TS Aero Geometry

This section will cover the following topics on this page. (Clicking on the Sections will open a new page.)

VTOL

Adding Propeller Curves

The project settings must be updated with a valid propeller curve before a run can be successfully created for a geometry with a propeller assembly. TotalSim has provided an excel sheet for you to generate propeller curves, if you don't have one. Please note that data generated by that excel sheet can only be used as a placeholder and results generated by the excel sheet is not representative of your vehicle's performance. The excel sheet can be found at the bottom of this page.

Go to Project Config at the navigation menu on the left

Click on the drop-down arrow next to Propeller Curves.
Enter a propeller curve name (it can be anything, for example: DEFAULT).

Enter the RPM, Velocity at Propellers, and Thrust data for the propeller (copy from an Excel file). Example data is provided in the spreadsheet to the right. (Double click or click on the first cell and then press <F2> to input data. Data can be copied and pasted into the table.)
Click Save.
Click on Add Propeller Curve to upload additional propeller curves.
For the same Propeller Curve Table, you can enter curves for multiple RPMs. The app has the ability to interpolate across RPMs.
Additional information regarding the Propeller Curves can be found here.

Geometry Information for Uploaded Parts

The geometry can be split over three files. There are three types of parts are Default, Payload, and Hub; therefore, a separate file needs to be created for each of these geometry types and include only the appropriate parts for that category. Do not duplicate parts across the geometry files to be used in one simulation.

Use the instructions on the 'Uploading Geometry' page to upload parts. For each part (geometry file) you upload you will be required to select a geometry type. The following is a list of available types:

Default - Any geometry that is not a Payload, Hub, or Propeller.
Payload - Any geometry that is part of the payload.
Hub - Any geometry that is part of the propeller hub.

Note: Please do not upload part files for any propeller geometry. In this App, propellers are modeled numerically. You will find information on creating propellers below.

Be sure to separate your geometry into these groupings prior to upload. All files should be the same scale and the relative position of the parts should be consistent across all files.

Hub Parts

Geometry should be considered a hub where the center of the propeller intersects spinning support geometry. It is recommended that geometry be prepared this way because additional detail is applied to the intersection between the hubs and the propeller disk. In the tricopter example, the hubs have been split from the main assembly as shown below

Creating Propellers

Creating Dummy Propeller Part

This propeller part will act as a dummy part for a single/multiple propeller assembly.

Click on Parts then Create Basic Part button (middle button) and give it a name. Note: Basic Part names can not start with numbers or special characters.
Click on the part you just created and change the type to Propeller.

Enter the Radius and select the units.
For the Center point, I would suggest entering (0, 0, 0) for simplicity.
Enter the Thrust vector. The coordinate system is shown on the right.
Enter the desired Propeller Curve Table Name (created above under the Project Settings).
Click Save.
Click on the Assemblies tab.
Click on Create Assembly and give it a name. Note: Assembly names can not start with numbers or special characters.
Click on the assembly you just created..
Change the type to PropellerAssm.
Enter the coordinates of the propeller(s) you want to create as deltaX, deltaY, and deltaZ in millimeters from the propeller you generated the Parts section. If you entered (0, 0, 0) for the generated propeller part, this will just be the coordinates from your CAD software.
Enter the Trust Vector for each propeller.
Note: Each line of data entered is equal to one propeller that the assembly will generate (so 6 rows of data will generate 6 propellers).
Click on Save.

Click on Edit Parts under the Assembly
Select the Propeller you generated under the Parts section.
Click on Save
Repeat this Section if you have propellers with multiple radii.

Airfoil

Geometry Information for Created Parts

For the Airfoil tool, the airfoil geometry is input as coordinate sets using the create parts option. (Currently, coordinate set input is the only supported format.) The coordinate set(s) is then used to generate a surface (or surfaces for multiple elements) which is used for analysis.

How the coordinate set(s) must be created:

The coordinates need to be scaled in meters.
The leading edge point should be located at (0, 0) for the most forward wing part.
The coordinates must be entered such that the first ordinate is in the chord-wise direction and the second ordinate is in the thickness direction. This application sees these as (x, z) pairs.
Coordinates must be ordered such that they are continuous around the airfoil section. See the diagram to the right describing this. The first and last point of the ordered set will be connected when generating the surface mesh; therefore, they should not be the same point.
Due to the methods used for volume meshing, it is necessary that there not be any sharp edges on the airfoil. The trailing edge and any other feature edges must have thickness no less than 0.2% of the chord. For example, if the chord length of the airfoil is 1 m then the minimum thickness of the trailing edge is 2 mm. Obviously, thicker trailing edges are acceptable.
Each element will be entered as a separate part. Be sure that each of the elements are located in the proper position relative to each other when input (i.e. the leading edge of the second element will be at some point other than (0, 0)) so that if they are plotted on the same graph then they will show proper relative position to each other.
Currently the application does not have any kind of spline feature; therefore, it is important that the user create (or obtain) a coordinate set that is well defined.
- The application makes no assumptions about the underlying geometry; it uses the points as input by the user to create the surface stl required by the mesher. Therefore, if the points around the leading edge are not fine enough to define the leading edge curve, then a faceted and/or pointed leading edge can be the result. (See the image to the right for what can happen if there are not enough points to well define the leading edge.)
- This Airfoil Tools web site is recommended for obtaining airfoil coordinates. Often the data base coordinate sets a have too few points to generate a well defined airfoil. Therefore, it is suggested that a spline function be applied to the coordinates to obtain more finely spaced points. However, the 4 and 5 digit airfoil generators are capable of creating 200 points with a cosine spacing (for a nicely defined leading edge) and this is usually sufficient enough to create a well defined geometry. Be aware that coordinates downloaded and generated on this web site will usually have a pointed trailing edge. You MUST blunt the trailing edge to no less than 0.2% of the chord as described above before uploading them into the application.
- The mesher will only capture 0.0015625*chord spacing in the high curvature regions like the leading edge and will have 0.003125*chord spacing over the rest of the airfoil. The spacing of the input coordinate set needs to be no finer than these guidelines.
- It is recommended that prior to inputting an airfoil the user plot the points with straight lines between to be aware of how the airfoil will be represented when the surface is created.

