Electric cars to evolve?

Image result for VW with Lowest Drag

Aerodynamicists largely got their own way during the design of this working low drag prototype.  The ‘Pink Shirt’ designers still wanted a few styling creases stamped into the body though.

Air likes to travel in graceful curves.  Unfortunately mechanical parts are odd shaped and need to placed in the right position within the car.  Human beings also like to be placed in vehicles so they can see out and feel comfortable.  Finally fuel tanks have to be placed where they will not be damaged if the car is involved in an accident.  Getting this lot packaged so everything works, occupants are safe and comfortable and fuel tanks don’t burst into flames if the odd accident should occur –  this a tall order for the aerodynamicists trying to design low drag vehicles.

If it was practical to place fuel  in nooks and crannies which could not be used for any other purpose, then over 40 litres of space could be liberated.  Further space saving would be possible if engines generated high torque from rest.  This would eliminate bulky gearboxes.

 

chevy-350-400-hp

 

This 400hp internal combustion engine will occupy a large engine compartment and needs a gearbox. The total volume of the Tesla power plant is about the same as the air filter on this engine.  An electric motor has just two bearings.  There are scores in this internal combustion  engine.

 

Finally if powerful engines were tiny and efficient, space could be saved by placing motors in or near the wheels thereby making prop shafts and differentials redundant.  I would estimate that the  space available for passengers could be increased by well over a hundred litres.  By now, dear reader you have undoubtedly twigged that battery electric motors are the solution

Now electric motors can also act as generators.  Four wheel electric drive motors can apply retardation very precisely  when controlled by electronics and sensors.   Disk brakes will still need to be fitted to the wheels but they will have an easy job so may be light in weight.  Lower unsprung weight will improve ride quality.  Neither will they need unsightly air scoops to cool them since most of the cars’ kinetic energy will be recuperated into the batteries.

The aerodynamicists would have a field day unencumbered with the constraints of mechanical lumps to be enclosed in smooth streamlined shells.  Gawping holes in the front needed to cool inefficient petrol engines would not be needed therefore designers could avoid these sources of turbulence.   Floor pans could be as flat as those found on Formula 1 racing cars; drag coefficients could be halved and  car bodies would have a beauty generated by their functionality.  Unfortunately the ‘Pink Shirts’ designers would insist on the usual paraphernalia of superfluous creases and air scoops to give  their designs ‘road presence’  a term used to give cars an ‘angry face’ aping the faces of attacking carnivore

 

This hot hatch  has exaggerated air cooling scoops, the current fashion adopted by car designers.  They do nothing to smooth the air flow round the vehicle.

 

Cars designed to have a low aerodynamic drag will of course allow them to go faster – and every driver likes to have bragging rights.  Hopefully low drag may become  more prominent in sales literature since in the case of electric cars, this extend range.

Now some readers might consider that travelling in a box of lithium batteries to be somewhat risky.  Please may I point out that firing an incendiary round into a petrol tank is usually quite spectacular.  Repeating the experiment on a fully charged lithium iron phosphate battery does it no good.  However there would be no fire and the battery would probably still work for a while.

Tesla Model ‘s’ batteries were originally designed to be swapped over in a few minutes.  There was talk of batteries wearing out.  In practice this fear was unfounded due to manufacturing improvements .  Admittedly the occasional cell may fail but overall they are ‘fit and forget’.  There are no mechanical parts  to wear out.  Odd spaces could be filled with 21mm x 70mm cylindrical nickel free cells or perhaps prismatic cells shaped to exactly fit the space available.

Image result for 21700 batteries

Now Tesla have bragging rights on the drag strip.  Moving all that energy from around the vehicle  requires heavy copper wiring.  This could be eliminated by mounting super capacitors near the motors.  These would drive the motors directly through short thick conductors and have sufficient energy to launch the car up to 60mph.  These capacitors would then be recharged at a relatively slow 40kw or so from the storage batteries allowing the slippery car to cruise at a leisurely 100mph.

Please may I finish with a gripe about huge 4×4’s.  They are fuel guzzlers and very bad for the environment.  They are not the best tool to be used on the school run.  The mechanical four wheel transmission means that the turning circle is poor making them cumbersome.  They are also prone to falling over if driven enthusiastically. By employing electronically regulated motors to each wheel, the vehicle can have far better traction than a conventional 4×4.  and the power can be vectored to maintain the best stability possible round bends.

Riot police officers and other people assist the governor of Boyaca, Carlos Amaya (in vehicle), after a road accident between the cities of Tunja and Duitama, Boyaca Department, Colombia, on July 12, 2016. According to a statement released by Boyaca' Government press office citing witnesses, his caravan collided with "obstacles put in the way by striking truck drivers. / AFP / Edwin Camargo (Photo credit should read EDWIN CAMARGO/AFP/Getty Images)

This 4×4 fell over revealing the components beneath the car.  These ugly lumps of steel cause wind turbulence and therefore increase fuel consumption.

 

The Government has decreed that new cars sold will be  electric  by the end of the decade.  I, for one hope that these vehicles lose their internal combustion engine roots.