function of turbine
Answers
Explanation:
A turbine is a steam-powered machine that causes a shaft—a rotating rod that transmits power or motion from the turbine—to produce electricity through movement.
Answer:
Variable geometry turbines
Turbines may also incorporate variable geometry and this is usually applied to power turbines where the nozzle guide vanes (NGVs) are turned to alter the flow capacity and thus the turbine characteristic. Variable geometry has been employed in turbines operating with free power turbines to improve the off-design thermal efficiency (i.e. low power outputs), particularly when a heat exchanger is added. Variable geometry power turbines also provide improved acceleration when the NGVs are full opened and can also be used to provide substantial engine braking when the NGVs are rotated sufficiently, such that the gases leaving the NGV impinge on the turbine rotor in the opposite direction.
The prediction of the off-design performance of gas turbines employing variable geometry turbines requires an additional estimate and check vector, which correspond to the NGV angle and the required exhaust gas temperature, respectively. The exhaust gas temperature may be measured downstream of the gas generator turbine rather than at the power turbine exit. It is also necessary to know the change in the turbine characteristic with NGV angle, and the appropriate turbine characteristic must be used as the NGV angle changes during the iterations described above