Tutorial 3 Comfort index in a room

This tutorial is similar to tutorial 2, but with an added person sitting on a chair as shown in the following figure. The case is to show how to activate the comfort index calculation.

Setting up the model

Follow the step-by-step instructions for Tutorial 2 in section 6.2.1, from 1. Start FLAIR with the default room to 3. Adding objects to the room; j. add the adiabatic walls at the x plane (west). Then we add a sitting person and a chair as follows.

  1. Start FLAIR with the default room

    The same as for tutorial 2

  2. Resize the room

    The same as for tutorial 2

  3. Adding objects to the room

a. b. c. d. e. f. g. h. i. j sections are the same as for tutorial 2

k. add a chair

X: 0.46 m

Y: 0.39 m

Z: 1.0 m

X: 0.75 m

Y: 0.6 m

Z: 0.0 m

l. add a sitting person

The PERSON object is used to set the heat source. Its material is the domain material (air in this case).

X: 0.88 m

Y: 0.74 m

Z: 0.0 m

To activate the physical models

a. The Main Menu panel

FLAIR always solves pressure and velocities. The temperature is also solved as the default setting.

The 'Models' page of the Main Menu.

b. To activate LVEL turbulence model

c. To activate IMMERSOL radiation model

  d. To activate Comfort indices

To set the grid numbers and to solver parameters

in X-direction to 20 cells

in Y-direction to 40 cells

in Z-direction to 22 cells

with the following sub-region's modifications:


Cell Number

  X Y Z
1 1 5 7
2 4 2 1
3 1 2 6
4 2 2 1
5 1 1 1
6 4 8 2
7 3 5 2
8 2 7 2
9 2 8 (n/a)

Note that there are only 8 regions in Z-direction.

You can click on the mesh toggle button, on the main control panel to view the grid distribution on the screen as shown below.

Variable W1 TEM1

FIINIT Value 0.01 20

The above initial settings are used to secure the convergence.

Variables T3 TEM1

VARMIN 15 15

The above settings are used to secure the convergence.

Running the Solver

To run the PHOENICS solver, Earth, click on 'Run', then 'Solver', then click on 'OK' to confirm running Earth. These actions should result in the PHOENICS Earth monitoring screen.

As the Earth solver starts and the flow calculations commence, two graphs should appear on the screen. The left-hand graph shows the variation of solved variables at the monitoring point that was set during the model definition. The right-hand graph shows the variation of errors as the solution progresses.

To the end of the calculation, the monitoring display would be as shown below.

Viewing the results

Velocity vectors at X= 0.1m plane

The value of predicted PMV is between +1(slightly warm) and -1(slightly cool).

Saving the case

Once a case has been completed, it can be saved to disk as a new Q1 file by 'File - Save working files'. The Q1 and associated output files can be saved more permanently by 'File - Save as a case'.