Parametric Sweep

Overview

The Parametric Sweep functions acts like a Run Sweep function. Instead of setting up multiple runs, you will have the ability to setup a sweep of runs with the Parametric Sweep function. All of the jobs are sequentially dependent on the previous jobs. The Parametric Sweep function and inputs available for each recipe is listed below:

Free Flight/FlyerXL

The Free-Flight/FlyerXL recipe will allow for a Parametric Sweep of Pitch (Angle of Attack), Yaw, and Velocity. This allows for the generation of Cd vs. alpha curves using a set of simulations at varying Angle of Attack angles and constant velocity. This is especially useful for finding the stall angle.

For max dimensions of any part in your simulation, use the following recipe:

FreeFlight-v0.0.1: < 30 m

FlyerXL-v0.0.1 : >= 30 m

VTOL

The VTOL recipe will allow for a Parametric Sweep of Yaw cases.

Setting up Sweep

  • Click on Parametric Sweep on top left navigation bar.

  • Click New Parametric Sweep and then New.

  • Change the parent name to something meaningful. The sweep of runs will then be named parentName.0, parentName.1, etc when they are published. Note: Names cannot begin with numbers or special characters.

  • Enter all available run setup inputs. Input parameters for run sweep will be blocked out and entered in a table below.

  • You can refer to the previous page for setup information:

  • Select all the required Geometry.

  • Enter Additional Geometry Information

  • Click Save.


Once you have Saved the initial settings as described above you can enter the sweep parameters.

  • Double click (or select and hit F2) the first column in the table and enter the available parametric sweep inputs. The 'Run' and 'Submitted' columns will auto populate.

Fill out as many rows as desired remembering that every row is a case that will run on from the results of the case in the row above it. Fill out the Angles of Attack, Yaw and Speed columns.

  • Click Save.

Once you click save, the Parent Run column will autofill. The Parent Run defines the predecessor run. The Angle of Attacks and yaw should run in a linear sequence. For example in the image to the right, it will run 0 to 5 to 10 deg. The -5 deg will be based off the 0 deg yaw run.

  • After you save, you can Submit All or Submit the runs individually as desired. It is recommended that you submit the first case (0 deg) and make sure it meshes and runs properly before submitting subsequent runs.

Some thought as to how you would like the sweep to progress is important. Here is an example of adding in negative angles of attack. After an initial sweep is submitted (even if it is only one point), then additional points can be inserted to start from a specific run. For example, the image to the right shows two negative angles of attack added that will start from the 0 deg case that has already been submitted. Note that it is required to submit runs before you can insert points.

To insert additional points in a sweep:

  • Select a row and hover over the first column until you see a horizontal double pointed arrow, then right click with your mouse, select insert row, and choose either above or below the selected row. (In the example to the right the row was inserted above.)

  • Insert as many rows as needed and input the additional sweep points in a logical way. The completed insertion is also shown here and the data was inserted so that -4 would run from 0 and then -8 would run from -4. It would not make sense for the angles to be in the order of -8 and then -4 on the next row.

  • After the points are inserted then the changes can be saved and then you can submit the new inserted points.

Another example of when you might want to add points is if you are attempting to locate the stall location of an airfoil and didn't reach it with the initial set of angles of attack and desire to add more. In this case, you would just add them to the end of the sweep.