Drawing a Complex Shape (COMSOL) Introduction We wish to draw the region depicted in Fig. 14.21, which is needed in Example 11.3 for solving non-Newtonian flow in an extrusion die. Briefly, we shall draw two overlapping rectangles and cut out or subtract from them two other regions known as “Bézier

Question

Drawing a Complex Shape (COMSOL)

Introduction

We wish to draw the region depicted in Fig. 14.21, which is needed in Example [latex]11.3[/latex] for solving non-Newtonian flow in an extrusion die. Briefly, we shall draw two overlapping rectangles and cut out or subtract from them two other regions known as "Bézier polygons."

Accepted Answer

Procedure

All mouse clicks are left-click ("Select"), unless specifically denoted as R-Click.

Select the Physics

Open COMSOL and L-click Model Wizard, 2D Axisymmetric, Fluid Flow (the little rotating triangle is called a "glyph"), Single-Phase Flow, Laminar Flow. L-click Add, Study, Stationary, Done.

Select Spacings on the [latex]r[/latex] and z Axes

Expand Component 1 to View 1 and L-click Axis. Select Manual spacing and set the [latex]r[/latex] and [latex]z[/latex] spacings to [latex]0.003[/latex], with all dimensions being in meters [latex](\mathrm{m})[/latex]. L-click Update.

Draw Rectangles

Our first goal is to draw the two rectangles, [latex]\mathrm{r} 1[/latex] and [latex]\mathrm{r} 2[/latex], as shown in Fig. 14.22(a). For the first of these, r1, R-click Geometry and select Rectangle. Enter the values for Width and Height as [latex]0.009[/latex] and [latex]0.021[/latex] (always units of [latex]\mathrm{m}[/latex] ). Note the default is based on the lower-left corner located at [latex](0,0)[/latex]. Build Selected.
For the second rectangle, r2, R-click Geometry and select Rectangle. Enter the values for Width and Height as [latex]0.012[/latex] and [latex]0.027[/latex]. Update the corner position to [latex](0.006,-0.021)[/latex]. L-click Build Selected. L-click the Zoom Extents button at the top of the Graphics window, giving Fig.14.22(a), showing both [latex]\mathrm{r} 1[/latex] and [latex]\mathrm{r} 2[/latex].

Draw Bézier Polygons

Our second goal is to draw the two Bézier polygons, b1 and b2, shown in Figs. 14.22(b) and (c). R-click Geometry and select Bézier Polygon. L-click Add Quadratic. Enter the following three control points, 1-2-3: [latex](0,0.003),(0.012,[/latex], [latex]0.003)[/latex], and [latex](0.012,-0.009)[/latex]. L-click Add Quadratic. Enter the following three control points, 3-4-5: [latex](0.012,-0.009),(0.006,-0.009)[/latex], and [latex](0.006,-0.015)[/latex]. Leftclick Add Linear. Enter the following two control points, 5-6: [latex](0.006,-0.015)[/latex] and [latex](0,-0.015)[/latex]. L-click Add Linear and immediately L-click Close Curve. Build Selected, giving the polygon b1 in Fig14.22(b).
R-click Geometry and select Bézier Polygon. L-click Add Quadratic. Enter the following three control points, 7-8-9: [latex](0.009,0.006),(0.009,0.003)[/latex], and [latex](0.012,[/latex], [latex]0.003)[/latex]. L-click Add Quadratic. Enter the following three control points, [latex]9-10-11:[/latex] [latex](0.012,0.003),(0.018,0.003)[/latex], and [latex](0.018,-0.003)[/latex]. L-click Add Linear. Enter the following two control points, 11-12: [latex](0.018,-0.003)[/latex] and [latex](0.018,0.006) .[/latex] L-click Add Linear and immediately L-click Close Curve. Build Selected, giving the polygon b2 in Fig14.22(c).

Subtract Polygons from Rectangles

R-click Geometry, Boolean and Partitions, Difference. L-click the On/Off toggle for Objects to add in the Settings window. Hover and successively L-click rectangles r1 and r2. L-click the On/Off toggle for Objects to subtract in the Settings window. Hover and successively L-click the Bézier Polygons b1 and b2. Because we want one unified object, deselect the Keep interior boundaries option.
L-click Build All Objects, finally giving Fig. 14.22(d).
Save the completed shape for the die in the file Ex14.2-9.mph, which is used in Example 11.3.

Question 14.2: Drawing a Complex Shape (COMSOL) Introduction We wish to dra...

This Question has been Answered.

Already have an account?

Login

Related Answered Questions