Controller tuning

Traditional thermowell selection methods based on velocity rating tables are no longer a match for the demands of modern processes, and a new approach, involving dynamic analysis methods, is needed. Starting with the simplest possible thermowell, a uniform cantilever subjected to a combination of vortex shedding and drag forces, the dynamic stresses are obtained for a complete range of flows. This establishes a basis for extending the standard thermowell stress model to cover a wider range of processes and flow conditions.