1. Mechanical Engineering 4J03
McMaster University
Project #2
Prepared For: Dr. Hamed
Date of Tutorial: March 6, 2015
Assignment Due Date: March 20, 2015
Prepared By: Shaun Chiasson, 1070043

2. Objective:
A cooling tank was to be examined for flow characteristics and pressure drop in order to
determine a means to stabilize the water velocity that passes the cooling chamber. A design
needed to be created that could bring the velocity at the chamber to a steady value within
specified values while having an unlimited pressure allowance. The final design was to include
the use of baffles and not change the tank in anyway.
Results:
From the given information in the problem the inlet velocity calculated was 0.673 m/s.
The initial grid size indicated was too small to work with so a grid ten times larger was used.
The original grid called for a 0.0007m mesh but instead a 0.007m mesh was used instead in order
to save computation time.
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Figure 1: Flow velocity vector plot for the case of no baffles installed.

3. Figure 2: Graph of velocity magnitudes for inspection lines A, B, and C for the case of no baffles installed.
Figure 3: Graph of pressure magnitudes for inspection lines A, and C for the case of no baffles installed.

4. Figure 4: First two attempts at a suitable baffle design.
Figure 5: Second set of two attempts at a suitable baffle design.

5. Figure 6: Third set of two attempts at a suitable baffle design.
Figure 6: Fourth set of two attempts at a suitable baffle design.

6. Figure 7: Fifth set of two attempts at a suitable baffle design.
Figure 8: Final baffle design velocity vector plot.

7. It is important to note that none of the designs tested would converge to the prescribed
1.0E-5 residual within the recommended three hundred iterations. Some designs did converge to
the standard residual of 1.0E-4 but did not meet the requirements of the project. There was also
sinusoidal variance in the residuals but not sufficient time to use double precision. Since none of
the solutions are sufficient to meet the requirements and convergence was not met a grid
independence test was not necessary. The final design presented here could meet the criteria
with more work on the proposed geometry and may converge to 1.0E-5 if more iterations were
allowed to run. The solution presented here has been resolved sufficiently well to conclude that
the design can be reworked into a successful configuration because the mesh had been refined in
the areas of the baffles where the gradients are highest as shown in Figure 9.
Figure 9: Final baffle design mesh used in the solver.

8. Figure 10: Graph of velocity magnitude for inspection line B for the final design.
Figure 11: Graph of pressure magnitudes for inspection lines A, and C for the final design.

9. Figure 12: Dimensions for the geometry of the final baffle design configuration.
Note: Only the minimum amounts of dimensions are shown and those not shown can be assumed to be the same as
others that are of the same magnitude and shown in the figure above.
Discussion:
The criterion for the velocity of the water states that an average of 80 fpm with a range of
plus or minus ten percent would be desirable. To interpret the graphs above these values needed
to be converted to meters per second.
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Figure 10 illustrates that a portion of the velocity magnitude graph lies within the range
specified. This portion of the graph is fairly close to the edge of the cooling chamber circle, and
this is the main reason to believe that with some minor alterations the final design could be made

10. to satisfy the design criteria. The average velocity over the whole inspection line B will now be
calculated from the graphs and compared to that of the case with no baffles installed.
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The addition of the baffle system has had a big impact on the average velocity of the
water passing by inspection line B. This is the desired effect since the water initially enters the
tank at a velocity of 0.673 m/s it is necessary to try and slow it down a great deal in order to
attempt to reach the target velocity of 0.41 m/s. The addition of the baffles comes at a price
however; the pressure drop in the tank has increased and will now be examined.
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The calculations above indicate that for relatively small decreases in the average velocity
of the water a very large pressure drop will be required. This could mean that if more baffles are
inserted in an appropriate arrangement to distribute the flow, then the target average velocity
may be attained. The pressure drop found in the simulation is not difficult to achieve when
pumping a fluid such as water because it is fairly easy to pump liquids to high pressures.
Conclusion:
The final design is less than ideal but has the potential to lead to a much better solution to
the given design problem with some geometric modifications. The addition of more baffles will
result in a greater pressure drop but that should not be a problem because of how easy it is to
pump liquids to high pressures. In this case it may be a better idea to redesign the entire tank to
attain an even velocity profile along inspection line B.