Modelling and simulation of flow through a flow bench

Abstract :

here first I found which grid test is give the better result of flow simulation. Then I perform the flow bench simulation for spiral inlet and show the effect on swirl generation in cylinder. How flow trejectories look like and how velocity profile change with valve lift.

specification :

Diameter of cylinder : 5 cm

length of cylinder : 10 cm

diameter of inlet port : 2.5 cm

spiral dimension and valve dimension are arbitary.

geometry of cylinder and inlet :

Procedure :

create cylinder geometry as per dimension, take valve and spiral dimension arbitry.

Create a new wizard, take air as fluid.

specify inlet boundary condition as total pressure(1.013 bar) and outlet boundary condition as static pressure(0.5 bar).

Run the simulation for different global mesh and local mesh, get the best grid which gives sophisticated result, then make that mesh constant and run parametric study for different valve lift.

Base line simulation for different mesh:

Test 1 :

Global mesh = 5, local mesh = 6

velocity profile :

flow trejectory result :

Test 2 :

Global mesh = 5 , Local mesh = 5

velocity profile :

flow trajectory result :

Test 3 :

Global mesh = 3, Local mesh = 3,

velocity profile :

flow trajectory result :

Here In the last test 3, I got best swirl generation in the flow trajectory and in the velocity profile. I got best output with global mesh 3, and further with this mesh I will perform parametric study for different valve lift.

Result of parametric study :

link for velocity profile of front view :

https://drive.google.com/open?id=14d1zC5BRTP-0UiCSGfKz9IX3FLm_ys2m

link for velocity profile of top view :

https://drive.google.com/open?id=1DJ1KzWAzl0sBSWr0USzfzlTcVDygbywn

link for flow trajectory results :

https://drive.google.com/open?id=1lSN7jfy_M9mm4T3wWNUjGTI6EunZ85q2

velocity profile sample : result from design point 4

flow trajectory result of design point 4 :

mass flow rate and valve lift result in tabular form :

conclusion :

From the graph its shows that as valve lift is increases mass flow rate increases and velocity is also increases near to valve upper part.

Here I provide spiral inlet, its help to generate the swirl and it can see in to the flow trajectory result we can so swirl inside cylinder in spiral shape.

As our swirl are increases inside cylinder, its usedto produce better mixing of fuel and air in side cylinder. By this proper mixing we got better combustion efficiency.

Thank you.