Early-generation (CR21) equivalent of the fan shroud, directing air through the radiator core.
Superseded by the ducted sidepod, duct and shroud arrangement from CR22 onward, which made the cooling path sealed and predictable rather than open.
No part-specific design process is documented. The Cooling, Aerodynamics subsystem design process applies: 1. Powertrain sets the required heat rejection from previous-year endurance data; that becomes a target mass airflow (CR26I: 0.265 kg/s water, 0.060 kg/s oil). 2. Characterise the core on the flow bench to get pressure drop against velocity, and fit Darcy-Forchheimer coefficients (water radiator viscous 1,919,749.6, inertial 52.945; oil cooler viscous 7,387,951.3, inertial 132.358). 3. Model the core in ANSYS Fluent as a porous region and the fan as a pressure jump over a fan boundary, using the manufacturer fan curve. 4. Sweep radiator angle. CR26I found 0 deg gave 0.459 kg/s with 0.78 lbf drag, +45 deg forward lean gave 0.343 kg/s with 0.31 lbf drag. Forward lean was accepted because it still beat target and cut drag and lift. 5. Design the duct and shroud around the chosen core position, then validate the assembled system with tufting and coast-down testing.
Laid up on a 3D printed mold, printed directly, or formed from sheet.
CFRP, 3D printed nylon, or aluminium.
None recorded. This part has no entry in Knowledge_Transfer/Issue Logging/Fault Vault.xlsx, in either Issue Log.xlsx, in CR22/Issue Tracking/Shakedown 7-15-23.xlsx, or in any design review issue list found in CrimsonStorage or Box.
Replaced by the CFRP duct and shroud package, which cut cooling airside weight and made the mass flow rate calculable.
Nothing in CrimsonStorage covers these yet.