In 2014 Formula 1 will enter a new era. After three years of planning and development, the most significant technical change to hit the sport in more than two decades is introduced. Engine regulations form the major part of the coming revolution, with the introduction of a new generation of Power Units that combine a 1.6 liter V6 turbocharged engine with energy recovery systems that will dramatically increase efficiency by harvesting energy dissipated as heat in the exhaust or brakes.
The maximum power of the new Power Unit will exceed the output of current V8 F1 engines however fuel efficiency will be radically improved. With only 100kg permitted for the race, the new units will use 35% less fuel than their predecessors.
After a seven-year period during which engine specifications were frozen, the new regulations due to come into effect in 2014 will see engine makers play a central role in the cars’ overall performance. Renault’s new Power-Unit will test the limits of technology and energy recovery within the new regulations.
The countdown to 2014 is already well under way as the Renault Sport F1 engineers turn their attention to the development of what is termed a ‘power unit’ that combines a downsized turbocharged engine with two electric motors to recover braking and exhaust heat energy.
Downsized internal combustion engine
– Switch from a V8 to a V6 architecture
– Cubic capacity reduced by one-third from 2.4 to 1.6 liters
– Turbocharging (single-stage compressor), plus engine torque capped at 15,000rpm for a power output of approximately 550 horsepower
New ‘Energy Recovery System’ (ERS): kinetic energy (ERS-K) and exhaust heat energy (ERS-H) is recovered by two electric motor-generator units named MGU-H and MGU-K.
THE NEW RESTRICTIONS SPECIFIED BY THE 2014 FIA REGULATIONS
A double-restriction concerning fuel
- The amount of fuel that can be used during races has been reduced: the maximum quantity of fuel that may be carried by the car during a race will be reduced to 140 liters. Energy management will become a major factor of race strategies.
- Fuel flow reduced: the maximum fuel flow rate will be reduced to 140 liters/hour, making optimization of every gram of fuel vital for cars to go as fast as possible on a given quantity of fuel.
A double restriction concerning the flow of electrical energy
- The amount of energy that can be recovered during each lap has been reduced
- The amount of energy that can be restored has also been reduced.
Development costs have been limited and the number of engines each driver can use in the course of the season has been further capped: five per driver in 2014, then four per driver from 2015 (compared to eight per driver at the moment). The technologies and materials employed must be similar to those used for production engines.
Downsizing and turbocharging
Turbocharging enables a high proportion of the power to be recovered despite the lower maximum revs limit and the smaller cubic capacity which have a direct impact on the air that flows into the engine. To compensate for the smaller cubic capacity, turbocharging permits the recovery of some of the energy wasted as heat in the exhaust gases to drive the turbo. This energy is then used to compress the intake air (compressor) and increase the pressure inside the cylinders. However, the efficiency of the turbo produces more energy than is necessary to compress the intake air. So, to clear this excessive energy and prevent the turbo from spinning too fast, all turbocharged engines are equipped with a waste gate.
Electrification and double energy recovery system:
The considerable energy contained in exhaust gases as they exit an engine equates to almost 55 percent of the energy provided by the fuel (see “Energy is never lost…” sidebar). This is a huge loss. In the case of the 2014 power unit, however, the motor-generator unit (MGU-H) mounted on the turbo will permit a proportion of this otherwise wasted thermal energy (eliminated via a ‘waste gate’) to be recovered and converted into electricity. This electricity is then stored in the battery or used by the other motor-generator unit (MGU-K) to drive the car. This system will allow the MGU-K to be used for practically an entire lap. This system is known as ERS-H (Energy Recovery System – Heat).
An ERS-K (Energy Recovery System – Kinetic) twice as powerful as today’s KERS and capable of releasing stored energy for 34 seconds per lap Under braking, the kinetic energy of a racecar is dissipated by the brakes in the form of heat. The regulations allow a proportion of this energy to be transformed into electricity via the MGU-K motor generator unit connected to the crankshaft of the internal combustion engine.
This motor-generator unit will be capable of recovering 2MJ (Mega Joules) and delivering 4MJ per lap, which equates to a use for approximately 34 seconds per lap (as opposed to 6.5s/lap in the case of today’s KERS). The MGU-K will be capable of delivering peak power of 120 kilowatts (more than 160 horsepower). This system is known as ERS-K (Energy Recovery System – Kinetic).
Energy is never lost; it is merely converted into another form
The efficiency of a conventional internal combustion engine is approximately between 25 and 30 percent in optimal conditions of use. This means that 70 percent of the energy provided by the fuel combustion is lost in the form of heat, either via the car’s radiators (exchange of heat between the engine block and the cooling fluids) or, more significantly, via the exhaust gases.
“Improving the energy efficiency of an engine entails transmitting as much of the energy produced as possible to the wheels mechanically and re-using as much of the energy resulting from the fuel’s combustion as possible. The aim of the new regulations is effectively to increase combustion efficiency thanks to the combination of downsizing, turbocharging and the recovery of the energy contained in exhaust heat (ERSH) and lost as heat under braking (ERS-K) and then reusing this energy as electricity.” Rob White (Deputy General Manager and Technical Director, Renault Sport F1)