Example of user coordinate position inputs.

Example of what happens when not enough points are used to define the airfoil leading edge region.

Geometry Input as Created Part

Each element of the airfoil is entered as a separate part.

To input a data set select Geometries and then select Create Basic Part (middle button). Name the element as desired. For example main, flap1, flap2, etc. Note: The part names cannot start with numbers or special characters.
Once the part is created, it must be edited to input the coordinates. Select the part that was just created in parts-manager; choose the three dots to the right and select Edit. (See image labeled "Edit Part")
During editing the part, select the part type as Airfoil. Double click on the first entry for the airfoil coordinates and either enter by hand or copy and paste a set of coordinates into the table.
Once all the coordinates are input into the table, scroll to the bottom and Save the coordinates

Note: Because of the 2D nature of the data, you will not be able to view the airfoil in the viewer. Be sure you are confident in your coordinate data set before inputting them.

Repeat as necessary for multiple element cases.

Within the simulation, the user will also be expected to include the reference chord length of the airfoil which will be used for meshing and results purposes. For multi-element cases it is up to the user to decide if the chord length is the length of the main element or is the overall length of all elements together.

Results are coefficient values and are non-dimensionalized by chord length and flow conditions.

Free-Flight

Geometry Information for Uploaded Parts

The geometry can be split over multiple files. There are seven different types of parts; therefore, a separate file needs to be created for each of these geometry types and include only the appropriate parts for that category. Do not duplicate parts across the geometry files to be used in one simulation. Be sure to confirm that your uploaded geometry has forward-facing direction in the -X axis direction of it's coordinate system. A MainWing part is required for the simulation.

Use the instructions on the 'Uploading Geometry' page to upload parts. For each part (geometry file) you upload, you will be required to select a geometry type. The following is a list of available types:

Fuselage (default settings) - This is the main body of the aircraft or vehicle.
WingElements - This would include any flaps, pylons, and slats that is part of the Main Wing. Flaps can also be uploaded as a Hinge Element.
Tail - This type includes the horizontal and vertical stabilizers. Rudder can also be uploaded as a Hinge Element.
Engine - This type is associated with the outer casting of an aircraft engine.
Spinner - Any geometry that would typically spin (ie. wheels).
LandingGear - It includes any geometry associated with the landing gear system including any struct and truss.
MainWing - This is a required geometry for the simulation. It includes only the main wing geometry. Any other part associated with the main wing is assigned as a Wing Element geometry type.
Radiators - The radiator type is made up of two parallel planes that represent the up and down stream faces of the actual radiator core. This will need to fully intersect the geometry around it so that it forms a fully sealed volume. More information can be found here.
Hinge-Element - Any part that can rotate about a rotational axis. The app will report the moment forces on the hing-element relative to the rotational axis. The hinge-element angle can be configured in the application settings when it is selected as part of a simulation. Any control surface, including flaps and rudder, can be uploaded as a Hinge Element geometry.

Be sure to separate your geometry into these groupings prior to upload. All files should be the same scale and the relative position of the parts should be consistent across all files.

Details for Required Geometry Attributes

Inputs are required for three of the geometry types: MainWing, Hinge Element, and Radiator.

MainWing

The chord length is generally the Mean Aerodynamic Chord and should be entered in meters. The wing area should be entered in squared meters. The main wing type can have multiple files if uploading slats, flaps, and pylons separately.

Note: If uploading flap, slat, and pylon geometry separately, the attributes will just be the same as the attributes for the main wing.

Hinge Elements

The starting and ending points (meters) of the rotation axis are required for each Hinge Element geometry. The App will rotate the Hinge Element geometry by the rotation angle (entered in Run Setup) about the Rotation Axis defined in the Geometry Attributes.

Radiator

Required inputs include the normal direction vector of the downstream face of the radiator, the Inertial Coefficient, and Viscous Coefficient of the Radiator are also required.

Additional details for radiators can be found here.

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