Efficiency of Gas Turbine

Efficiency of Gas Turbine is defined as the ratio of workdone due to adiabatic expansion to the workdone due to isentropic expansion. In Fig. 5.17 (a) and (b), the cycle 1-2-3-4 represents the ideal cycle and 1'-2-3'-4 represents the actual cycle of a closed cycle gas turbine, in which the curve 4-1' shows the isentropic compression of air in the compressor and the curve 2-3' shows the isentropic expansion of air in the turbine. The turbine efficiency (also called adiabatic efficiency of turbine) is given by

The compressor efficiency (also called isentropic efficiency of compressor) is the ratio of workdone due to isentropic compression to workdone due to adiabatic compression. Mathematically, compressor efficiency,

Note: The efficiency of a simple gas turbine can be increased by using the following methods.

1. By compressing the air in two stages with an intercooler between the two.

2. By expanding the hot air in two stages with a reheater between the two.

3. By providing a heat exchanger through which hot gases from the turbine are made to pass which heat up the compressed air before entering the combustion chamber.

Are Engineers Favourite Among Girls?

What do girls think about men who are engineers and what type of engineers are most favourite among girls? A survey was conducted by a team of aboutmech with members chosen from different countries. Each team member carried out a neutral survey in his/ her country to evaluate what females think about most of the engineers from different engineering branches. An overview of different questions asked in survey is given below: Question: Which male engineers do you find more attractive as a husband? Almost 50% women voted for mechanical engineers to be the most attractive husbands among other engineers. So mechanical engineers are most favourite among girls as a husband. They find them more trustworthy, intelligent, and creative. A married women from California said, “If your husband is a mechanical engineer, he will help you in everyday tasks. Because mechanical engineers are good team players and they have creative ideas about everything.” Which male engineers do you find more