CHEMENG 3A04 Lecture Notes - Lecture 5: Lumped Element Model, Thermal Mass, Dimensionless Quantity

• School: McMaster University
• Department: Chemical Engineering
• Course: CHEMENG 3A04
• Professor: Phil Wood

Document Summary

In practical terms, very few processes operate at a true steady-state. Noise caused by controller accuracy and/or mechanical variation inherent to the different pieces of equipment that make up the process. processes such as this may be considered to be at steady state. For other processes, disturbances consistently arise, causing the controller to continuously adjust to search for the specified set-point. processes such as these virtually always operate in transient mode. dt/dt 0. Transient conduction may be simple or extremely difficult to consider, depending on the assumptions applied. Consider the case of suddenly changing the temperature of one surface of an object. If temperature gradients within the solid may be neglected (small, high k) If the only significant temperature gradient is 1d approximations of heat diffusion equation solutions. If significant temperature gradients exist in 2-3 dimensions finite element/finite difference method k.