Automotive gas turbines

Automotive gas turbines:
-First gas turbine car is JET1 with speed record of 243 km/h
-Then car with heat exchanger was developed to attain speed of 163 km/h and also Rover BPM-car was introduced
Advantage of automotive gas turbines;
-thermodynamic advantage of complete expansion
-Mechanical simplicity i.e. fewer moving parts compared to reciprocating IC engine
-Smooth and vibration less power delivery
-Specific weight is 10-20% less than SI engine
-Low emissions
-Easy cold starting
-High mechanical efficiency of 85-90%
-Cheaper fuels are used
Disadvantage of automotive gas turbines;
-Lower thermal efficiency due to lower temperatures and compressor efficiency than reciprocating IC engine
-Part load efficiency is very poor
-Difficulties in throttle operation due to high rotor speed
-High initial cost
*Arrangements of automotive gas turbines:
(a) Single shaft configuration: single expander turbine to drive both compressor and drive train on a common engine shaft
-less weight, low cost and better efficiency
-incapable of meeting highly variable operating conditions
(b) Twin shaft configuration:
-Turbo-compressor is mounted on one shaft and power turbine is mounted on another second shaft which provides power to the wheels via transmission