Week 1- Mixing Tee

AIM:- To perform of steady-state simulations to compare the mixing effectiveness when the hot inlet temperature is 36⁰C & the Cold inlet is at 19⁰C creating two versions of the mixing tee.

Objective:- we have take two temperatures.

1. Hot inlet temperature = 36⁰C

2. cold inlet temperature = 19⁰C.

3. Use the k-epsilon and k-omega and sst for all cases for the more suitable results.

In this challenge we have perform the two cases

[a]. case_1:- short mixing tee with a hot inlet velocity of 3m/s and momentum ratio = 2,4

[b]. case_2:- long mixing tee with a hot inlet velocity 3m/s and momentun ratio = 2,4.

CALCULATIONS:-

MOmentum ratio = velocity at cold inlet/velocity at hot inlet

For short tee :-

momentum ratio = velocity at cold inlet/ velocity at hot inlet

2 = x/3

x = 6[velocity at cold inlet]

For momentum ratio = 4

momentum ratio = velocity at cold inlet/ velocity at hot inlet

4 = x/3

x = 12 [ velocity at cold inlet].

FOR LONG TEE:-

momentum ratio = velocity at cold inlet/ velocity at hot inlet

2 = x/3

x = 6[velocity at cold inlet]

For momentum ratio = 4

momentum ratio = velocity at cold inlet/ velocity at hot inlet

4 = x/3

x = 12 [ velocity at cold inlet].

[A]. Velocity at hot inlet = 3m/s [both cases].

[B]. velocity at cold inet = [6m/s,12m/s both cases].

1. Cell count
2. Average outlet temperature
3. Number of iterations for convergence
4. Velocity and temperature contour plots on the cut planes along and across the pipe.
5. Velocity and temperature line plots along and across the length of the pipe.
6. Perform Mesh independent study for any one case.
7. Discuss the effect of length and momentum ratio on results.

CASE:-1

SHORT MIXING TEE:- The short mixing tee with a hot inlet velocity 3m/s and momentum ratio = 2,4.

In first case we have taken momentum ratio 2 and tempertures taken 36 and 19 and velocities 3,6

GEMOETRY SECTION:- In geometry section we have import the short tee design model and extract the volumes and supress the shell section.

GEOMETRY MODEL:-

MESHING:- In meshing we have given the named selections inlet-x , inlet-y , cold inlet and walls and also generate the mesh section and find the mesh quality nodes and elements.

MESH MODEL:-

SET UP :-

1. K-EPSILON

2. SOLVER - PRESSURE BASED

3. VELOCITY FORMULATION - ABSOLUTE.

4. Time- steady state

5. viscous model - k-epsilon

6. cell zones - AIR

7. boundary conditions:- velocity maginitude = 3,3 [for both cases].x- inlet

velocity magnitude = 6 inlet-y

8. tem = 36,19 [for both cases].

set up:-

TEMEPATURE PLOT:-

[a]. cell count:- nodes = 2840 , elements = 12780

[b]. Average temperature = 30.26[c].

[c] no of ietarions = 150.

case_2:- for momentum ratio =4

gemoetry section:-

meshing:-

setup:-

SET UP :-

1. K-EPSILON

2. SOLVER - PRESSURE BASED

3. VELOCITY FORMULATION - ABSOLUTE.

4. Time- steady state

5. viscous model - k-epsilon

6. cell zones - AIR

7. boundary conditions:- velocity maginitude = 3,3 [for both cases].x - inlet.

velocity magnitude = 12 y- inlet

8. tem = 36,19 [for both cases].

solution reports:-

TEMPERATURE AND VELOCITY PLOTS:-

[A]. CELL COUNT = 2840, E-127890

[B]. AVERAGE TEMPERATURE = 27.5.

[C]. NO OF ITERATIONS = 140

FOR LONG TEE M =2:-

SET UP:-

FOR M= 4:-

FOR m =2 , average temperature = 30, iterations = 170

for m =4 , average temerature = 27.4. iterations = 130

Conclusion:-

1. the length of the pipe increases the mixing has a lot of time and increases the temperature losing its main objective.

2. meshng has improved for both cases.

3. k-epsilon and k-omega are give better results for both cases