16 July 2018
'Energetic Numbers' proved to be a tour de force from club member George Hunter. His talk ranged far and wide in pursuit of an understanding of the uses and abuses of energy in our world today.
Much of the talk focussed on cars and we started of with a look at a Ferrari 488 Spider - an extreme machine producing some 660 brake horse power and able to accelerate from 0 - 100 kilometers per hour in just about no time at all! Not a car for the school run.
We went on to hear about thermodynamics and the actual limits that exist on improving the efficiency of internal combustion engines.
George showed that more than half of all fuel used in a car is lost - it is not used to propel car and passengers. Even with the best engine designs available today, a diesel engine might achieve 45% efficiency and a petrol engine just 39%. This compares with 66% for a steam turbine, which is the most efficient converter of energy we currently have.
More facts and graphs were revealed, demonstrating exactly where the losses happen, from friction to combustion cycle, to wind resistance to accessories like air conditioning.
The talk concluded with hints and tips for more economic driving, with graphs showing that steady speeds around 40 - 60 mph and the avoidance of harsh acceleration are best.
Altogether an intriguing and thoughtful talk - and one that addressed a vital topic of today's world.
Following questions a vote of thanks was proposed by Bill Batchelor.