What is time constant ? The steel ball bearings of 40 mm diameter and initially at uniform temperature of 600 °C are quenched in an oil bath maintained at 50 °C temperature. The heat transfer coefficient between the ball bearing and oil is 325 W/m²-K and the thermodynamics properties of the bearing can be taken as : k 45 W/m-K and thermal diffusivity a = 1.25 x 10- m/s. Determine: a. The time duration for which bearing must remain in oil to attain 225 °C temperature. b. The instantaneous heat transfer rate from the bearings when they are first immersed in oil and when they reach 225 °C.

What is time constant ? The steel ball bearings of 40 mm diameter and initially at uniform temperature of 600 °C are quenched in an oil bath maintained at 50 °C temperature. The heat transfer coefficient between the ball bearing and oil is 325 W/m²-K and the thermodynamics properties of the bearing can be taken as : k 45 W/m-K and thermal diffusivity a = 1.25 x 10- m/s. Determine: a. The time duration for which bearing must remain in oil to attain 225 °C temperature. b. The instantaneous heat transfer rate from the bearings when they are first immersed in oil and when they reach 225 °C.

Biomedical Instrumentation Systems

1st Edition

ISBN:9781133478294

Author:Chatterjee

Publisher:Chatterjee

Chapter9: Instrumentation In Blood Circulation

Section: Chapter Questions

Problem 12P

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