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ANSYS Maxwell 3D Field Simulator v16 User’s Guide
12.4 Prius Motor - Maxwell 2D Transient to FLUENT 3D Steady State
2-Way Coupling with Demagnetization
12.4-‹#›
Maxwell v16
Maxwell 2D Transient to FLUENT 3D Steady State 2-Way Coupling with Demagnetization
This workshop shows how Maxwell 2D transient is 2-way coupled with FLUENT 3d steady state. Time averaged but spatially distributive Ohmic losses in the magnets and core losses in the stator and rotor are transferred from Maxwell 2D to a 3D mesh in FLUENT for temperature calculation. Then temperature is mapped back to Maxwell to affect electrical conductivity and B-H curves. Demagnetization is also turned on in Maxwell. This workshop shows steps related to transferring losses from Maxwell to FLUENT and does not contain details about Maxwell or FLUENT. Please refer to FLUENT Users’ Guide for information on FLUENT Setup
Prerequisites
Maxwell V16 and FLUENT V14.5 need to be installed in order to carry out this workshop, which are releases under ANSYS Workbench R14.5. ANSYS Workbench needs to be installed for the loss transfer.
Geometry and mesh used inside FLUENT
ANSYS Maxwell 3D Field Simulator v16 User’s Guide
12.4 Prius Motor - Maxwell 2D Transient to FLUENT 3D Steady State
2-Way Coupling with Demagnetization
12.4-‹#›
Maxwell v16
The Maxwell Project The Maxwell project contains a 2D geometry of a Prius motor The setup of this motor has already been partially done To obtain more details about the setup please refer to Example 11.1 of Maxwell 2D Workshops
Stator
Phase A
Phase B
Phase C
Magnets
Rotor
Shaft
ANSYS Maxwell 3D Field Simulator v16 User’s Guide
12.4 Prius Motor - Maxwell 2D Transient to FLUENT 3D Steady State
2-Way Coupling with Demagnetization
12.4-‹#›
Maxwell v16
Launch Maxwell To Lunch Maxwell
Double the Maxwell icon Or go to All Programs and look for your Ansoft installation.
Change Material for the Magnets
RMB on NdFe35 and select Properties.. Select Add Material Make the changes according to the panel
Name Nonlinear 625000 Thermal Modifier 1.0-0.0010876*(Temp-20) 1.0-0.00647425*(Temp-20)
ANSYS Maxwell 3D Field Simulator v16 User’s Guide
12.4 Prius Motor - Maxwell 2D Transient to FLUENT 3D Steady State
2-Way Coupling with Demagnetization
12.4-‹#›
Maxwell v16
Import Intrinsic B-H Curve Click B-H Curve
Select Intrinsic and answer no to the pop-up question. Select Import Dataset and select the provided B-H curve file, intrinsic_BH.tab. This is the intrinsic B-H curve at the reference temperature of 20 C.
ANSYS Maxwell 3D Field Simulator v16 User’s Guide
12.4 Prius Motor - Maxwell 2D Transient to FLUENT 3D Steady State
2-Way Coupling with Demagnetization
12.4-‹#›
Maxwell v16
Make Copper Conductivity a Function of Temperature RMB on Copper and select Properties.. Select View/Edit Material Make the changes according to the panel
Thermal Modifier 1.0/(1.0+0.0068*(Temp-20))
ANSYS Maxwell 3D Field Simulator v16 User’s Guide
12.4 Prius Motor - Maxwell 2D Transient to FLUENT 3D Steady State
2-Way Coupling with Demagnetization
12.4-‹#›
Maxwell v16
Set up Temperature Dependency Go to Maxwell 2D>Set Object Temperature Make the changes according to the panel
Set up Demagnitization (Optional)
Go to Setup1
20 C is the reference
temperature
ANSYS Maxwell 3D Field Simulator v16 User’s Guide
12.4 Prius Motor - Maxwell 2D Transient to FLUENT 3D Steady State
2-Way Coupling with Demagnetization
12.4-‹#›
Maxwell v16
Simulate and Plot Torque Go to Analysis and do the simulation. Plot Torque vs Time
Note that you could redo the calculation with a different temperature. Below is the new torque results with temperature of 100 C. The torque is reduced with elevated temperature. Save and Close Maxwell.
