Turbo Ventilator, ANSYS Fluent CFD Simulation Tutorial

Description

Introduction

This project is related to a simulation of an Air Turbo Ventilator using ANSYS Fluent software. We perform this CFD project and investigate it by CFD analysis.

This system is included in the category of passive ventilation methods. In passive ventilation systems, no active mechanical device is involved.

Generally, passive ventilation systems are included in two groups, which are wind-driven and buoyancy-driven.

The air turbo ventilator is one type of wind-driven passive ventilation group. This means that only the pressure difference causes air circulation.

A turbo air ventilator uses air energy to move out the airflow. An air turbo ventilator consists of a rotating turbine installed on the roof of buildings.

The warm air is light and less dense and goes to the top of the space. The contact of the air with the ventilator blades causes a rotational movement. On the other hand, the free wind flow on the buildings’ roofs strengthens the blades’ rotation speed.

So, the pressure difference between the inside and outside of the building is created, and the ventilator causes air suction.

This system has many advantages. They can work continuously 24 hours a day while consuming no energy. In addition, these systems can air conditioning by removing dust and pollutants.

We designed the geometry of the model using Design Modeler software. The computational zone of the model is related to the room’s interior space. Two air turbo ventilators are installed on the ceiling of this room.

Then we meshed the model using ANSYS Meshing software. The meshing is unstructured, and the number of created cells equals 2094625.

Turbo Ventilator Methodology

Using ANSYS Fluent software, we numerically simulated this model according to computational fluid dynamics (CFD). This problem is independent of time and steady state, and the solution is based on the pressure-based solver.

As we said, natural convection heat transfer also happens in this problem. Natural convection is created based on the buoyancy effect. This means that changes in temperature cause changes in density. Warm air is lighter and less dense and rises upwards.

Therefore, the current system is useful for the exit of hot air. The entry of cool air from the floor of the room and the air suction from the exit panel of the tower helps the exit of hot air.

In this problem, we must define the rotation movement of two ventilators. We use the multiple reference frame (MRF) methods.

We create two distinct zones adjacent to the turbine blades within the total computational domain. Now we define the rotational movement for these zones.

Since the airflow direction is parallel to the central axis of the ventilators, we use the frame motion method. We have set the rotational velocity equal to 100 rad/s.

Turbo Ventilator Conclusion

After the simulation, we obtained 2D and 3D pressure and velocity contours. We also obtained 2D and 3D velocity vectors.

The pressure contour correctly shows the pressure difference. So the pressure difference causes air suction.

On the other hand, the velocity vectors around the ventilator blades show the rotational movement of the airflow. These velocity vectors in the vicinity of the ventilators show that air suction from inside the room occurs through the ventilators.

So, we conclude that this air turbo ventilator system performs the air conditioning process correctly.