A novel multi-component strain-gauge external balance for wind tunnel tests: Simulation and experiment

This paper presents a novel multi-component strain-gauge external balance to measure lift and drag forces as well as pitching moment in wind tunnel experiments. First, an innovative structure is proposed and its geometry is determined through a tedious trial and error scheme using finite element (FE) simulation. The sensor dimensions are thus chosen so as to acquire acceptable sensitivity and negligible interference error among the components considering maximum loading capacities. Appropriate locations of the strain gauges on the structure are determined via simulation. Then, sensitivities of the balance components are found using the FE analysis. Finally, the designed external balance is constructed and calibrated. It is found that the interference error among the balance components is less than 2.01%. Furthermore, the measured sensitivities of the sensor components are in a good agreement with the simulation results through which the design procedure is validated.