I know that increasing the turbine inlet temperature (TIT) increases the overall efficiency of the jet engine. So I wanted to find the overall efficiency as a function of TIT. I used the equations from this website. But the efficiency seems to go down as I increase the TIT. I have attached the pictures of the functions I used to get the graph.
I assumed a compressor pressure ratio of 30, a fan pressure ratio of 1.5 and a bypass ratio of 8.
stages of the cycle the way I defined it as 1-2 is inlet 2-3 is compressor 3-4 is combustor 4-5 is a turbine 5-6 is afterburner(I didn't use it so 5 and 6 are same) 6-7 is the nozzle
I have also found another picture from this website that showed the similar result with efficiency going down as TIT is increased
Can someone please tell me what I did wrong? Or if you can provide a similar graph with similar assumptions that would be great.