Air Bearing Balance with 1-DOF Spin Capability

摘要

This paper describes the development and testing of a one degree-of- freedom air bearing balance for dynamic wind tunnel testing. The balance permits test articles to spin without friction while making measurements of loads. Five load components are measured by sensing pressures in the air bearing film. The sixth component - rolling torque - is determined by sensing the current needed by the brushless spin motor to maintain a given rotation rate. The balance is also fitted with a novel auxiliary air delivery system which delivers air to the test model for pneumatic actuators or reaction control jets. The paper describes the design of the balance and preliminary testing in Physical Sciences Inc.'s (PSI's) automated calibration facility. Calibration results indicate that the balance responds linearly to applied loads. However, because it is impossible to manufacture a bearing with perfect uniformity, the balance must be calibrated as a function of bearing roll angle.