This concludes the Maxwell standalone calculation.
ANSYS Maxwell 3D Field Simulator v16 User’s Guide
12.4 Prius Motor - Maxwell 2D Transient to FLUENT 3D Steady State
2-Way Coupling with Demagnetization
12.4-‹#›
Maxwell v16
Coupled Simulation with Fluent Will Be Performed Next Launch ANSYS Workbench
To Launch Workbench Select the Microsoft Start button , select All Programs > ANSYS 14.5> Workbench 14.5
Import Maxwell Project File Since we are using an existing Maxwell project, we will import it into Workbench. Users can create a new Maxwell Analysis System to setup a new problem. To Import Maxwell File
Select the menu item File > Import Change the file type to Maxwell Project File (*.mxwl) Browse to the location where workshop input files are located Select the file “Ex_12_4_2Way_Demag.mxwl” and Open it.
Launch Maxwell
A Maxwell analysis system will be created as shown below. To Lunch Maxwell
Double click on the solution tab of Maxwell analysis system.
ANSYS Maxwell 3D Field Simulator v16 User’s Guide
12.4 Prius Motor - Maxwell 2D Transient to FLUENT 3D Steady State
2-Way Coupling with Demagnetization
12.4-‹#›
Maxwell v16
Set up Feedback Go to Maxwell2D > Set up Object Temperature Enable feedback
Analyze
To start the solution process Select the menu item Maxwell 2D > Analyze All This may take up to 5 min.
ANSYS Maxwell 3D Field Simulator v16 User’s Guide
12.4 Prius Motor - Maxwell 2D Transient to FLUENT 3D Steady State
2-Way Coupling with Demagnetization
12.4-‹#›
Maxwell v16
Plot Losses Create Parameter for Total Losses
Select the menu item Maxwell 2D > Fields > Calculator 1. Select Input > Quantity >TotalLoss 2. Select Input >Geometry >Surface > Stator 3. Select Scalar > integrate 4. Select Add 5. Specify the name of the expression as Loss_Stator 6. Press Done
Plot Loss Vs Time Select the menu item Maxwell 2D > Results > Create Field Reports > Rectangular Plot In Report window
1. Category: Calculator Expressions 2. Quantity: Loss_Stator 3. Select New Report 4. Press Close 5. Choose the range as shown to plot the results.
ANSYS Maxwell 3D Field Simulator v16 User’s Guide
12.4 Prius Motor - Maxwell 2D Transient to FLUENT 3D Steady State
2-Way Coupling with Demagnetization
12.4-‹#›
Maxwell v16
Calculate Time Average Losses Right click on the plot and select the option Trace Characteristics > Add In Add Trace Characteristics window,
1. Category: Math 2. Function: avg 3. Range: Specified 4. Select Add and Done
The value displayed is around 1206.9 watts It shows time averaged Total Losses for the stator Since this is a 2D case, these losses are in watts per meter We need to multiply this value with length of stator in order to calculate true losses. Since the length is 0.08382 m, the actual total loss for the stator is : 101.2 watts (The correct answer should be 50.6 watts. The bug has been fixed in V17.)
ANSYS Maxwell 3D Field Simulator v16 User’s Guide
12.4 Prius Motor - Maxwell 2D Transient to FLUENT 3D Steady State
2-Way Coupling with Demagnetization
12.4-‹#›
Maxwell v16
Close Maxwell To Close Maxwell window
Select the menu item File > Close Desktop
Turn on Beta Option
Go to Tools > Options > Appearances to turn on beta option. Beta option is needed for two-way transient Maxwell steady state Fluent coupling.
