Gordon Murray T50 Aerodynamics - Successor to the McLaren F1 supercar

For more information, visit https://www.airshaper.com or email info@airshaper.com ---------------------------------------------------------------------------------------- To understand the advanced aerodynamics behind the T50, let’s travel back into time to some of Gordon Murray’s most famous creations. Legendary cars by Gordon Murray --------------------------------------------- Brabham BT46 Inspired by the ground-effect Lotus Type 78 featuring side skirts and the Chaparral 2J “sucker car”, featuring 2 fans at the rear, Gordon Murray and the team installed a massive fan at the rear of the Brabham Formula One car. Because ‘moveable aerodynamic devices’ were not allowed, its official purpose was actually to improve cooling, which it did. What it unofficially also did, was to draw air from underneath the car. With side skirts around the car closing off the underfloor area from the outside air, the fan was able to maintain a low pressure underneath the car. This led to high amounts of downforce, enabling crazy cornering speeds. McLaren F1 On sports cars, you’ll often see a diffuser, the upward sloped rear part of the underfloor. It’s there to increase the airspeed underneath the car, which will help to create suction because of the Bernoulli effect. If the upward angle is too aggressive, the air will not be able to follow the curvature and will continue on its own, more horizontal path. This is what we call a “stalled” diffuser. To activate it and make the air follow the curvature, the fans draw air away at the beginning of the diffuser step. This helps to remove the boundary layer and makes the airflow stick to the underfloor surface. It increased downforce by 5% and reduced drag by 2%. Aerodynamic analysis of the Gordon Murray T50 ---------------------------------------------------------------- Fan The fan has an 8.5kW electric motor and can spin up to 7.000 rpm. It will eject the air into the wake behind the car, helping to reduce drag by virtually creating a long-tail car. And the 15kg of thrust it produces is around 2.5% of the total drag on the car, so that effect is actually significant as well. Even more so – from what we understand from various interviews, it’s actually more efficient to provide 8.5kW to the fan and not to the drive shafts to increase top speed. Now let’s see how the fan works together with other parts of the car in different aero modes. Downforce mode In down force mode, the fan will source air from the diffuser channels. The car has 2 very pronounced diffuser channels which fit between the engine bay and the rear wheels. They are so high that the exhaust system of the engine was actually moved upward to make room for them! Another consequence is that the suspension arms and even the drive shafts need to cross the diffuser channels to get to the wheels. That’s why the suspension arms have been given an aerodynamic profile, just like in formula One and Indycar, to limit their impact on the airflow. On the official CFD, or computational fluid dynamics, images we can again see an aggressive step at the beginning of the diffuser, similar to the one we saw on the McLaren F1. Without fan assistance, the air is not able to follow this profile and the diffuser stalls, creating just a mild diffuser effect. But in downforce mode, the fan draws its air from the beginning of the diffuser, at the steep part of the step. This helps to remove the boundary layer and to make the air to stick to the profile. This not only creates downforce at the rear, it also helps to accelerate the air underneath the entire car, creating down force at the center and front of the car as well. That eliminates the need for a big splitter at the nose to correct the aero balance, which is the split between downforce at the front and rear. Also in downforce mode, the aerofoils or flaps at the rear of the car tilt upward. In total, down force mode will generate 50% more overall downforce on the car. Streamline mode The rear spoilers drop by 10° to reduce base suction, which is the pressure just behind the car, holding it back. And the fan will now source its air from the top air inlets. This again helps to remove the boundary layer which will help to reduce drag on the parts downstream of these inlets. Together with the virtual long-tail effect, drag is reduced by an impressive 12.5% in streamline mode. Vmax mode This is basically the same as streamline mode, but the fan is now powered by the battery instead of the engine, to free up engine power. Brake mode The flaps rise even further to their maximum angle of 45°. This mode provides a 100% increase in downforce, which provides more grip for braking. And because the flaps are positioned relatively high on the car, the drag on them creates a backward tilting moment, counteracting the forward tilt caused by the deceleration. This greatly improves the balance of the car under braking. All this reduces the braking distance from 150mph to standstill by 10 meters.

Awards and Support

  • Solar Impulse
  • iMec
  • Voxdale
  • Professional MotorSport World Awards – MotorSport Technology of the Year

Code contributions by

  • KU Leuven
  • Inholland
  • Linkoping University