Pull air through the radiator core when the vehicle is not moving fast enough to do it, which is the worst case the whole cooling system is designed around.
A 9 inch Spal VA07-AP12-/C-58A fan mounted in the CFRP shroud on the back face of the radiator. Activated automatically at 96 C water inlet temperature, which minimises power draw, decreases warmup time and removes the dependence on the driver to switch it on.
Selected from the fan curve against the radiator's pressure drop curve, with the resulting operating point giving the mass flow the NTU sizing assumed.
Combined cooling fan current draw is capped at 15 A by the electrical budget. Water fan plus oil fan sit at 12.6 A combined, 2.4 A below the allowance.
Represented as a pressure jump over a fan boundary condition in the ANSYS Fluent cooling model, using the manufacturer fan curve.
Purchased.
Purchased unit. From the cost report drawings and CAD: From the cost report drawings: Plastic (Radiator Fan).
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.
Approximately 543 CFM according to the fan curve and radiator data. Weight 2.2 lb, 1.53 lb lighter than CR22's four 140 mm PC fans. Maximum current draw 8 A normal use, 16.0 A on start. From the design reports and one-pagers: CR22 fans: Bgears 140 mm, 308 CFM each, 2.76 A draw each, roughly 1 lb. Chosen for a high CFM-to-size ratio and low amp draw. Four of these were replaced on CR26I by a single 9 in Spal unit. CR25 single radiator one-pager costed the Spal fan at about $75 against a new custom radiator at about $500. From the cost report drawings and CAD: Dimensions called out on the cost report drawings. These are the figures printed on the drawing, not a labelled specification; open the drawing itself for what each one refers to. Radiator Fan (mm): 110.0, 7.0, R7.3, R69.9, R72.5, 29.8, 56.3, 144.9 VA07-AP12_C-58S-A (as drawn): 8.000.80, 48.00, R4.80, 51.80, 5.18, 246.00, 24.60 Source: Cost report drawings: CR26E/Powertrain - EV/Design/Cost Report Drawings/Cooling/Radiator Fan.pdf; CR26i/Powertrain - IC/Design/Y - Cost Report Drawings/Cooling/VA07-AP12_C-58S-A.pdf; CR27i/.Powertrain/Design/Y - Cost Report Drawings/Cooling/Archive/VA07-AP12_C-58S-A.pdf Quantity per car, as costed: 1, 2
Nothing in CrimsonStorage covers these yet.