Using the Torque Characteristics of Dampers to Measure Airflow, Part I: Model Development and Validation

This paper describes the development of a mathematical model for predicting the aerodynamic torque characteristics of dampers. The model relates position, velocity, and aerodynamic torque so that one of the three can be estimated if the other two are known. The model is based on the theory of free streamlines. The accuracy of the model was tested experimentally. A wind tunnel equipped with a five-point pitot tube array was used to test the torque characteristics of a damper with an offset-blade construction. The model was calibrated with one data set and tested with a second. The experimental results demonstrate that the model accurately predicts torque characteristics over a wide range of operating conditions.