Week 1- Mixing Tee
Mixing Tee
Description:
Mixing tee is a flow control devices.It mixes the two different fluid stream into a combined fluid stream.In has two inlets and one outlet.In this two inlets, one is located along the X axis and the other is located along the Y axis.The outlet is located along the X axis.
Formula:
momentum ratio = velocity at cold inlet/velocity at hot inlet.
Steps in analysis of Mixing Tee:
- Geometry
- Meshing
- Set up
- Solution
- Result
Case 1: Shorter Mixing Tee
- Velocity at hot inlet =3 m/s
- Temperature at hot inlet=25C
- Temperature at cold inlet=10C
- Momentum ratio=2
Geometry:
1.Importing the model.
2.Fluid volume extraction.
3.Suppress for physics.
1.Importing the model:
The first step in this case is importing the solid Tee model to the space claim.
2.Fluid volume extraction:
Volume extraction is defined as extracting the volume phase from the solid geometry. Here the fluid volume is extracted by using the volume extraction command.
3.Suppress for physics:
Suppress for physics is a command it is used to deactivate the solid model.In this case we only requires the fluid volume so that the solid model is suppresed.
Meshing:
Meshing is the process of dividing the solid model into a small individual element.Here we are discretizing the solid model into a small element of size 0.003m.We obtained,
No of elements = 39393.
No of nodes = 8275.
After completion of meshing naming should be done. Proper naming should be given for all the faces and the quality of the each element is checked.
Element Metrics
Set up:
This is the major step in analysis because here only we gave the values and conditions of the Tee model.This case runs under the following condition,
General :1.Steady state
2.Pressure based solver
Material :1.Fluid-Air
2.Solid-Aluminium
Model :1.K epsilon -standard K epsilon-standard wall function
Cell zone condition :Volume-Fluid-Air
Boundary condition:1.Inlet X- Velocity inlet-3m/s
2.Inlet Y- Velocity inlet-6m/s
Initialization :Hybrid initialization
After intialization a plane has to be created normal to the Z axis. The temperature and velocity of the Tee is analysed in the plane and average temperature at the outlet is to be calculated.Finally the calculation is to be runned for 600 iterations.
Solution:
The calculation is converged in the 200 iterations.
Result:
Temperature Contour :
Velocity Contour:
Case 2: Long Mixing Tee
- Velocity at hot inlet= 3m/s
- Temperature at hot inlet=25C
- Temperature at cold inlet=10C
- Momentuem ratio=2
Geometry:
The long Tee model is imported in the space claim.The fluid volume is extracted and the solid model is suppressed.
Meshing:
The long Tee model is discretized into a small individual elements of size 0.003m.
No of elements:56269.
No of nodes :11664.
Element Metrics:
Set up:
General :1.Steady state
2.Pressure based solver
Material :1.Fluid-Air
2.Solid-Aluminium
Model :1.K epsilon-standard K epsilon-standard wall function
Cell zone condition :Volume-Fluid-Air
Boundary condition:1.Inlet X-velocity inlet-3m/s
2.Inlet Y-velocity inlet-6m/s
Initialization :Hybrid initialization
Solution:
The calculation is converged in 170 iterations.
Result:
Temperature Contour:
Velocity Contour:
Case 3:Shorter Mixing Tee
- Velocity at hot inlet=3m/s
- Temperature at hot inlet=25C
- Temperature at cold inlet=10C
- Momentum ration=4
Geometry:
The shorter Tee model is imported.The fluid volume is extracted and the solid model is suppressed.
Meshing:
The solid Tee model is discretized into a small elements of size 0.003
No of elements = 39393.
No of nodes = 8275.
Element Metrics:
Set up:
General :1.Steady state
2.Pressure based solver
Material :1.Fluid-Air
2.Solid-Aluminium
Model :K epsilon-standard K epsilon-standard wall function
Cell zone condition :Volume-Air
Boundary Condition :1.Inlet X -velocity inlet-3m/s
2.Inlet y -velocity inlet-12m/s
Initialization :Hybrid initialization
Solution:
The calculation is converged in 150 iterations.
Result:
Temperature Contour:
Velocity
Velocity Contour:
Conclusion:
In case 1 the momentum ratio is only 2 so that the ratio of the hot velocity and cold