Naming Conventions for Bicycles
In the fast-paced world of aerodynamic high performance bike design, consistency in file naming might seem trivial, but for CFD engineers optimising airflow around every tube and spoke, it’s essential. Well-structured naming conventions for CAD files and components can significantly enhance workflow efficiency, ensure accurate meshing, and enable better collaboration across design and simulation teams.
This guide outlines a structured approach to naming zones for CFD cycling simulations, helping aerodynamicists and CAD designers stay aligned from rim to rear triangle.
Why zone names matter in CFD
When a new bike part is introduced into your CFD workflow, whether a brake calliper, a bottle cage, or an aero handlebar, the ‘zone’ name must be specified. Within bramble the ‘zone’ name is used to set boundary conditions and determine mesh recipe for that part.
Our CFD software also uses the naming ‘zones’ to auto-configure aspects of the simulation setup. Getting it right means faster runs and more reliable results.
The basic format for naming conventions
This is the basic format for ‘zone’ names:
<zone>-<description>
<zone> matches a predefined list of names, and <description> can be whatever the user wishes but only allows letters, numbers and hyphens; no spaces.
For example:
frame-top or frame-front
You’ll find a description of the standard names further down the page.
In order for the kinematics to work correctly, specific descriptions are required for the wheel components. Similarly, internal flow planes (such mass flow planes and wheel MRFs) need to zone “toint” (pronounced “to – int”. These are also covered in more detail further down the blog.
Kinematics
The example shows a rear wheel, using the same naming convention for the front wheel (just replace “rr” with “fr”).
For example
All other components that rotate with the wheel should be called:
rr-wh-<description> (e.g. rr–wh-rim)
- rr-wh-hub
- rr-wh-tyre
- rr-wh-brake-disc
- rr-wh-rim
Default – zone names
- handlebar / stem
- saddle
- seat-post
- frame
- rr-wh
- gear
- fr-wh
- forks
Additional – zone names
“toints”
Within a CFD model it is necessary to separate out specific regions (e.g. the fluid between wheel spokes), or to measure flow rates passing through a location. Our in-house engineers use a special zone name called “toint” to define these regions. which comes from the shortening of “to interior”.
Specific zone names are:
- Wheel RRFs: toint-rrf-<description> e.g. toint-rrf
- Mass flow planes: toint-mfp-<description> e.g. toint-mfp-fr-br-duct
Why consistent naming makes a difference
If your CFD model is to be reused across wind tunnel tests, parametric studies, or generational upgrades of a bike model, a repeatable naming convention allows quick zone swaps, batch meshing, and automated scripting for simulation runs.