Reheating in a gas turbine is a process where the air-fuel mixture is partially combusted in a separate combustion chamber, and the resulting hot gases are then mixed with the gases from the main combustion chamber before entering the turbine. This process is typically used in large gas turbines to increase their efficiency.

Reheating has several effects on the performance of a gas turbine, including its impact on the compressor and turbine work. Let's examine these effects in detail:

1. Increase in Compressor Work:
Reheating increases the temperature of the gases entering the turbine, which in turn increases the temperature of the gases exiting the combustion chamber and entering the compressor. As a result, the compressor has to work harder to compress these hotter gases to the required pressure level. This leads to an increase in compressor work.

2. Decrease in Turbine Work:
While reheating increases the temperature of the gases entering the turbine, it also increases the mass flow rate of these gases. This is because reheating increases the overall pressure ratio across the turbine, which drives a larger mass of gases through the turbine. However, since the turbine work is directly proportional to the temperature difference between the inlet and outlet of the turbine, the increase in mass flow rate partially offsets the increase in temperature. Therefore, reheating leads to a decrease in turbine work.

In summary, reheating in a gas turbine increases the compressor work while decreasing the turbine work. This is because reheating increases the temperature of the gases entering the compressor, requiring it to work harder, while simultaneously increasing the mass flow rate of gases through the turbine, which reduces the temperature difference across the turbine and thus decreases its work output.