## Ansys Free Student Software

#### Simulating a fish raceway in ANSYS

• Eman Mohie El-Din
Subscriber

Hello there,

I hope you're doing well. Please bear with me as I explain the following image, which shows an aquaculture called "IPRS" or "In Pond Raceway System". This system includes a large pond with three raceways, each occupying about 2-3% of the total pond area. The raceways are equipped with gates at the inlets and outlets to prevent fish from escaping into the pond, and an aerator at the beginning of each raceway.

Now, on to my questions. I'm a beginner, and I'd like to simulate an individual raceway with the gates, aerator, and fish waste. Currently, I've only simulated the raceway as a rectangular shape with four surfaces (including inlet and outlet surfaces), and I've assigned an air mass flux and water mass flow for the inlet.

My goals are to simulate the water in the raceway in a steady state (including setting a water level if possible), create an area for the air (i.e., if the water depth is 1.5 meters and the total depth is 2 meters, the remaining 0.5 meters should be filled with air) *Problem 1*, simulate the aerator itself in the raceway *Problem 2*, and simulate the fish waste *Problem 3*.

What's the best way for me to accomplish all of these goals or learn how to do so efficiently?

• Nikhil Narale
Ansys Employee

Hello,

"My goals are to simulate the water in the raceway in a steady state (including setting a water level if possible), create an area for the air (i.e., if the water depth is 1.5 meters and the total depth is 2 meters, the remaining 0.5 meters should be filled with air) "

You may have to perform a multiphase VOF simulation, which will track the interface between water and air. Look out for some tutorials.

"simulate the aerator itself in the raceway"

What is the objective for this? If you know the flow parameters after aerator, you can directly give it as the inlet boundary conditions (inlet of the raceway).

"simulate the fish waste"

If you want to simulate the effect of water flow on the fish waste, then you may also want to explore Discrete Phase Modeling (DPM).

It is a good practice to do some simplifications and careful consideration/assumptions of the relevant physics to fit in the framework and capabilities of the simulation.

Thank you!

• Eman Mohie El-Din
Subscriber

We've already carried out a multiphase simulation to model the air bubbles, and we have also simulated the fish waste. It is essential to include the aerator in the simulation as it enables us to observe how the resulting air bubbles are distributed depending on where the aerator is located.

Do you have any ideas/hints on how to simulate it?

We also think of simulating the gates but the porous media thing seems to not achieve what we need

Best Regards.