Purpose and Objective: The purpose and objective of this experiment is to understand the basic operation of a brayton cycle also to demonstrate the application of basic equations for Brayton cycle analysis.
Technical Background: The Brayton cycle depicts the air standard model of a gas turbine power cycle and is used in all applications involving turbine engines; such as jet engines. A simple gas turbine is comprised of three main components: a compressor, combustor and a turbine. Air is compressed in the compressor, then mixed with fuel and burned under constant pressure conditions in the combustor. The hot gases created from this process are allowed to expand through the turbine to perform work.
Low pressure air is drawn into the compressor (1) where it is compressed to a higher pressure (2). Fuel is added to the compressed air and the mixture is burned in the combustion chamber. The resulting hot gases enter the turbine (3) and expand out the tailpipe (4). The Brayton cycle consists of four internally reversible thermodynamic processes (see the figure above):
1-2 isentropic compression in the compressor ()
2-3 constant heat addition in the combustor ()
3-4 isentropic expansion in the turbine ()
4-1 constant heat rejection in the tail pipe ()
Equations used:
T=Temperature, W=work, q=Heat, ƞ=efficiency, k=1.4, =1.005KJ/KG
Experimental data taken:
In this experiment, data should have been recorded when goal RPM was at 105 (x1000) but during the experiment the engine failed due to unknown reasons. At point T4 during 35 (x1000) RPM, the number originally recorded was incorrect due to reader error so 475 (Deg. C) was used to simulate the correct number.
Results:
According to the graph above; as the RPM of the engine reaches a higher number the efficiency of the engine increases. This means that the work done by the engine increases at
References: http://en.wikipedia.org/wiki/Brayton_cycle http://web.me.unr.edu/me372/Spring2001/Brayton%20Cycle.pdf Lab handout