Homework Assignment

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Revision as of 18:23, 5 May 2019 by Marcsa (talk | contribs) (Calculating the force on the solenoid valve by finite element method)

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Analysis of Solenoid Valve

Instructor

  • Dániel Marcsa (lecturer)
  • Lectures: Monday, 14:50 - 16:25 (D201), 16:30 - 17:15 (D105)
  • Office hours: by request

Teaching Assistants:

  • -
  • Office hours: -.

Aim of Assignment

Students will learn the basics of electromagnetic field calculations, their main steps, and gain practice in evaluating results and writing a Technical Report that meets international expectations.

Knowledge needed to solve the problem

  • The main steps of the finite element method;
  • Theoretical knowledge of the static magnetic field (for defining materials, for excitation);
  • Knowledge of CAD system to create geometry;
  • Download and install ANSYS AIM Student.

The Semester Assignment

The task consists of two parts, a basic task, with a faultless solution of up to 70%, and an extra task, with an additional maximum of 30%.

Deadline May 25, 2019, 12:00
Output Form: PDF format. Color drawings should be made so that their contents are clear to the reader in black and white.
Language English
Place of submission: marcsa@maxwell.sze.hu email address
Late submission: After every day started, a 5% deduction from the achieved result (i.e. after 5 days delay 100% can only be obtained up to 100% - 5x5% = 75%).
Evaluation: 0 - 48% - Insufficient [F] (1)
50 - 59% - Sufficient [D] (2)
60 - 70% Satisfactory [C] (3)
71 - 84% Good [B] (4)
85 - 100% - Very good [A] (5)
For the formal requirements, the requirements of CFD and mechanics are also valid here.

Part I of the Assignment

Calculating the force on the solenoid valve by finite element method

The geometry and dimensions of the task.

The task is cylindrical to the vertical ([math]z[/math]) axis, and the three-dimensional geometry must be prepared according to the specified dimensions (see figure).

Tasks

  • Define the problem type based on the given parameters;
  • Creating and specifying the task geometry in ANSYS Discovery AIM;
  • Run the FEM simulation;
  • Validation of results for a 2mm air gap.

|+ The results of the simulations. ! Software ! Discovery AIM ! Maxwell 3D ! FEMM ! Maxwell 2D |- ! Force [N] | 3,586 || 3,582 || 3,542 || 3,587 |- ! Inductance [mH] | 39,88 | 39,84 | 39,71 | 39,84 |}

  • Test of Solution Performance (Solution performance tuning, Curved surface meshing) as a function of force;
  • Number of finite elements (Tetrahedra), Energy (Total Energy), Energy Error and Delta Energy in the function of adaptive steps in two different cases;
  • Postprocessing [at least two of the below]:
1) determination of force and inductance;
2) displaying equipotential lines;
3) display the minimum and maximum of the magnetic flux density;
4) display the magnetic field strength;
5) displaying magnetic flux density vectors.
  • Preparation of a Technical Report based on the use of the above results.

Note: The “Part I of the Assignment” elements will be reviewed in detail during the exercise to prepare and run a simulation model for an electromagnetic task. On this basis, students can easily complete Part I of the Assignment by attending the exercises.

Parameters for this Assignment:
Relative permeability of air and coil [math]\mu_r = 1[/math];
The excitation of the coil (To validate the results): [math]I=0.76~\text{A}[/math], [math]N=789~\text{turns}[/math] (DC);
Magnetic curve of the core and plunge:

BHCurve Steel1008.PNG

Figure 1. - Steel 1008 steel magnetization curve.

Part II of the Assignment

Determining the force acting on the moving part of the problem (plunger) and the inductance of the coil as a function of displacement.

Note: This task corresponds to the solenoid valve in internal combustion engines that controls the injection.

Specific tasks
  • Considering the plunger movement to the initial state (2mm air gap) from [math]-1.8\text{mm} \text{ to } 10\text{mm}[/math] (at least in 7 positions). Detailed instructions on the solution will not be available.
  • This part is intended to measure the degree of autonomy, initiative and diligence of the student, i.e.:
    1. is the student able to do independent work;
    2. to design, assemble and run the simulation alone.

References