Tutorial 2: Parametric Analysis in ANSYS Workbench Using ANSYS Fluent

Problem Description

As we all know that evaluation of vehicle air conditioning systems was performed using prototypes and testing their performance in test labs. Whereas, the introduction of Computer Aided Design (CAD) has been improved with the the design process of modern vehicle air conditioning (AC) systems , Computer Aided Engineering (CAE) and Computer Aided Manufacturing (CAM).

CFD enables the analysis of fluid through very complex geometry and boundary conditions.

Adding Constraints to ANSYS DesignModeler Parameters in ANSYS Workbench

In this step,  start ANSYS Workbench, open the project file, review existing parameters, create new parameters, and add constraints to existing ANSYS Design Modeler parameters.

  1. From the Windows Start menu, select

Start > All Programs > ANSYS 18.0 > Workbench 18.0 to start ANSYS Workbench.

version can be anything,it do not depends

  • Restore the archive of the starting ANSYS Workbench project to the working directory.

File Restore Archive…

a. Browse the working directory, select the project archive file fluent-workbench-param, wbpz, and click Open.

The Save As dialog box appears.

b. Browse, if necessary, to the working folder and click Save to restore the project file, fluent-work- bench-param.wbpj, and a corresponding project folder, fluent-workbench-param_files, for this tutorial.

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3. Open the Files view in ANSYS Workbench so you can view the files associated with the current project and are written during the session.

View Files

4. Review the input parameters that have already been defined in ANSYS DesignModeler.

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5. In the Outline of All Parameters view, create three new named input parameters.

6. Select the row (or any cell in the row) that corresponds to the hcpos parameter. In the Properties of Outline view, change the value of the hcpos parameter in the Expression field from 90 to the expression min(max(25,P4),90). This puts a constraint on the value of hcpos, so that the value always remains between 25° and 90°. The redefined parameter hcpos is automatically passed to ANSYS DesignModeler. Alternatively the same constraint can also be set using the expression max

7. Select the row or any cell in the row that corresponds to the ftpos parameter and create a similar expression for ftpos: min(max(20,P5),60).

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8. Create a similar expression for wsfpos: min(max(15,P6),175).

  • Click the X on the right side of the Parameters Set tab to close it and return to the Project Schematic.
  • Update the Geometry and Mesh cells.

a. Right-click the Geometry cell and select the Update option from the context menu.

b. Likewise, right-click the Mesh cell and select the Refresh option from the context menu. Once the cell is refreshed, then right-click the Mesh cell again and select the Update option from the context menu.

11. Save the project in ANSYS Workbench.

In the main menu, select File Save

Setting Up the CFD Simulation in ANSYS Fluent

In the ANSYS Workbench Project Schematic, double-click the Setup cell in the ANSYS Fluent fluid flow analysis system. You can also right-click the Setup cell to display the context menu where you can select the Edit… option.

When ANSYS Fluent is first started, Fluent Launcher is displayed, allowing you to view and/or set certain ANSYS Fluent start-up options.

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ANSYS Fluent Launcher

1. Ensure that the proper options are enabled.

a. Ensure that the Display Mesh After Reading and Workbench Color Scheme options are enabled.

b. Ensure that Serial is selected from the Processing Options list.

c. Ensure that the Double Precision option is disabled.

2. Click OK to launch ANSYS Fluent.

Setting Up Physics

  1. In the Solver group of the Setting Up Physics ribbon tab, retain the default selection of the steady pressure- based solver.

Setting Up Physics Solver

2. Set up your models for the CFD simulation using the Models group of the Setting Up Physics ribbon tab.

a. Enable heat transfer by activating the energy equation.

b. Enable the – turbulence model.

3. Define a heat source cell zone condition for the evaporator volume.

Setting Up Physics Zones Cell Zones

a. In the Cell Zone Conditions task page, under the Zone list, select fluid-evaporator and click Edit… to open the Fluid dialog box.

b. In the Fluid dialog box, enable Source Terms.

c. In the Source Terms tab, click the Edit… button next to Energy.

d. In the Energy sources dialog box, change the Number of Energy sources to 1.

e. For the new energy source, select constant from the drop-down list, and enter   787401.6 W/m based on the evaporator load (200 W) divided by the evaporator volume (0.000254 m3) that was com- puted earlier.

f. Click OK to close the Energy Source dialog box.

g. Click OK to close the Fluid dialog box.

Solving

In the steps that follow, we will set up and run the calculation using the Solving ribbon tab.

1. Set the Solution Methods.

Solving Solution Methods…

        a. From the Scheme drop-down list, select Coupled.

  • Initialize the flow field using the Initialization group of the Solving ribbon tab.

Solving Initialization

a. Retain the default selection of Hybrid Initialization.

b. Click the Initialize button.

3. Run the simulation in ANSYS Fluent from the Run Calculation group of the Solving tab.

Solving Run Calculation

a. For Number of Iterations, enter 1000.

b. Click the Calculate button.

4. Close Fluent.

File Close Fluent

5. Save the project in ANSYS Workbench.

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