Week 1- Mixing Tee

Aim:-Mixing Tee

Objective –

• To clean the geometry and mesh it in pre-processing.

To solve the model with best solver in Ansys solver.

• To generate contour and line plots and analyse it in postprocessor.

Import Model :-

Open ANSYS workbench→Fluid Flow(Fluent)→Drag & Drop →Double Click on the Geometry,

→Go to File →open (import) model.

First Do extract the fluid volume → it is fluid contact with the particular geometry.

steps are below

Prepare →Volume Extract →Select Edges →Ctrl +select edges →click on greenncheck box ok

Hide Solid Model 

Select the Mesh And click double click in this window select the double precision and solver  nos 

4 select then start.

For selcting the Condtions follow the parameters.

IN Physics Domain→Click 3 dots og genral→select Pressure Base→Absolute→ steady and Energy→Viscosity (K-epsilion & Relizable)→ok

Add the material.in this case we are going to the air.

Assign the Boundary Conditions.window will be popup .

Assing the solving options. steps 

Solution→Definitions→New →Surface Report → Area Weighted Avarage.

selected that select the parameters.

Area Weighted  Avarage  →Fieled Variable ( Temprature)  → Face Varible ( Outlet)

Must be check on report file and report part

Hot inlet Temperature = 36 degrees
Cold inlet Temperature = 19 degrees
Hot inlet velocity = 3 m/s
Momentum ratio = 2
Cold inlet velocity = Momentum ratio*Hot inlet velocity = 6 m/s

No of itration-250

Residuals

standard K-Epsilon

 

Standard Area Weighted avarage Temprature.

Standard Devation Of Temprature.

 Temprature Distribution of the flow in the Pipe.

Short Pipe Momentum Ratio-2                                                                         Short Pipe Momentum Ratio-2

Short Pipe Momentum Ratio-4                                                                       Short Pipe Momentum Ratio-4

 

Long Pipe Momentu Ratio is 2.

Long Pipe Momentu Ratio is 4.

 

Pipe type	Momentum Ratio	Nodes	Cells/ Elements	Iterations	Temperature
Short	2	110591	576543	250	36 c
Short	4	110591	576543	250	36 c
Long	2	146953	765172	200	31.5 c
Long	4	146953	765172	200	31.6 c

Conclusion:

1. K-Epsilon converges faster and thus is also cheaper. But, both converge at some point and give similar results.
2. The temperature drop is more when the Momentum ratio is high. A possible cause is turbulent mixing. 
3. The numerical/computational solutions go hand in hand with Analytical solutions.
4. For best results, Longer pipe lengths and higher Momentum ratios can be preferred.