The net work of the cycle is defined by the difference between the turbine work and the pump work: If the pump work is neglected, the net work of the cycle reduces to: Then the thermal efficiency of this system is defined by the rate between the net work and heat transfer from the boiler: Air-Fuel ratio and Air Excess.
At The Airport Valet, we believe that you should only tip commensurate with the service you receive. That said, currently the average tip is $3.00 - $5.00 on both departure and arrival. However, daily our valetsâ tips do range from as low as $1.00 to as high as $30.00.
Upon arriving at or leaving from the airport or train station, tip the standard porter rate of $1 per bag; more if your luggage is very heavy. Typically, a $1 tip for hailing a taxi is appropriate for doormen. However, you may want to tip more for special services, such as carrying your bags.