelling:
  
  RANS k-epsilon RNG model 
  
  
• Spray Modelling:
  
  04 J of energy
  
  Start of spark = -15 deg
  Spark duration = 10 deg
  Spark location = -0.003 0 0.0091
  Spark radius = 0.0005m
  Grid Control:
  
  
• Base Mesh- dx=dy=dz=0.004m 
  
  Adaptive Mesh Refinement:
  
  
  
• Velocity Adaptive Mesh Refinement
  
• Temperature Adaptive Mesh Refinement:
  
  
  
  
• Fixed Embedding:
  
  Boundary Embedding
  
  
• Intake valve angle-Permanent, Scale-3, embed layers-1
  
  
• Exhaust valve angle-Permanent ,Scale-3, embed layers-1
  
  
• Cylinder Embedding-cylinder
  
  
• Big Cylinder Embedding-Permanent, Scale-1 ,0.08m
  
  
• Small Cylinder Embedding-Permanent, Scale-1 ,0.018m
  
  Spherical Embedding-
  
  Spark plug-
  
  
• Small sphere-Cyclic, Scale-5 ,start time=-16 deg ,end time=7 deg ,radius=0.001m 
  
  

Large sphere-Cyclic, Scale-3 ,start time=-16 deg ,end time=7 deg ,radius=0.003m 

Injector Embedding-



Results-

Pressure Vs Crank angle:

 

Mass of Liquid parcel present in cylinder at every crank angle:

The below graph shows the amount of liquid drops present at each crank angle.We can see that all the mass has been utilised in combustion and there is no unburnt fuel at the end.



Mass of isooctane present in cylinder at every crank angle:

The below graph shows the amount of IC8H18 present at each crank angle.We can see that all the mass has been utilised in combustion and there is no unburnt fuel at the end.



Compression ratio:

Compression ratio is the ratio of maximum volume of cylinder when the piston is at bottom dead center to the minimum volume of cylinder when the piston ia tdc.

From the below graph we can find the maximum and minimum volume of cylinder and calculate the compression ratio.


Compression ratio=`Compression ratio=Vmax/Vmin`

                                `Compression ratio=(Vc+VS)/Vc`   

                                 `Compression ratio=0.000574/(5.723*E-05)`                                 

                                 =10.02

Where Vc=clearance volume 

            Vs = swept volume

Why do we need a wall heat transfer model:

Calculate the combustion efficiency of this engine:

Combustion efficiency can be defined as the ratio of total energy released by combustion to the amount of energy contained in the fuel. The energy contained the fuel is called Lower heating value or calorific value.

The below graph indicate the integrated heat released by the combustion process.



Mass of Fuel=3e-5 kg/cycle

Lower heating value of isooctane=43.44 MJ/kg=43.44*3e-5=1303.2 J

Energy released= 1241.15 J

Combustion efficiency=energy released/LCV=1241.15/1303.2=0.952

Combustion efficiency=95.2 %

Power and torque for the engine:

From the engine performance calculator,

Speed =3000 rpm=3000/60 RPS

                             = 50 revolution/sec

                             =360*50 degree/sec

Combustion time= 240.199 degree

Combustion time in seconds=240.199/(360*50)=0.0133 s

Now,

Work=468.646 Nm

Power=work/time

Power=468.646/0.0133

Power =`(2piNT)/60`

so,   T=`(Power*60)/(2piN)`

          =112.2 W

Significance of ca10, ca50 and ca90:

ca10, ca50 and ca90 refers to the crank angle at which 10,50 and 90 percent of fuel is burnt.

From the results the value are,

ca10=6.837

ca50=18.46

ca90= 31.7

Video link:-https://www.youtube.com/watch?v=LMQ05_ve11U

Conclusion:

The full hydro condition of Port fuel injection engine was set and the simulation was run successfully.