Learning Forum

[ananyas]

Hello,

I am using Ansys 2019R1 w/ academic license. I am new to Fluent.I have the following simple experiment model and queries:

Experiment model:

A cylindrical enclosure of incompressible carbon monoxide w/ a heater placed in between. The bottom and top face are the pressure inlet (10mPa) and outlet (0mPa) as shown in the figure of the contour plots below. I run a simple transient simulation with 10 iterations.

Queries:

I have following queries with the units and result graphs.

1. I create a new unit i.e. mPa and use 10mPa pressure as the input as show below:

However when I see the contour plot of the total pressure, the value of pressure are extremely high and doesn't make any sense.

also, input and output pressure seems to be equal. How is it so?

2. I tried giving a sinusoidal pressure pulse as the input using the following UDF

However, when I see the vector plot of the pressure, the pressure seems to be constant rather than sinusoidal in nature w/ extremely high values. How is it so?

Also, following is the pressure plot w.r.t. time, which doesn't make any sense either

 

Kindly help with the above two queries.

Best,

Ananya

 

 

[DrAmine]

1/MPa is Mega Pascal right? Then your factor is wrong

2/When working with UDF please use S.I units (Pascal for pressure)

[ananyas]

Hello Amine,

1. mPa is milli-Pascal.

The issue is I don't see any pressure variation for the inlet (10 mPa) or outlet (0 mPa) in either contour plots or pressure plots w.r.t. time.

2. I am using Pa as the unit and so I use an amplitude of 0.005 to represent 5mPa.

here again, I don't see any sinusoidal behavior when I plot the pressure w.r.t. time.

Best,
Ananya