The temperature of an air stream flowing with a velocity of

Last updated: 6/8/2023

The temperature of an air stream flowing with a velocity of 3 m s is measured by a copper constantan thermocouple which may be approximated as sphere of 3 mm in diameter Initially the junction and air are at a temperature of 25 C The air temperature suddenly changes to and is maintained at 200 C Take p 8685 kg m Cp 383J kg K and k 29 W m K and h 150 W m K Determine i Thermal time constant and temperature indicated by the thermocouple at that instant ii Time required for the thermocouple to indicate a temperature of 199 C iii Discuss the suitability of this thermocouple to measure unsteady state temperature of fluid then the temperature variation in the fluid has a time period of 30 seconds