Design of an Axial Fan Using Ansys TurboSystem - CFD Setup
Welcome to part 4 of our demonstration on the design and analysis of an axial fan. In this session, we will delve into one of my favorite subjects: Computational Fluid Dynamics (CFD). ANSYS provides robust CFD tools such as Fluent and CFX. Today, we will focus on CFX, which offers unique capabilities for turbomachinery flow simulation.
Data Transfer and Setup in CFX
We will begin by transferring our mesh data, generated in the previous step using TurboGrid, to CFX. Follow these steps:
- Transfer data to CFX.
- Click the Setup button to launch CFX Pre.
CFX comprises three modules: Pre, Solver, and CFD Post. We will focus on using CFX Pre for turbomachinery applications.
Setting Up the CFD Model
Within CFX Pre, you can see the mesh outline. The next steps involve assigning flow physics and boundary conditions to set up the CFD model:
- Normally, users select each surface to assign boundary conditions. However, CFX offers a special tool that simplifies this process when you switch to Turbo Mode.
- For our fan, the coordinate frame wraps around the Z-axis, and we are solving a steady-state problem.
Defining the Problem
Using the wizard in Turbo Mode, we define our problem as follows:
- Component: Block for R1
- Rotating Speed: 3000 RPM
Next, we set the physics boundary conditions:
- Air Temperature: 25°C
- Pressure: Atmospheric
- Total Mass and Pressure at the Inlet
- Mass Flow Rate per Passage: 0.069 kg/s (calculated as 2 divided by 29 passages)
Interfaces and Boundary Conditions
The interfaces are automatically captured, simplifying the process. The boundary conditions are also predefined:
- Inlet: Total Pressure
- Outlet: Mass Flow Rate
The setup is efficiently completed using the Turbo Tool in CFX.
Solving the CFD Model
Once the setup is complete in CFX Pre, minimize the window and proceed to the solution:
- Double-click on Solution to start the CFX Solver.
The solver opens a new window to track the progress of iterations. Once the flow solution converges, we will review the results in the next session.
Design of an Axial Fan using Ansys TurboSystem - CFD Setup Hello, welcome to part 4 of our demonstration on the design and analysis of an axial fan. We've reached my favorite subject: computational fluid dynamics.
ANSYS offers strong CFD tools, such as Fluent and CFX, and I'll particularly talk about CFX, which has unique capabilities for turbo machinery flow simulation. We'll transfer data to new and select CFX, which will transfer our mesh generated in TurboGrid.
We'll hit the setup button, bringing up CFX Pre. CFX has three different modules: the pre-solver and a CFD post component. We'll see how to use CFX Pre, specifically for turbo machinery type applications. As you can see, we can view the outline of the mesh.
We'll assign flow physics boundary conditions to set up the CFD model. CFX has a special tool that makes life easy when defining specific turbo machinery problems. We'll work on a fan, with our coordinate frame wrapping around the Z-axis, in a steady-state solution.
Components include a block for R1, with a rotating speed of 3000 RPM. We'll send air at 25 degrees Celsius and atmospheric pressure, using a total pressure at the inlet and a mass flow rate per passage (2/29 passages, approximately 0.069 kilograms per second).
Interfaces are automatically captured, and boundary conditions are readily defined. At the inlet, we specified total pressure, and at the outlet, we specify the mass flow rate.
Once the setup is complete in CFX Pre, we'll start the CFX solver, track the progress of iterations, and examine the results in the next session.
