No-hydro simulation of PFI (Port fuel injection) Engine in CONVERGE CFD

Title: No-hydro simulation by Surface preparation & boundry flagging in CONVERGE CFD

Objective : 1. To Understand the boundry flagging & surface preparation on PFI 

                   2. To perform the No-Hydro simulation of PFI Engine

                   3. To undestand the error came across & explain meaning of each error 

 

Theory: 

              4-stroke PFI (Port fuel inection) model is given for perform the no- hydro simulation it means that there will not be any reaction only how there is mesh & parts movement is working that will be checkt it. while doing No-hydro simulation there is nedd to do boundry flagging & surface preparation during this period there are many erro come across that can be remove. so, in this challenge important part is to surface preparation & run the no hydro simulation.

3D Geometery

                  

Error occurs in geometery

                                    

Boundry name is created to remove the Errors

                            

                     

1. Liner

 fence to edge by arc method , so that we can flag the liner 

        

2.              

         

Inflow

by fence method flag the boundry

       

Outflow

                

Intake port-1 & 2

                           

Exhaust port

                   

Cylinder head

                          

Intake valve top, bottom & angle

                 

Spark plu & terminal

                  

Exhaust valve top, bottom & angle

                                        

Type of error 

1. Intersection error

This error occurs due to cylinder head is intersect with intake valve angle then there is intersection error occurs. it can remove by the transform option by the boundry type so there is select the intake top, bottom & angle. it transform by the 0.0001   

2.Open edge error

open edge error showing in yellow colour by the patch we can remove it

             

 

3.Non manifold edge error

one edge share by three or more trianle then this error occcur & it can be remove by the stich option 

                        

4.Normal orientation error

direction of normal should be inside as flow is flowing inside the PFI engine. it can point out to inside by the transform normal inside by select any one traingle

                      

CASE Setup for NO-Hydro

 1 Application type -Crank based IC Engine

           Cylinder bore=0.0856m 

            Crank raduis=0.09

           Connecting rod length=0.18

            Crank speed=3000 rpm

2.Materials

         Gas simulation>import them.dat file

         Reaction mechanism> import mech.dat

3. Simulation parameter

        Solver> Transient

         Temporal type> Crank based simulation

        Simulation mode> No-hydrodynamic

Simulation time parameter

            Start time= -480 deg

            End time= 240 deg

            Intial time step=1e-7

            Intial time step=1e-8

Boundry condtion

Outflow

 comnustion product is given CO2, N2, H20

Inflow

at inflow air quantity is flow

Liner

   Boundry type> Wall            Surface movement> fixed

   motion type>stationary      Temp > 450k           Turbulent tke> zero normal gradient

Cylinder head

    Boundry type> Wall            Surface movement> fixed

   motion type>stationary        Temp > 450k           Turbulent tke> zero normal gradient

Exhaust port

    Boundry type> Wall            Surface movement> fixed

    motion type>stationary        Temp > 500k           Turbulent tke> zero normal gradient

Exhaust valve top

     Boundry type> Wall            Surface movement>moving    profile>exhaust lift.in

     wall motion type>Translating       Temp > 525k                 Turbulent tke> zero normal gradient

Exhaust valve angle

     Boundry type> Wall            Surface movement>moving     profile>exhaust lift.in

     wall motion type>Translating       Temp > 525k           Turbulent tke> zero normal gradient

Exhaust valve bottom

     Boundry type> Wall            Surface movement>moving    profile>exhaust lift.in

     wall motion type>Translating       Temp > 525k           Turbulent tke> zero normal gradient

Intake valve bottom

     Boundry type> Wall            Surface movement>moving     profile>intake lift.in

     wall motion type>Translating       Temp > 480k           Turbulent tke> zero normal gradient

Intake valve angle

     Boundry type> Wall            Surface movement>moving     profile>intake lift.in

     wall motion type>Translating       Temp > 480k           Turbulent tke> zero normal gradient

Intake valve top

     Boundry type> Wall            Surface movement>moving     profile>intake lift.in

     wall motion type>Translating       Temp > 480k           Turbulent tke> zero normal gradient

Spark terminal

     Boundry type> Wall            Surface movement>fixed

     wall motion type>Stationary      Temp > 600k           Turbulent tke> zero normal gradient

Spark plug

     Boundry type> Wall            Surface movement>fixed

     wall motion type>Stationary      Temp > 550k           Turbulent tke> zero normal gradient

Intake port-1

     Boundry type> Wall            Surface movement>fixed

     wall motion type>Stationary      Temp > 425k           Turbulent tke> zero normal gradient

Intake port-2

     Boundry type> Wall            Surface movement>fixed

     wall motion type>Stationary      Temp > 425k           Turbulent tke> zero normal gradient

Region & Intialzation

        

Intake port-1

Intake port-2

 

exhasut port

          

Event Created

for flow the fuel from intake port-1 to cylinder region event is created, so that disconnected triangle is created & it will be broken so, that flow of fuel is start, its same for exhaust port after combustion process is over

Intake port-1 & 2 is always connected 

Base grid size= 0.008m

Fixed embedding

1. Intake valve angle                   

Fixed embedding= (base grid size)/2^n

  base grid size uses =0.008m

   n=4= scale

  Embed layer =1

  fixed embedding= 0.008/2^4

                              = 0.0005 m

              

     

Embed layer =1

  fixed embedding= 0.008/2^4

                              = 0.0005 m

Exhaust valve angle

Big Cylinder 

Embed layer =1

  fixed embedding= 0.008/2^2

                              = 0.000125 m

  

Small cylinder embedding

Embed layer =1

  fixed embedding= 0.008/2^2

                              = 0.000125 m

    

Pressure Contour

High pressure is created on exhaust port due to small area & burnt gas which result in high press

Temprature contour

Temprature is higher at exhaust port due to high pressure as well as burnt gas create high temp

Velocity contour

higher veocity at bottom & lesser velocity at intake & exhaust port

        

No hydro simulation of PFI Engine

from below video we can there is complete one cycle of power stroke is work.

               

 

Overall conclusion 

1. Understood how to remove diffrent error like intersection, open edge, normal orientation, non-manifold edge

2. Understood how to create the event , fixed embedding etc.

3. Understood how to flag the boundry for clean up geometery & remove errors

4. Understood how to make setup for sucessful run of PFI simulation