temperature not changing!
 

Hi all, I am doing a engine simulation with mesh derived from es-ice and I discovered something very strange during the calculation.

1.if the calculation starts after the intake valve closing, temperature stops to change after several crank angles, even if the piston is moving upwards.

2.if the calculation starts before the exhaust valve closing,the same problem still occurs after the closing of intake valve, temperature distribution not changing any more.

3.in the calculation, i use 1-step reaction, and the scheme is associatied with the ports as well as with the cylinder, in case of backflows.the reaction is set to be triggered at the temperature of 1050K. i found that combustion products are generated in intake port only, where the temperature is much lower than the cylinder and exhaust port. what's more, none of these places has reached the temperature of 1050K!(at this time, the temperature has already failed to change)

Would somebody help me to find an explanation for this? Many Thanks!