Consider the following statements in respect of gas turbines:1. Supers...
Correct answer is A,
concept chocking.
If the flow reaches Mac number 1 once then whatever we do we can't increase mass flow rate.
and due to supersonic flow isentropic efficiencies of compressor and turbines decreases there by decreasing in overall efficiency
Consider the following statements in respect of gas turbines:1. Supers...
Supersonic Flow in Gas Turbines
Introduction:
Gas turbines are widely used in the power generation industry because of their ability to produce large amounts of power with high efficiency. The working principle of a gas turbine is based on the Brayton cycle, which involves the compression of air, combustion of fuel, expansion of hot gases, and exhaustion of the resulting gases. Supersonic flow is a phenomenon that can affect the performance of gas turbines, and this article discusses the impact of supersonic flow on gas turbine efficiency and flow rate.
Supersonic Flow and Efficiency:
Supersonic flow occurs when the velocity of a gas exceeds the speed of sound. In gas turbines, supersonic flow can occur in the compressor, combustor, and turbine stages. When supersonic flow occurs, it can cause shock waves to form, which lead to a decrease in efficiency. This is because shock waves cause a sudden increase in pressure and temperature, which can damage the blades of the turbine. Therefore, gas turbines are designed to operate at subsonic speeds to avoid the negative effects of supersonic flow.
Supersonic Flow and Flow Rate:
The flow rate of a gas through a gas turbine is determined by the velocity and density of the gas. When supersonic flow occurs, the density of the gas decreases, leading to a decrease in flow rate. This is because the gas expands rapidly when it passes through the shock waves, causing a decrease in its density. Therefore, gas turbines are designed to operate at subsonic speeds to maintain the desired flow rate.
Conclusion:
Supersonic flow can have a negative impact on the performance of gas turbines. It can cause a decrease in efficiency and flow rate, which can lead to a decrease in power output. Therefore, gas turbines are designed to operate at subsonic speeds to avoid the negative effects of supersonic flow.
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