E-Mobility Engineering 017 l ECE Doosan electric excavators dossier l In Conversation: Matt Faulks l Battery testing focus l Battery Show North America 2022 report l Ariel Hipercar digest l Cathode materials insight l Thermal management focus

the front, to allow for rapid design changes without having to replace expensive moulds. Saunders adds that the car is around 200 kg overweight because of the 3D-printed panels, so on that basis the production Hipercar should accelerate even harder than the prototype, aided by further weight reduction from the use of carbon fibre wheels in place of the forged alloy items. “If we just replaced everything with carbon we would be just over 1500 kg,” he says. “So we want to get it under 1500 kg, which for this sort of car is light.” Aerodynamics have shaped the body to balance drag reduction against downforce, stability and thermal management, and Ariel has worked closely with TotalSim to develop the Bramble computational fluid dynamics system used to help design the car’s aero. Air is channelled over, under and through the bodywork with, for example, two large heat exchangers for the thermal management system and four fans prominent across the rear. Other examples include the fins on the front wings that reduce drag on the mirrors, the roof scoop that supplies air to the Cat Gen and the Le Mans Prototype-style central fin and the ‘shark fins’ on the rear wings to aid stability and cornering. Testing remains a central part of the development programme, and has encompassed WLTP and abuse tests, thousands of simulated laps on race circuits, plus sessions in climate chambers, shaker rigs, noise, vibration and harshness and electromagnetic compatibility testing. Ariel has also worked on multiple computer simulations, cooperating with TotalSim to refine the aerodynamics, and on both the FEA and safety with Tecosim. “We probably have another year or two before the car is ready for sale,” Saunders says. “There is a lot of detail development, testing, reliability and endurance testing still to do.” control, while the production car will feature adjustable torque vectoring, enabling the motors to drive the wheels at different speeds to further improve cornering performance. The motors also serve as a regenerative braking system, both to improve the Hipercar’s energy efficiency and to add an extra element of driver involvement, as the level of regen is adjustable with paddles on the steering wheel, and can be turned off. Structure and bodywork The Hipercar has an aluminium alloy chassis, which Ariel describes as a laser-cut and CNC-folded, bonded aluminium monocoque. Attached to the front and rear of the chassis are aluminium subframes that serve as crush structures and suspension mounting points. While the production version will have bodywork moulded completely from carbon fibre-reinforced plastic, the prototype uses several 3D-printed panels, particularly at Aluminium alloy is the dominant material in the chassis, with a CNC-bonded and folded tub and front and rear subframes, while production bodies will be all CFRP (Courtesy of Ariel Motor) January/February 2023 | E-Mobility Engineering 57 Digest | Ariel Hipercar