Save
To Save Workbench Project Return to Workbench Project window Select the menu item File > Save Save the file with the name “Ex_12_4_2Way_Demag.wbpj
ANSYS Maxwell 3D Field Simulator v16 User’s Guide
12.4 Prius Motor - Maxwell 2D Transient to FLUENT 3D Steady State
2-Way Coupling with Demagnetization
12.4-‹#›
Maxwell v16
Create a FLUENT Component System To Create a FLUENT Component System
Expand the Toolbox for Component Systems and select a Fluent component system from it. Drag and drop the FLUENT System on Project page
Load FLUENT Case File A CFD case file has been provided with the workshop. The case file has all proper setup. This workshop will demonstrate the loss mapping process. To Load Case File
Right click on Setup tab of FLUENT Analysis system and select Import FLUENT Case > Browse Browse to the correct location and select the FLUENT case file “Ex_12_4_2Way_Demag.cas.gz” and select Open A FLUENT Launcher window will pop up as shown in below image. Select Double Precision and press OK to it. A FLUENT window will launch and case file will be imported into FLUENT
ANSYS Maxwell 3D Field Simulator v16 User’s Guide
12.4 Prius Motor - Maxwell 2D Transient to FLUENT 3D Steady State
2-Way Coupling with Demagnetization
12.4-‹#›
Maxwell v16
Build Links To Create Links
Without closing FLUENT window, return to Workbench project page Drag and drop Solution tab of Maxwell Analysis system onto the Setup tab of FLUENT system Right click on Solution tab of Maxwell Analysis system and select Update Press OK to the pop up window.
Initialize Solution To Initialize the Solution
Go to Solution > Solution Initialization Change the Initialization type to Standard Initialization Press Initialize Note: It is not necessary to initialize the solution before mapping the losses from Maxwell. If you initialize the solution after mapping losses, mapping will be redone automatically
ANSYS Maxwell 3D Field Simulator v16 User’s Guide
12.4 Prius Motor - Maxwell 2D Transient to FLUENT 3D Steady State
2-Way Coupling with Demagnetization
12.4-‹#›
Maxwell v16
Map Losses from Maxwell To Maps Losses from Maxwell
Select the menu item File > EM Mapping > Volumetric Energy Source In Maxwell Mapping window,
FLUENT Cell Zones: Press Ctrl and select the four zones solid-magnet, solid-rotor, solid-teeth, and solid-yoke. Start: 2.083e-4 Stop: 1.667e-3 Press OK
Mapped Losses After data mapping, FLUENT will display the loss values mapped to selected zones The losses reported for the stator (zone 31 and 37) is 50.1watts Remember that total losses for the stator calculated from Maxwell was 50.6 watts. It can be verified that losses for other regions are also correct.
ANSYS Maxwell 3D Field Simulator v16 User’s Guide
12.4 Prius Motor - Maxwell 2D Transient to FLUENT 3D Steady State
2-Way Coupling with Demagnetization
12.4-‹#›
Maxwell v16
Perform the Simulation Simulate for 20 iterations using all setting in the case file
Plot Temperature Distribution
To Plot Temperature Go to Display > Graphics and Animations… and double click Contours In Contours window,
Filled: Checked Contour of: Temperature > Static Temperature Surfaces: select all periodic and solid (Tip: using the Match) Press Display and Close
Note: The windings have the highest temperature as expected. There is a temperature gradient across the air gap. The thermal conductivity for the air gap is increased to model the enhanced heat transfer at the gap due to motion.
ANSYS Maxwell 3D Field Simulator v16 User’s Guide
12.4 Prius Motor - Maxwell 2D Transient to FLUENT 3D Steady State
2-Way Coupling with Demagnetization
12.4-‹#›
Maxwell v16
Perform Temperature Feedback and 2-Way Coupling Go back to Workbench schematic RMB Solution of Maxwell2D and Enable Update Double click Solution to launch Maxwell Reset time to zero and redo the analysis
RMB Setup1 to reset time to zero. The torque is much less due to magnet being function of temperature. Display temperature to show temperature distribution on the magnets.
ANSYS Maxwell 3D Field Simulator v16 User’s Guide
12.4 Prius Motor - Maxwell 2D Transient to FLUENT 3D Steady State
2-Way Coupling with Demagnetization
12.4-‹#›
Maxwell v16
Perform Fluent Analysis again Following the Same Procedure The new mapped loss is the following.
After Some Coupling Iterations, Temperature Converges to a Level Acceptable. Below is a Plot of Temperature Convergence History.